Author Topic: Baffling rattle,  (Read 1663 times)

Ian

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Baffling rattle,
« on: November 06, 2006, 01:22:51 PM »
I have a MuZ Skorpion Traveller with a top end rattle /very loud ticking ,it's louder on the cam chain side.

I've pulled the cam cover off expecting to see XBR type damage ( cam eating head and followers ) but everything has very light wear on it and no damage ?

And I've pulled the head off ,cam chain is in good condition valves aren't bent and seat nicely .

Has anyone any ideas as I'm running out of places to look for it ?






androo - must log in!

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Re: Baffling rattle,
« Reply #1 on: November 06, 2006, 04:49:13 PM »
sticking camchain tension adjuster??

Just a thought, no experience of this, my MZ motor has been fine for the 4000 miles I've had it.

a

Ian

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Re: Baffling rattle,
« Reply #2 on: November 06, 2006, 08:58:55 PM »
Good try ,
But the cam chain adjuster is as free as a bird ..

I bought it with the rattle ,thinking that there isn't a lot that goes wrong on these motors ,simple to fix ?
 

bullet350

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Re: Baffling rattle,
« Reply #3 on: November 07, 2006, 12:30:35 PM »
is the skid on the cam chain adjuster excessively worn? or are the valves in need of shimming?

bullet350

Steve H

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Re: Baffling rattle,
« Reply #4 on: November 07, 2006, 01:35:43 PM »
From memory the cam has an automatic decompressor mechansim, could this be rattling/playing up.

Ian

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Re: Baffling rattle,
« Reply #5 on: November 07, 2006, 02:31:32 PM »
I think I've found the problem !  :(

There is scoring down the piston in 4 places and on the liner .
Looks as if it needs a re bore .

The next question is what caused it ?

Big end or small end failure maybe at 38000 miles ?   £££


Steve H

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Re: Baffling rattle,
« Reply #6 on: November 07, 2006, 03:50:03 PM »
They are big pistons and tend to rattle around a bit. If its the original then 38.000 miles isnt to bad.

androo

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Re: Baffling rattle,
« Reply #7 on: November 07, 2006, 05:24:54 PM »


Big end or small end failure maybe at 38000 miles ?   £££



The story of my MZ:

Bought new (by "Chap A"), and after about 12,000 miles, "A" decided to ignore a knocking bottom end.  It eventually gave out when the big end wrecked the crankpin. 

Bought by chap "B". For a bit too much money.  He fancied a Supermono-type track bike.  Why the hell he chose a standard road Skorpion I'm not sure!!  He spent about a £1300 having the motor rebuilt and tuned at slipstream to 52bhp.  Bodywork was RS250 stuff, and it was used on track for a year or 2.  Anyway, following his divorce, he sold it to his neighbour, chap "C".

"C" is a bike fan, especially singles, and bought it just because it was interesting, and he likes trackbikes.  He had sold me the SRX I'm currently racing, about a year or so previously.

C converted it back to road use, but it wouldn't sell. 

Dr. "D" got it for a song, and although the chassis bearings were all knackered (yep, eee-every one!) its still good fun.

So Chaps A, B, and C all lost out somehow.  And the motors (although strong) aren't failsafe.

Hmmmmm!  Is there a point to this??  Sorry to hear about the scored bore.  I know of some tuned motors and associated fast bits going if you want to build it up.  They're still what I would call dear, but much cheaper than when new....

Cheers, good luck!

a

Ian

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Re: Baffling rattle,
« Reply #8 on: November 07, 2006, 07:30:05 PM »
Hi androo,

Sounds very interesting ,whats on offer ?

All though it's a traveller and I don't really want to tune it ,
This won't stop me putting fast parts on my sport !

So far I'm after a piston ,re bore or a cylinder barrel ,
I haven't looked at the crank and rod yet ,but I'm expecting the worst .

It might be cheaper to fit a replacement engine ?

Quote
« Last Edit: November 07, 2006, 07:41:27 PM by xbrmz »

guest18

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Re: Baffling rattle,
« Reply #9 on: November 07, 2006, 09:54:33 PM »
They are big pistons and tend to rattle around a bit. If its the original then 38.000 miles isnt to bad.

Hmmm that's a bit pessimistic isn't it Steve? (he says crossing his fingers). Mine is a good way past 30,000 now and still sounds nice and tight (crossing the other fingers and touching wood!!!) Mind you it gets warmed up and choke off quick and regular changes of good oil...

I didn't see the engine listed on Wiseco's website, is there a known source of replacement pistons/bores etc which doesn't involve remortgage??

Ian

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Re: Baffling rattle,
« Reply #10 on: November 07, 2006, 11:06:08 PM »
Don't worry I have no idea how this engine has been looked after ,
I've found 3 reports on MZ forums of the same problem , most seem to blame big end failure .
I'll be replacing mine if only for the peace of mind .

I would expect there to be standard over size pistons available ,though I've yet to phone BSA Regal .

Slipstream have 100 , 101 and 102mm Pistons
JE do 100 and 102mm  (£110 on TTS website )

themoudie

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Re: Baffling rattle,
« Reply #11 on: November 07, 2006, 11:39:21 PM »
Aye xbrmz,

Try Vic Eastwood's site mentioned elsewhere here. Same piston/ liner combo as XT660, SZR660, or Yam 'Grizzly' 660 quad.

Piston £90 - 110, liner £40 - 60. Fitting liner/honing to spec. by competant engineer £50 - 60.

Ensure honing to spec!!!!!!!!!!!!!!!!!! Wash in hot soap and water to remove ALL traces of honing abrasive, lightly oil.

Ensure fitted ring end gaps are spot on!!!!!!!!!!! Oil libreraly when assembling. Running in methods extensively discussed in previous posts on forum.

Regards, Bill

bullet350

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Re: Baffling rattle,
« Reply #12 on: November 08, 2006, 11:45:10 AM »
i don't know about other skorpion's, but my Sport had a mph speedo, that actually read in km's.
the face and everything said mph, but the trip and mileometer both read in kilometers, although it said miles.
my bike said 14000miles but it was actually 14000km.
just wondered if it was just mine. it was probably cheaper to but km speedo's and just change the face.

bullet350.

Steve H

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Re: Baffling rattle,
« Reply #13 on: November 08, 2006, 12:06:33 PM »
Hmmm that's a bit pessimistic isn't it Steve? (he says crossing his fingers). Mine is a good way past 30,000 now and still sounds nice and tight (crossing the other fingers and touching wood!!!) Mind you it gets warmed up and choke off quick and regular changes of good oil...
Perhaps I'm viewing it too much from a Yamaha air-cooled perspective (SRX). All the SRX engines Ive run have had slappy/scored pistons, maybe ist the frequency of engine strip down that make them more noticeable. To be be fair the RFVC engines seem to be more reliable in this respect.

Ian

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Re: Baffling rattle,
« Reply #14 on: November 08, 2006, 01:49:30 PM »
i don't know about other skorpion's, but my Sport had a mph speedo, that actually read in km's.
the face and everything said mph, but the trip and mileometer both read in kilometers, although it said miles.
my bike said 14000miles but it was actually 14000km.
just wondered if it was just mine. it was probably cheaper to but km speedo's and just change the face.

bullet350.

My sport has 24000 km on the clock and a cr#ppy mph sticker on the glass .
The traveller has a mph speedo face on it not sure if it measures km or miles .. yet to ride it !