OK, looks like i have a project to get done, my CB bearings finnaly went, and looks like valves are getting abit too snug. so tues, wed, and fri, i will be attempting to remove the engine,remove the lower casing, replace the bearings with some used stuff i have (im flat broke, cant even afford gaskets but i have some sheet to cut some) and get it all back together and running before Fri.  lets see Tues is moms Birthday. wed is Inlaws Dinner before they leave town, and Thurs and christmas IE all the rest of Family that came INTO town. Fri back to work.  OY!!!!      I will TRY, but can not promise, to snap pic's of the basic tear down and Half Assed refit/bandaide of the bottom end (attempting to Not remove the topend)  i have been trying to "get By" till i have Incometax return cash inhand, then i could rebuild the 1 extra complete engine, and the 3 extra Bottom ends having them ready for swap outs. but it didnt hold out.  I dont even have a Damn book for torque specs,valve clearence specs, or bearing clearence specs.  Wish me luck folks, this is the ONLY working leagel transpo left in my household.  Car Insurence must wait untill incometax comes in.

If all bearing shells were the same from the factory, I'd say you could get away with a band-aid approach.  There's an excellent possibility that in the manufacturing process that different bearing shells are used, in order to compensate for slight variations in crank diameter.  I wouldn't attempt to tackle a project such as this without some plastigage to confirm clearances, and torque specs (which I or anybody with a decent manual can provide).  You stand to do more damage than good, trashing an otherwise good crank and/or cases in a few short miles.

I found 2 flaws when i opened it up. 1 counter ballence shaft was hammered, but athe bearing shell wasnt warn through or spun like i expected. but the CB shaft near the drive gear seem to have warn through only on half the shaft.  changed the bearing shells, and used another CB from another  parts engine.  went together well enough, aside from snaping 2 of the smaller diameter case bolts while torquing. no i didnt open it up again, hopefully it will hold together for 2 months while i prep another bottom end. Then when income tax check comes Via rapid refund. i will build the others with fresh bearings,seals,Rings ect ect. how Badly would performance suffer if 450 cyl and pistons were used on 500 with 500 heads?.  


Now, i talked to prev Owner about some of the specs before cracking the cases open, he recomended plugging the oil holes and ditching he CB shaft as a temp fix till another engine was built,  he claimed when racing it would break motor mounts, but on the street it wasnt bad, just use thick grips on the handle bars.  Is there any truth to this? is the vibration un barable for a stock engine on the street? i understand the bigger bores more power/weight tossing the harmonics around pretty bad.

Quotehow Badly would performance suffer if 450 cyl and pistons were used on 500 with 500 heads?

You're only talking about a 40cc difference and some if not all of that loss can be regained by upping the compression ratio when you scoop out the combustion chamber (required for this interchange of parts).  It'll take some math plus the heads can't be re-used on the 500 afterwards.

Quotehe recomended plugging the oil holes and ditching he CB shaft

The GS has been described as "un-ride-able" sans balancer.  Maybe it's not so bad in the lower rpm's.

Too bad about those broken bolts.  I would've cursed up a storm.  I'd leave it for a day or two but would fix it before throwing the bike back together.  I can't enjoy the ride if I've done a shoddy repair.

Im past the enjoyable time, im under time crunch, this is my only transpo to work. if it holds for 2 months, i sould have my Incometax return and hence parts to rebuild a comeplete other motor.  im now im hoping to get by.

Well its together and running, Ofcoarse the 2 bolts i snaped putting it together leak oil but its holding.  now i dont remember, but seems abit more buzzy then just before the CB bearing went. once it reachs about 5k rpms it seems to vibrate abit under load,  free rev it feels fine. im wondering if i dont have the CB shaft one tooth off.   then again im sure real clipons transfer the vibs better then the rubber spaced bars.  Any how, being as im still alittle paranoid that it might not hold, im going tostart preping the other Bottom ends i have. and after talking to Prev Owner and other friend who had and raced GS's they both pulled the CB shafts and ballenced the Cranks, Larry ran a 555 kit in his with ballenced crank and said it was ok for street the power and rev diffrence that came with it was worth the comfort tax. Garry (the prev owner of this bike) claimed to have run both Ballenced and un ballenced cranks with no CB, again the revs improved to the point that it was like a new motor. the long sessions of track time in the higher R's vibed so bad the mounts broke on the frame. but the ballenced crank it was merely 2 stroke buzzy, thicker padding on the seat and slightly thicker grips were all that was needed to fix that. so, now. im considering preping one bottom end just like that.  the upside is No CB shaft to ruin a case. the cranks can live along time even while being flogged where as the CB cant. the Crank isnt swinging 2x its own mass therefor the revs will pick up considerably.  the downside, More Vibration/buzz and the cost of ballencing the crank.


I am in need of TOP end stuff, i need 2 sets of stock pistons and 1 head. if you have these things and want to be rid of them cheap cheap, let me know.