Thumper Club Forum
Technical => Bike Problems/Questions => Topic started by: Ian on February 20, 2007, 10:21:45 PM
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My MZ just eaten another con rod either that or something just as expensive judging by the loud knocking.
It's heading for surgery in the next couple of days ,Nil by carb till then.
Has anyone tried these con rods ?
http://www.corsemeccanica.com/mz_skorpion.htm
If so will they stand up to a 102mm high compression piston ?
At $179.00 = £91.55 I could afford a box full ,The rate I'm going through con rods I need a box full !
The reason I ask is that a Carrillo is £264.38 :o(
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I thought A man of your means would have the Ti option??
Only £495 to you sir.
I'll get my coat
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I thought A man of your means would have the Ti option??
Only £495 to you sir.
I'll get my coat
That's $495 not quite so bad as £495 still more what's in the bank ......
I got round to draining the oil off , It looks like it's got glitter in it , 4 bikes and not one runner .
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As of one minute ago, there is a brand new still in wrapper Carillo rod for a Yamaha Raptor 660 on Ebay Motors, USA.
It is being sold by someone who abandoned a project, and has a buy it now of 95 USD.
Item # 170085445336. Hope this helps you, as it sure is strong enough to take anything on top.
I assume it is fully interchangable with our Skorpions, but check with someone you trust.
I can also state that here in the US many people are having good luck with complete Hot Rods crank and rod assemblies for Yamaha Raptors.
They cost 250 USD, and a friend of mine has sold eight of them to Raptor Racers in the last year, and has encountered no problems.
They are lighter than the MZ cranks, and the rods are reputably as strong as Carillos.
The cranks come fully assembled, and my friend put one on a stand to check it out. It was within .001 in every direction, and the quality is top notch.
Hope this helps you.
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Thanks for that bikeseamus would of been Ideal .
But the seller won't ship outside the US .
There must be something as good as a Carillo rod available in the UK ? at a little less ££
Raptor cranks have smaller ends than the Skorpions
So I would have change the bearings and replace the alternator this would eat any saving made on buying a Raptor crank assembly :(
It's looking like my credit card is in for a beating !
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BHuy it - ship it to Seamus and he ships it on...?
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BHuy it - ship it to Seamus and he ships it on...?
I would certainly do that, to help a fellow MZ rider.
These things have a way of coming around, as we have better access to some things, and vice versa.
You make the call. I can simply forward it on to you in the method of your choice.
No sweat.
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The new Carrillo rod went for 56 USD, so you might keep an eye out for one on ebay USA.
Not many people will refuse to ship overseas. The guy was a clown, and undoubtedly lost money as a result.
A guy in Denmark wanted it also. The seller was a California Raptor racer wannabe......probably doesn't know how to follow through on anything.
Corsemeccanica are good honest and competent people that know and build good racebikes, if that is a better option.
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BHuy it - ship it to Seamus and he ships it on...?
I would certainly do that, to help a fellow MZ rider.
These things have a way of coming around, as we have better access to some things, and vice versa.
You make the call. I can simply forward it on to you in the method of your choice.
No sweat.
bikeseamus,
Thanks for the offer of shipping it on to me .
If I'd had the time to check the forum in the past couple of days I would have bought it !
Thanks again........I will keep this in mind for the next one...
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The new Carrillo rod went for 56 USD, so you might keep an eye out for one on ebay USA.
Not many people will refuse to ship overseas. The guy was a clown, and undoubtedly lost money as a result.
A guy in Denmark wanted it also. The seller was a California Raptor racer wannabe......probably doesn't know how to follow through on anything.
Corsemeccanica are good honest and competent people that know and build good racebikes, if that is a better option.
Oh !*@@@@! !!@@@@@@@ *!@* That's less than £30.00 ,he gave it away !
I missed out big time on that !
I though I might get in touch with Corsemeccanica if nothing else shows up on EBay by the end of the month .
Bikeseamus ,
If there's anything You need UK assistance or shipping give me a shout anytime.
The past few days I've been camping in the garage !
Fitted a XBR engine in the frame.
