SRX600 rebuild

[guest1972]

Ello all

After posting here for a rolling frame for an SRX600 project, I bought a 'bike in a box' from a nice guy called Chris in the midlands. I thought I'd post my rebuild progress here for posterity.

I know some people on this forum although I have lost a LOT of hair since we last met (France trip in 2003 - I was on a blue 3AJ Tenere). I recall good times, endless sodding about by the Frenchies, and Mont Sant Effing Michelle in miniature.

But back to the box: everything appears there except for the brake calipers and a few minor bits & pieces. Chris and I agreed to leave the calipers behind as they were soaking in a tub of diesel - I didn't fancy a 5-hour drive home to Devon with them in the car.



I am seeking to reclaim my lost youth, by rebuilding an SRX I rebuilt in Australia for most of my 20's. I found an ad dated 2009 which was selling my actual Aussie SRX - useful as I do not have any pics of the work I had done to the clocks, and had forgotten that I had moved the ignition key to below the frame rail. Here's the ad (photos don't do it justice): https://caferacers.wordpress.com/2009/02/19/1987-yamaha-srx600-cafe-racer/#comment-2297

Bits I have bought so far:

• Ikon shocks - from this seller on eBay: http://stores.ebay.co.uk/brooksbarnmotorcycles?_trksid=p2047675.l2563
• Single seat hump (and oval tail-light) - from this seller in Germany: http://ricambiweiss.com/en/yamaha/207-27-race-tail-unit-seat-rear-yamaha-srx600-srx-600.html
• XS650 447 front wheel, twin disc wire - from Germany eBay

This SRX is going to be wire wheeled, but retaining original brakes and rim sizes. I have a Tenere rear wheel which I have compared to the standard SRX one - the Tenere appears 20mm too wide however I am yet to take more careful measurements to see if it could be persuaded to fit. I think I have the front wheel sussed thanks to this post: http://www.thumperclub.com/smf/index.php?topic=5559.msg37060#msg37060.



It's also going to be single-seat only, and 'open' with the centre triangle panels removed. So, no airbox or battery and some sort of rear hugger. To this end I have ground off the mounting lugs for the centre panels, and also the top rear footrest lugs. I am contemplating grinding off the seat locking cross-piece too, but will wait to receive the single seat hump to see how it fits. Also considering welding a couple of small lugs onto the swingarm to mount the hugger - but yet to find a suitable 18" donor part.

Undecided as to whether to powdercoat or 2-pack paint the frame. I have had bad experiences with powdercoating - the thickness causes issues with mounting the engine cradle chassis members, and the pressure of tightened bolts causes cracking.

The engine that came with the bike has had a violent visit from Mr Brokenchain, cracking the cases. Fortunately I have a spare set of XT cases which should fit. The engine is sitting on my workbench awaiting stripping. Planning on getting it vapour blasted and left as raw ally - clear coat tends to do more harm than good in my opinion. No other engine mods initially although am also considering replacing the crank main bearing to improve longevity and handle more power for future mods.




So far I have stripped the frame and ground off the unwanted mounting lugs - next I need to decide how it will be finished. Here it is sans lugs.



I expect that this rebuild will take some time... if I am riding it this time next year I will be very happy.

[timbo]

Good luck with all that's ahead, please keep us all informed 

[Moto63]

Looking forward to watching/reading your progress Baz , good luck,  Michael

[guest1972]

...told you this was going to be along rebuild...

Stripped the engine but then... what next? Too much thinking about time and cost, e.g. should I replace the big end bearing or is it fine as is? Also thinking about some of the problems with the 1XL/1VJ engine (5th gear + cooling to the rear of the piston, weak cylinder studs), which were addressed in later models (e.g. 3AJ and 3TB).

In the end, some late-night eBay cruising revealed a running 3TB engine out of an electric start XT600e for the princely sum of £360 including delivery. It's on its way to me in the back of a van. I just need a TCI (CDI) to make it run - he says with some hope. I'll junk the e-start and use the SRX side cover and kickstart mechanism. That's a significant step forward, maybe I will have a runner by spring.

Other stuff I have done:

• cut the lugs for speedo off the top yoke
• bought a seat hump
• bought a TDR250 rear spoked hub - although it does look rather weak compared to my XT600 rear hub...

Also done some research on styling, taking my cues from these two:

• 'open' frame, black wheels, rubber fork boots from the SRX
• black is black is black look from the 2-stroke, oh and the orange tank

More soon, I hope...

