1988 bike



  • I have eventually got round to stripping bike ready for rebuild, lots wrong, swingarm bearings u/s, head bearings u/s, rebore, etc. Numbers match though and will be rebuilding as original as possible. Has 3mb barrel and 3bn head, already bored out 1.75 so could get interesting/expensive. Missing a lot of bits though (footpegs, handrail, indicators, instruments etc) but have already bought all new bodywork Inc nos tank and various other bits. Will post up some pics as I progress but if you have any original nuts/bolts you want to get rid of give me a PM, in particular fork headstock clamp bolts and similar, powervalve Bush engine left side..Also yellow disc guard (I know, rocking horse poo)
    Ta



  • Hey long time no post!

    Look forward to seeing how you progress with this one!!!

    Welcome back 😃



  • Being a 88 won't it have the longer stroke crank? With that and oversized 3mb barrel probably gained quite a few cc's



  • Been a busy time, was hoping to do over the winter but no time for enjoyment, have to take time off for other reasons so here we go! Was hoping that there would be less to do but no chance! Be good to have one of the earliest ones in original condition, my red 88 had an engine and electrics transplant in 91 so not quite genuine.



  • @DTR-NSR
    Its going to be all original with the exception of the operating power valve, has the original round slide carb. Will make other improvements only if its unseen, have a spare mikuni power jet carb but not changing spec. Rebore will take it up a little but have been told this is the last (safely) that can be done which is a shame as it will be used and not a show pony, although mileage will be limited (too many toys). Cases being blasted as whole engine has been sprayed as an assembled unit, the rest I can deal with at home.
    Sorting bits for replating this week that I do have, don't think my usual supplier can do olive drab though. Got a list as long as your arm for spares needed so may have to sell another kidney!



  • Frame gone to have the powder coating done again, damaged in storage unfortunately. Swingarm bearings hard to remove, powdercoated with bearings in place previously and proving a nuisance to remove. Bush in bottom of shock u/s of anyone knows where to source a new one? Fowlers?
    Need spring compressors so that can be redone as well. Stripped off barrel and a lot of oil in cases though big end seems good, full rebuild coming up.



  • @oldman could I ask why spray engine a assembled unit when you crack a bolt it will crack the paint



  • You will have to ask the person who did it, will be reassembled properly with metal cases and refinished side covers in dark grey metallic 2 pack



  • @oldman Have a look on simply bearings for that bush if you can measure it?



  • @Calum will do Calum, left to soak in release spray as bolt seized solid but will measure when it comes out. Had a sort though of bits and need to find a helmet lock, last ones came from the States. Have another nearly new speedo though with 320 miles on it, just sorting in to piles for plating at the moment.
    Ta



  • Have actually managed to find a second hand mb barrel with more life In it, just waiting for it to arrive, cylinder head cleaned and powervalve cleaned and polished. Loads of bits came from fowlers in prep for rebuild. Need overflow hose from rad to expansion bottle if anyone has one lying around (discontinued). Helmet lock ordered from Japan, genuine Yamaha ignition lock changed to 4 wire plug and earth, carb stripped and cleaned, waiting for frame to come back and frame parts I have ordered ordered to arrive from France and them can get those powdercoated and plated.



  • Removed swingarm bearings so that's ready to go for refurb, and finally removed rear shock lower bolt. Removed seals and found worn ball joint that seems to be pressed in to shock lower. Any advice if repairable or should I be looking for another rear shock?20190528_234455-512x288.jpg



  • My mistake, ball joint held I by 2 spring clips in recess of shock lower. Saw them when I enlarged pic posted. Have got the 2 clips out , heavily corroded, ball joint stuck fast. Left soaking on release spray, but still left with trying to find replacement unless find a nush that fits?



  • @oldman they are not serviable as far as I am awake.



  • @Calum said in 1988 bike:

    @oldman they are not serviable as far as I am awake.

    Thanks Calum, ordered one from Portugal (second hand) that looks good without rust for a reasonable price. Other 3bn barrel arrived today freshly rebored @1.25 over standard, and has been tuned. No id marks to say who did it , messaged seller to see if he knows. Mick Abbey marks his work as far as I am aware so doubt its him. Be good to know though and a bonus it's done. Will post a pic up later.



  • 20190529_181638-512x288.jpg 20190529_181645-288x512.jpg



  • @oldman What engine are you fitting this to?

    3MB barrels and 3BN barrels are not interchangable!

    The 3BN has a larger bore, therefore shorter stroke. If you fit this onto an engine designed to have a 3MB cylinder, you could risk the piston hitting the cylinder head.

    It is very minimal, but they are different strokes.



  • @Calum it's the 88 bike engine, same as the barrel that came off, 89 bikes changed to accommodate new carb amongst other things, is that right? Matching frame and engine nos so original engine



  • By the way, I mean the 88 bike I am building (endurance blue), not the red one.



  • @oldman So the original barrel was a 3BN. I have only seen them on the 88's. You would just want to double up on the base gasket is all, I'd expect.


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