Re-built one of the Skorpion engines but it's not in a bike yet....Only because I dropped it on my hand ,
Nothings broken just a few scratches on the front of the engine...Hand hurts like hell.
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Thanks
I'll keep an eye on this forum, and do what I can to help. An alternative for your rod problem is maybe use a stock raptor rod. They rip up to 10,000 RPMs without a problem all day long, so they are bound to be stronger than the MZ spec rods. I may be able to pick the rods up fairly cheaply here, because many people build up their Raptors here for racing.
Again......... ask someone you trust who gets their hands dirty on them for a living. I can't say for certain.
You may be aware that the new Raptors are now 700ccs, and are now injected. What benefits this may hold for us in the future, partswise, I don't know, as I haven't conducted any research yet on interchangeability.
I will say, however, that it is always a rush among racers to get the biggest and best to win, so we may just be in for a massive dumping of 660 parts of every description here.
As they say............. Stand by for further developments.
As for something you guys may have access to over there, I will ask whether you in the UK have been recieving fairings on sportbikes that contain the small passing lights in them.
All North American spec fairings have that opening blanked out with a plastic plate, including the MZs.
Many of us would love to be able to install a light into those openings, and the part is unavailable to us because of some bureaucratic horseshit I am unaware of.
My 93 models FJ 1200 and TDM 850 and my 98 YZF 750r would all take the same light, but I don't know which bikeyard in the UK or Europe ends up with the cracked up bikes, and would mail parts to North America.
Any assistance on this would most certainly be reciprocated, without fail.
If anyone has any questions or requests, just ask. Cool for now. Thanks.
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Hi
I did a little research on who is doing what with the 660cc Yamaha engine over here, and this is what I came up with.
Crank Works, in Arizona, and Craycraft Racing seem to be engineering giganto horsepower into their engines and have been taking most of the big tall blue trophies and cash away from the races.
Craycraft Racing has a nasty 760cc engine package that rips long and deep holes in the ground, and have built the World's Fastest Raptor,and Crank Works of Arizona builds nearly indestructable crank assemblies for all types of racing.
Both have Sterling reputations and are reputably very friendly and helpful, like most champion motorheads are.
Crank Works probably throws away more good Stock Raptor Rods than anyone else, and may just sell them cheap and send them over for a song.
It may be a source of stronger MZ rods, very cheaply obtained.
Crank Works also stocks Falicon, Pro X, Carrillo,and Hot Rods connecting rods, any of which would certainly solve anyone's
weak MZ rod problem. They are also developing a new rod of their own for 760cc or more race kits, and it looks like it will be stronger than a Carrillo.
Check out the photo of the new rod on their website at www.crankworks.com.
It is dead serious business, and a beauty to behold.
Hope this helps someone over there, as bikes are infinitely more fun when they aren't broken and can be properly thrashed without unwelcome knocking or explosions.
Besides that, it is inconsiderate to dump engine oil and pieces on the road.
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hello,
Mike Edwards has just got his 84ish bhp motor running.
From his site : www.gordonsalive.com
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Martin and Roy at Slipstream did their magic it should be between 82-84bhp.
I think I will be able to feel the difference for sure!
It now has a Raptor crank so will spin up quicker and been bored and stroked to take the capacity from 659 to 760. All the starter gears and starter motor are gone, the water pump has been replaced by a electric one too. The clutch basket has been replaced with a 6 spring type to take the extra power. Lighter larger valves, lumpy cam and a pair of 39mm Keihin carbs all help
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cheers
a
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Hi Andy,
Is there a hand full of salt with that ? rub gently ?
Well I've got 3 con rods that are shot ! The best one lasted a whole 15 minutes of riding.
I've only killed 2....
Hi Bikeseamus,
The light your after is it the little one at the top of this fairing ? Ebay item : 110099281415
If it is ,it's the same one fitted to the Skorpion sport only the other way up ,they don't appear without the fairings on Ebay very often you might do better buying a new one from BSA regal I know that they ship to the USA . I would buy only one just to make sure It's what your after !
Or I could phone a few breakers for you...