B

[timbo]

Loverly bikes! I see there's an SRX400 for sale in Killarney for £900.Thank goodness Killarney is a long way away from me, or anywhere really 

[guest1972]

Second-hand 3TB engine arrived today. Courier rolled up the drive 5 minutes after Mrs Me left with the kids - perfect timing as now I don't have any awkward explaining to do.

Q. How many engines does a man need? A: One more (always).

When it arrived it was in a rubbish bag and was a bit wet. All the ports were plugged with latex gloves, but the oil hoses and crankcase breathers were not... An exploratory finger in the exhaust port (ooh er) revealed it was wet in there. Fortunately the valves are closed but I think it would be wise to pull the head. Going to let it dry overnight before turning it over.

Also progressing with the frame - cutting bits off and welding other bits on. Wheels are at a local shop getting the old tyres removed. Hoping to get the frame and wheels to the powdercoaters in the next fortnight.

[guest1972]

I claim progress... of sorts.

There is an excellent bike road half a mile from my door, and all I can hear on weekends is the roar of bikes. Motivation.

I have not been idle. Bought and fiddled with this blasting setup:



I've been using soda, which works OK but does have it drawbacks - I'm going to create a new post on this with my findings.

I got hold of some proper old skool dichloromethane-based paint stripper, which I hit the wheels and calipers with in preparation for blasting. Then blasted them with soda.





I'm doing the calipers because they are small and good to learn blasting on. The wheels fit well enough in the cabinet, but are a bit unwieldy. I have done one wheel but now run out of soda. At £40 for a 25kg bag it isn't cheap, I am going to try plastic next.

Always thinking ahead, I bought these beauties. They are 31s as I have read that 33s are too big for a street engine. I need to be able to run them with a largely stock engine. I want to get rid of the stock carbs mainly because I want to ditch the airbox.

[Steve Lake]

I'd be interested to know how the blast box works, and if it does the job would you hire it out?
The CR's should work a treat, got a pair on our track bike... 33's but it's a fairly high state of tune... well pleased with them.. look the biz too.
good luck with the project

[guest1972]

I knew this would take some time...

Re-motivated now due to plans to emmigrate to Australia in a couple of years. This has prompted ominous mutterings about leading a "simpler life" with "less stuff", and also the cost of transporting "a load of junk" across to the other side of the world. It does not take a genius to work out where this is heading... (I have ~4 engines and two bikes in boxes).

I am working on finishing fiddling with the frame so I can get it painted. To this end I have installed the engine/carbs/filters/clipons/cabling etc etc - to work out if I need to add or remove mounting points to/from the frame.

I am committed to moving the oil tank and junking the airbox. Aim is to get an empty middle section. I considered many options including:

• cutting the tank up (see above)
  
• oil in frame and tank near headstock - I concluded that this would not work as the tank would be lower than the frame rail
• tank under seat hump - still a possibility
• tank fuel tank/seat - current favourite

I have done a lot of reasearch but can't find photographic evidence of what other people have done, other than a single shot of a Dutch (?) guy's bike at a thumper meet.

I have mocked up an oil tank in cardboard (see below), however it does not make full use of the available space. Capacity is good at 2.4lt (original is 2.2lt). My concern with this is that it's long and flat - if the pickup was at the front of the bike I would be worried about starvation under accelleration.

I also made a mockup in SolidWorks. Capacity is 2lt (which I think is OK). There would be a 1cm gap between the oil tank and fuel tank, which I would fill with ceramic wool insulation or similar. It is less long than the cardboard mockup which should reduce starvation issues. I would add an internal baffle to help with this too.

Remaining questions then: where to route the oil feed and return lines? They will be difficult to hide without putting serpentine bends to try and follow the frame rail. I am OK to do this (have pipe benders) but coincerned about the effect on flow... May still do but what do you think of the routing below?

Final pipes will be 10mm solid, so not big fat braided jobbies or anything. I did want to keep this volume clear of pipes, but also I need to make some progress on this project! What do you think? Am going to weld it up out of 1mm steel.


Return pipe routing


Flow pipe routing


Cardboard mockup


Solidworks mockup

[guest1972]

...oh and yes, the starter motor is going...

Links to any similar projects appreciated.

[Steve Lake]

well, if you had a later monoshock engine, they had the oil tank in front of the motor, with the header pipes swept to one side and siamesed underneath, a nice touch.
this would save you having to reinvent the wheel , so to speak....
but I'm always wise after the event !

good luck with it

if SWMBO prevails ... there's a good home waiting for 'junk' in Norfolk 

[Steve Lake]

those CR's look the biz don't they