Re : Raptor con rods,
I was told that they are the same part as the MZ /Yamaha con rod by a guy that works at Slipstream racing.
I need to put something stronger in as I don't want to do it more than once on either engine ( this week )
With the lighter crank they might have an easy er life, But for 10,000 RPM I don't know I'd be expecting it to fly out.
I like the look of crank works ,As soon as I get the cash spare I'll be dropping them and Corsemeccanica an Email ,
Hopefully the postage won't be to much.
I'll have to make do with the car for now :(
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Mr XBRMZ
That's the one.
Do you have those little units wired into the passing button on the left handlebar controls in Europe and the UK?
I'm sure I can install some kind of penetrator bulb in that little cutie pie and it would help me at night, but if your factory yamaha parts over there are anything like ours they probably want about a jillion bucks for that liddle thang.
It's certainly no panic, but if you run across any in your junkyard journeys you might keep me in mind.
Seems as though the yards would end up with quite a few munched up YZF, FZR, FJ,ZX, and other sport type fairings.
It does look as though it would interchange with the MZ.... maybe there is a universal size you all use in the UK and Europe?
Glad you told me Raptor and MZ rods are identical, though I am trying to think how a decently balanced engine of any flywheel weight would be harder on an identical rod at 7200 RPM than 10,000 RPM.
I guess a heavier flywheel takes its toll, which makes me want to switch to a lighter Raptor Crank, because my friend the local Yamaha dealer has had no crank problems since 2001 in any of the hundreds he has sold, and nearly all have been mercilessly thrashed and raced.
My MZ shuts down at around an indicated 7200 RPMs, because I've been frightened away from hooking my extra TDM CDI to it by hearing about experiences like yours.
Have you been knocking rods out of it at those kind of Revs?
I am curious, because I have always found it prudent to listen and watch how things break.
I don't want to build the engine up but once, if possible, and it seems I can buy good tight low hour stock raptor cranks with rods over here all day long for about 25 USD plus postage on ebay, and dual float raptor carb sets for about 50.
Better to have 5 3000 buck bikes than one 15000 buck bike, if you hear me on that.
I do appreciate your running/passing light information.... which is it.... ? Thanks again, Jim
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Hi Jim,
Parking , pilot or side light ,Normally wired to come on with head light also it comes on when steering lock is on 2nd notch ,
Very low wattage bulb ,not enough to light the road.
Phoned BSA up this afternoon your looking at approximately .......
£15.50 for a new complete parking light and £5.00 postage to the USA , Postage is estimated might be more or less according to weight and quantity. Not to sure what that is in $
Will phone the breakers tomorrow to see what they sell them for.......A lot of the Skorpion is Yamaha branded MuZ .
I can't see why the rods go ,
Sport was starting to rattle I've owned it for 3 years 24000 Km's never been through the red line ,I don't know what the previous owner did to it..
Bought a traveller with a rattly engine 38000 miles ,little end shredded and scored barrel. Stopped using sport expecting the same sort of damage happening soon.
Bought a re-built XTZ engine 102mm high compression piston ,re-ground cam ,standard con rod ,I wasn't sure if the con rod had been replaced nether was the previous owner ...
Fitted it into the sport it lasted 15 minutes of leisurely riding ,banging like a drum.
It would be interesting to find out what the extra parts would cost to fit a raptor crank.
Main bearings ,starter gears ,etc
There is lots of MZ 660 info on : http://www.mzriders.com/mz/
Cheers
Ian
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Ian
Mysterious indeed. No question the 102mm high compression piston may be harder on a stock rod, but I'm wondering if it's oil related?
I run 20 50 Valvoline 4 stroke motorcycle oil, Rated JASO and MA on the specs, MA being capable of resisting molecular shear in a common gearbox, and the JASO spec is the highest valve train and cylinder film spec available here in the US.
I also run Yamalube 20w40 with no problems, and a coolant with an anti microbubble compound in it for better cooling, like the racers use. Over here it's called a coolant "wetting" agent.
I will admit that I regularly bump against the rev limiter...... actually use it for a shift point in "spirited" riding.
I'll bet if you get one of corsemeccanica's rods you will be OK, and I am curious which one they use.
You can trust them, as you can your man at Slipstream over there. I'm certainly no expert on these mills.
Yours is the first problem I have heard of with the stock rev limiter in place, but like you said, it is impossible to tell what the previous owners did that may have damaged the engine.
Sounds like your ace at Slipstream will have a good grasp of what is involved in a Raptor internal parts swap, and if you see what you need on ebay over here, and the seller is a jerkoff that won't mail overseas, let me know and I'll help you get what you need.
How's that? Cool for now, Jim
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Hi Jim,
I've been using Fuchs Silkolene 10/40 ,As recommended by my local bike dealer.
I'm afraid I've had no luck finding you some pilot lights from my local breakers ,
Phoned 2 up this afternoon ,1st one wanted to sell them with the fairings ,
2nd said he hadn't got any so they must be rare ? yeh right.
Will let you know if I find any..
If you visit the link in my previous post you'll find I'm not the first one with this problem ,even without the 102mm piston.
But it could all be down to previous owners neglecting oil changes and a heavy right hand
The only reason I'm not using Slipstream is that if I bought 2 Carrillo rods and had them fitted to the cranks ,
I can buy another MZ Skorpion Sport for the same money ,at least I'd have lots of spares.........
I've Emailed corsemeccanica about their connecting rods :)
Cheers
Ian
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No joy with Corse meccanica , Won't ship to the UK...........
But they did say
"The connecting rod you are interested in is quite suitable for your application - we have racers in the US running these on 104mm high compression engines without incident. The stock con rod has a history of failure once the engine is tweaked."
Not bad as you can buy 2.5 for the price of a Carrillo ....
And sent me a link to Barker's Performance ,
I've just sent them a email ,might have more luck this time as they make them ..
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Aye Gentlemen,
Whilst running an SRX600, Ducati singles or BMW F650 and not the Yamaha 660 motor, may I suggest that 'ringing its neck' through the gears may not be the problem. Plonking it in 'top' will knock the stuffing out of any big single rod/bigend of over square dimensions. Ducati's singles, even with expensive Carillos etc. cry "Nuff" if plonked. The SRX below 3500 in top feels decidedly rough, it also helps break up that naff 5th gear we have! The BMW F650 is similar to the SRX.
Maybe lowering the gearing a tooth or two on the rear sprocket might help to keep the revs up on the congested and speed restricted roads most TC members endure for much of the time.
Maybe all tosh, but!
Hope you all get sorted and thanks for the offers from across the pond!
Regards, Bill
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Are you insinuating I'm plonking Bill ?
Can anyone explain this ?
Carrillo connecting rod in the USA $215 aproxamately £111.30
Carrillo connecting rod in UK £264.38 aproxamately $510.51
I know that they make more than one type for the Yamaha 660 engine ,I wouldn't think there's that much price difference .
And it can't cost that much to ship them !
Still no luck with getting a US company to ship to the UK ..............
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Each is individually wrapped by a virgin (hard to find in the US) in the finest Organic silk, before being pakaged in a hand hewn aquamarine box with solid 24 ct gold hinges. They are then packed individually in a climate controlled container and individually shipped, with four further dusky virgins taking care of its every whim up to delivery. Upon delivery a crack team of mechanics strip your bike and fit the rod, replacing each and every bearing for a hand selected, perfect unit, blueprinting as they go, where as in the US they just wrap them in oil paper and a cardboard box before sending them Fed Ex
R
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That's just being silly ! 24 ct gold hinge .
I can understand 4 dusky virgins ;)
It must be a pain having to find 4 more for the next delivery ......
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They had to close their operation in Port Talbot after two deliveries - and then one was returned because at least one was lieing.
R
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Aye xbrmz,
No, I'm usually the 42 carat plonker! An old Aerial HT was the best, max retard, 1st gear and it would spin the back wheel whilst trying to climb a brick wall. However, a pure B whilst trying to control over boulders, spit you off and keep going, even when lying on its side!
As for the price of the sacred rod 'staff of life' in a single. When shipping from USA the following maybe added to the cost of the rod. A fourteen percent (14%) import duty on the price of the rod, the cost of the carriage, plus VAT @17.5% on the total sum of the aforegoing. Even with the 'strong' GBP they ain't cheap.
Pattern rods as I and others have found to our cost can also prove expensive, when playing 'peek-a-boo' through the cases or bottom of the barrel! :-(
Maybe some discreet correspondence with this company below might be fruitful. One off specials from £140/rod plus VAT.
Thunder Engineering, Leicester: stevecampbell@thunderengineering.co.uk
I have no experience or association with the company, caveat emptor.
My regards, Bill
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Hi Bill,
I'd forgotten the import duty ,I wonder if one in parcel post would sneak through ?
Thanks for the Email address I'll keep it to hand .
At the moment I'm waiting for replies to Emails I've sent to the USA.
I've also a few phone numbers of Raptor dealers and tweakers in the UK.
I know I'm doing it back to front ( plonking ) but the prices in the US are appealing ,as I'm after 2 rods.
I'm not bothered who makes them as so-long as they don't turn to butter when I start the bike ..........
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The duty and VAT etc is supposed to be collected by who ever delivers the package - ie Royal Mail, Securicor - in my experiance most are not geared up to deal with the handling of cash etc. So long as it is being delivbered to a 'home' rather than a 'business' address you may find it OK.
R
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That sounds hopeful on the VAT etc Rog .
So far I've sent over 10 Emails to the USA ,1 reply ,Is there a national holiday over there ?
And 15 Emails to raptor custom parts and tuning dealers in the UK this afternoon.. 1 reply.........
Still not getting anywhere...............
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Oh and the tax etc is payable on the value given by the sender on the customs declaration too. If you trust the post not to loose it and the sender is willing - this is illegal BTW and not only will interest the usual tax people but the VAT (when I was in business I was told "upset the customs, upset the inland revenue but NEVER upset the VAT ") - a much lower value can be put on the ticket. I understand a number of the US cycle companies are sending £1000+ frames to the UK with £200 tickets on them. IF you get charged for the Tax it is a lot less, BUT if the customs man is clued up, or the postie is, you are looking at fraud charges.
R
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OK
Given these insane rules, howsabout we do this?
I buy the rod of your choice.
I send it to you as a friend, not a business.
I charge nothing, make no profit, and am not in this bike thing to make money.
That works for me if it works for you, and it seems to me that simply stopping by the
post office and forwarding it would take all of five minutes, and the post office is 1/2 mile from my house.
In other words, no big deal, and the greedhead jerks gouging you for the rods can gouge elsewhere.
Reasonable profit is one thing, gouging is an entirely different kettle of fish, and it stinks.
Besides that, giving cash to greedheads empowers them.
So fuckem and feedum fish heads. How's that?
As for oil, you couldn't pay me to run 10 weight oil in a motorcycle, unless it was 20 below zero outside, and I would never run car oil in a motorcycle.
Over here, they have restricted the additions of phosphorous and zinc in motor oils.
If these are present in a worn out engine, they burn in the combustion chamber and pollute the air. OK.
On the other hand, you or I could generate 46556446475757875 times the zinc and phosphorous into the atmosphere simply by welding on a series of galvanized handrails, which has not been restricted.
Phosphorous and zinc are among the best additives in any motor oil, but are only allowed in vehicles without catalytic converters here because they could concievably clog them up, and an engine that smokes would be pumping these bad components into the air.
That's why the EPA has put the rule forward.
We who run vehicles that share tranny oil with the crank need these additives more than anyone, as transmission gears shear oil lubricating long string molecules more than cylinder and bearings do.
Zinc and phosphorous both have tremendous molecular shear resistance, so if we run oil without them, everything breaks faster and easier.
Over here, MA on the oilcan says it all, and if the oil can't pass JASO valve train torture tests it is garbage.
Maybe we have access to better oil over here, I don't know.
One thing I do know.
Any oil over here that brags about greater mileage on the can has short molecules that will destroy cams, bearings, rods and starter clutches on bikes, as they have no film strength and no molecular drag.
You may experience slightly better fuel mileage because thay are a little slipperier, but meanwhile your engine is grinding itself into junk and everything will wear out and fail at an accellerated pace.
SAE rates our oils over here. It stands for Society of American Engineers, so you probably don't have that rating on your oils.
In the absence of that, I suppose you guys should run oils that are specifically engineered for four stroke motorcycles.
Some of this information is sort of guarded, and oil companies over here don't like to talk about it, for obvious reasons.
I know a guy who designs oils for a big company, but he also loves and builds high horsepower bikes and streetrods.
That's where the information comes from. Cool for now. Jim
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Correction
SAE stands for Society of Automotive Engineers.
You have that over there?
PS. Thanks for checking up on the running lights, but don't worry about them too much.
Should you someday run across a breaker with enough sense to sell them reasonably, we can go from there.
In the meantime, I will innovate with any number of lighting options.
Thanks again, Jim
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Just out of intrest what the thing with these MZ con rods.
What fails Big end. Small end. Most single cylinder big ends will knock for quiet a while what the thing with the MZ ones
Ken
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Just out of intrest what the thing with these MZ con rods.
What fails Big end. Small end. Most single cylinder big ends will knock for quiet a while what the thing with the MZ ones
Ken
Hi Ken,
The small end and the piston pin wear allowing the piston to be dragged down the bore leaving scoring in four places.
Or is it the piston rings wearing out that allows the piston to be dragged ?
Some of this might be down to previous owner neglect .
Basically the standard con rod is the weak point of the engine .
It's also the same con rod in SZR and XTZ so don't buy a neglected one.
If you fit a high compression piston a standard con rod lasts 15 minuets of gentle riding this was a perfect con rod !
I've since been told it can snap as well !
On top of that it costs a lot of £££££££££££££$$$$$$$$$$$
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Hi bikeseamus,
Are you tyring to do my head in with all this talk about oil ?
Just been to the Silkolene web site they recommend.
Skorpion and SZR 15/50 or 20/50 XTZ 10/40
Obviously I need to change to 15/50.
Regarding the con rod ,I've sent loads of Emails ,today I've received 3 replies ,all from the UK .
1st one, rod kit £92.00 ,fitting £112.00
2nd one, rod kit £189.71 + VAT fitting around the £650 mark + VAT
3rd one, new race rod on the crank fitted £200.00
1st and 3rd need to answer a few more questions before I trust them with my cranks.
Not to sure what the 3rd one is quoting £650 + for ?
Jim,
If there con rods aren't of a known make I'll take you up on your kind offer of shipping them to me.
Many thanks...........Ian
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My tuppence worth:
I have a 1998ish Skorpion, engine thus:
Owner1 wrecked it- bottom end got noisy, he kept running it, eventually sheared the crankpin
Owner2 bought it, sent it to Slipstream, hi comp piston in 660 bore, flowed & ported head, dynojet kit in standard carbs. New bearings throughout, new standard rod, crank trued, new crankpin. 52bhp at wheel, used as a trackbike for a couple of years, but well maintained.
Owner3 is me, 6000 miles later its lovely, bounces off the limiter with ease, no probs re lower end with hi comp piston and standard rod. Fairly regular oil changes.
So I think if abused (neglected and crap/low oil?) the bottom ends can go. However, my motor shows (touch wood!) that if assembled correctly, standard rods and bearings are fine for a lightly tuned road engine. I wouldn't want to change the CDI or remove the limiter- maybe that is the saving grace?
Ian, have you put a post on the Yahoo MZOG group- those guy seem to know their 660 motors.
Also, my 620 SRX (similar engine) has a standard rod, and its also good (tho maybe not at the end of the season!). I am a bit more worried about this as it will easily go WAAAY into the red, unlike the standard engine, but will just go easy on the "loud handle" and try not to wreck it. Its going back on the road come the end of the season hopefully.
Thats all, cheers for now. Good luck matey, sounds like your running a bit lean on that of late.
a
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Hi
You have me thinking now. Its hard to beliver that MZ could make such a weak conrod. I have never worked on one of these but is it the Rotax engine? I have had engines where the gudgon pin is fixed in the conrod and turns in the piston and some that turn in both. it seems unuasual that these should wipe out a con rod so quickly. It major if you having to replace this so often. Does it run on a bearing in the small end?
Ken
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Hi Andy ,
I'm surprised that Slipstream put a high compression piston on a standard rod , Has it not been over bored ,+1mm +2mm ?
As it was Slipstream that told me that if my high compression piston was fitted to a standard rod it stands a good chance of snapping the rod !
If you wish you can read my post on MZ riders forum ,Wonky works at Slipstream.
http://www.mzriders.com/mz/viewtopic.php?t=1765
I haven't tried MZOG ,If I join any more forums I'll start getting mixed up ! I've been meaning to cut it down ,to many interests.
Hi Ken,
It's a Yamaha 660 engine not MZ ,There is no bearing in the small end ,Up until now I've never replaced a conrod in any bike engine.
Ian
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Odd, Assumming the piston is the same weight and the engine stays within the same rev limits, then the conrod is under the same load. Granted the engine will have a greater output but this will compress the rod, not stretch it and snap it. The SRX engine is a close relative to the 660 motor and from speaking to a guy who worked for a tuning company in Holland the standard Yamaha conrod is strong enough for the stock rev-range but can stretch quite a bit if revved to hard. He had spent a lot of time on his works dyno and I was inclined to beleive what he was telling me.
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If it's stretching and snapping ,wouldn't it take the valves out before snapping ? could be a few seconds earlier I suppose.
If it's being compressed ,couldn't it buckle before snapping ?
Sorry just thinking out aloud !
I really need to turn the PC off and spend more time in the garage ,
All this typing isn't good for me...........
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My understanding was that he knew how much the rod was stretching by the fact the piston was cleaning the carbon from the squish area. From memory he was running squish somewhere between 0.5 to 0.8mm. Valves should have more clearance than this.
I'm not clear how a worn little end would cause scoring in the bore. Ok it can allow the piston to rock. Looking around this type of seizure seems to be referred to as 'four corner seizure' and is associated with overheating.
http://www.kartingtechnic.dk/html/piston_seizure.html (Yes I know is for two strokes)
Whats your oil pump like ?. I seem to remember Steve Lake have a few siezures which were down to a duff oil pump
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Ian
It looks like you're in luck, Buddy.
Vesrah now makes a high performance connecting rod kit, and a dealer on ebay who ships WORLDWIDE is starting to sell them with opening bids at 84 USD, and it looks like it comes with a new crankpin, too.
I like Vesrah stuff, and I'll bet this new kit will be stronger than stock. Check out item # 130089953731.
Hope this helps. Jim
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Hi Andy ,
I'm surprised that Slipstream put a high compression piston on a standard rod , Has it not been over bored ,+1mm +2mm ?
As it was Slipstream that told me that if my high compression piston was fitted to a standard rod it stands a good chance of snapping the rod !
If you wish you can read my post on MZ riders forum ,Wonky works at Slipstream.
http://www.mzriders.com/mz/viewtopic.php?t=1765
Hello Iain,
No overbore, just a standard size Hi comp (Arias?) piston. I understand its probably better to have a better rod in there, but at least its a new rod. And if I were spending a grand or so on a motor, I'd probably put down about another 250 or 300 quid for a top spec rod, but I didn't get that option!
Just a cheap bike! :D
I've spoken to the guy at slipstream quite a lot, and I agree with what he says. Especially as it was built as a track bike. But it was only trackdays and occaisional road use if needed, not a serious top spec 80bhp racer. Also, I am keeping the rev limiter as stock, so am not too worried.
And if it goes pop, it goes pop. And I'll put the wheels on the DR and make a supermoto! The bike owes me nothing, and the cycle parts aren't brilliant anyway.
But (touch wood) it'll be ok and keep getting me to work. Noisily!
Re. Vesrah kit, in contrast to bikeseamus, i've never been that impressed. Mind you I've only bought gaskets and fork selas, and maybe a twistgrip. It always seemed a bit like typical pattern stuff to me- ie. ok but only ok. Fine for a clutch cover gasket, not fine for a conrod!!
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I've used Vesrah valves and clutches and gaskets and oil filters forever, in everything. They aim to hit the market with stuff at least as good as anyone else's, but at a smaller margin of profit.
They have been the oem manufacturer of millions of stock components for every Japanese Maker, and will build to specifications for anyone.
In 40 years, I have never seen a defective vesrah part of any description, and have used their gasket sets and valves and bearings for all kinds of engine rebuilds, since 1977.
Since they have jumped into connecting rods, I'll bet they are the best to be had for the money, and if they say they are high performance, they will be stronger than stock ones.
Every year I speak to the Vesrah People who come over from Japan to attend the International Dealers and Manufacturers show in Indy, and I'm impressed with their focus, knowledge, and enthusiasm for all the new stuff they are coming out with.
I have asked them about metallurgy, and their eyes light up like Christmas Trees. They enjoy their jobs and are obviously well compensated and respected for their efforts, which indicates a well run company.
Their company is based upon solid engineering instead of slick sales, and they will be in business until the World ends, and I'm glad of it.
There may be some junky stuff in the bike world, and there are different markets to aim for. Some people want visual sculptures over practicality, like Ducati. Some like to pretend their stuff is just naturally better, like BMW. Some like to make rare high end status symbols, like MV or Benelli or Ferrari in the car world.
All cool with me.
Ian wants a strong connecting rod for a reasonable sum, so I thought it might be a good idea to let him know Vesrah has put their dog into the hunt.
Vesrah won't risk their fine reputation by building junk. It will never happen.
I'll bet you a case of the beer of your choice that the new heavy duty Raptor Rod they make is at least 10% stronger than a stocker and costs more than 10% less to buy.
It may not be a Carrillo or a Hot Rod in strength, but it sure as hell will be better than a stocker.
If Ian doesn't want to steam his MZ up to 80 rear wheel HP, and wants to put some money elsewhere, it is something for him to consider..... that's all.
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Apologies for the delay in responding to your posts everyone but I typed most of this out the other night /early morning then hit refresh ,definitely time for bed when your doing things like that !
Hi Steve H ,
A very interesting article ,It cover all the symptoms perfectly .
Even if it's meant for 2 strokes.
Unfortunately I don't know the history of the engine and seeing the play in the little end ,that's where I pointed the finger !
All parts will be checked before re-building
Hi Andy,
It's probably the extra 2mm ?
Just that bit to much for the standard rod and maybe way to much for a used one.
Yes I have to agree with you on Slipstream.
I just don't agree with their Carrillo rod price as far as I can see there no excuse for a 140% extra for UK buyers !
Hi bikeseamus,
Thanks for the link to the Vesrah con rod.
But I'm not sure about putting a 102mm piston on top without somebody known for building 660 engines recommending it.
It would be fine in a standard engine though.
I've used Vesrah parts before never had any problems ,it's very tempting.
As for 80bhp I can get my self in enough trouble with a standard engine.
I only bought the one with the 102mm piston because it was the right price and I thought it would be a quick way of sorting the travellers engine problems out.
How wrong was I ?
It's turned in to a money pit and it is the first time in 17 years my other half has got really P off about my bikes.
In fact it's got so bad that I have thought about breaking the traveller for spares .
At the moment the two Skorpions are cowering in the corner at the back of the garage under tarpaulins having had their harts riped out.
One engine is on the floor and the other is on the work bench less than half way to having it's crank removed .
So far I've had 2 offers from the UK to fit con rods ,but they have not responded to emails as to who makes them.
I've just had an email from Barkersbar "yes we can ship them to the UK whenever you need them"
I think one of their rods will be finding it's way over this way.......The only problem left is finding someone to fit it.
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I've just picked up a cheap bottom end ,it all looks in good condition.
This is going to be used to build a standard engine just to get a bike back on the road.
None of the people that said they could supply and fit a heavy duty con rod have got back to me or replied to my last lot of emails ,Since I asked them who makes the con rods that their supplying .....thanks a bunch......
So running a 102mm piston is not going to happen for a while :(
I might leave the money pit till the winter........It all depends on my free time........