1982 GS850G Maintenance questions

[quentinnash]

Recently bought a 1982 GS850G that looks like it has had a hard life. Over 40,000 miles, clearly been dropped at least once and just generally in need of TLC. The bike starts and runs okay, clutch breaks away at 5000ish rpms and the petcock leaks gas. When I got it home I drained all the fluids,(crankcase oil, gearbox oil, and final drive oil) and put new oil and gear oil in the respective places. Test drove it and it ran okay, clutch still gave under heavy load and it sounds almost like a timing chain rattle at idle.

I've been creeping here and reading bikecliffs site like a bible. Today I rebuilt the timing chain tensioner(leaking oil), pulled off the carbs and boots to check the o-rings on the intake boots and they were surprisingly in good shape. Still round and springy. I pulled the gas tank off and rebuilt the petcock and modified(per bikecliff's site) the fuel level sender because it didn't work. Went into the clutch basket and found the friction plates within spec, but several plates were blued and slightly warped and the springs were out of specs. I replaced 4 of the steel plates(OEM Suzuki) and replaced 3 of the worst friction plates with new suzuki plates and installed KG heavy duty clutch springs. Feels way better at the lever, but I haven't been able to test ride due to valve clearances.

Which brings me to my questions. I downloaded the worksheet to check the valves and started checking them slowly and methodically. On all the intake valves I can NOT get my thinnest gauge( .0015in/.038mm) to go in, but all the buckets still spin with finger pressure. I can fit my .0015in gauge in all the exhaust valves, but not a .002in gauge.

Shim sizes are as follows:
Cyl #1: ex 2.90; in 2.60x
Cyl #2: ex 2.90; in 2.65
Cyl #3: ex 2.65; in 2.75x(numbers worn off but checked with a caliper)
Cyl #4: ex 2.65; in 2.65

So I know I need to get some thinner shims, but I'm not sure if I need to drop the intake shims 1 or 2 sizes. I am not sure where to get shims, I live in northwestern bumf**k Georgia and I don't really trust the bike shops around here. I am hoping some of the mighty gurus here can point in the right direction.

Thanks,
Q

 

[tom203]

You've been busy! Consider joining the shim club here to get your shims. Send a PM (personal message) to member "ghostgs1" for explanation. It's ok to run with more clearance, so aim for thinner shims as clearance gets less with running over time.

when you reinstalled the camchain tensioner, did you remember to back off the screw (to let the plunger slide out)? This is a simple device that often gets installed wrong.

 

[quentinnash]

Thanks, I'll send a PM to ghostgs1. Good looking out on the tensioner lock screw, I made sure the plunger popped out and then backed the lock screw out 1/2 turn and tightened the lock-nut while holding the set screw.

 

[tom203]

Thanks, I'll send a PM to ghostgs1. Good looking out on the tensioner lock screw, I made sure the plunger popped out and then backed the lock screw out 1/2 turn and tightened the lock-nut while holding the set screw.

Sounds good! As to petcock, rebuilding is an iffy art, so be wary. New made in japan equivalents can be had for about $60 like this florida guy....
http://www.georgefixs.com/brand-new...s550-gs650-gs750-gs850-gs1000-gs1100-petcock/

 

[Nessism]

Z1 Enterprise sells shims. I suggest purchasing enough of the right sizes to move each valve two steps. You may not need them immediately but you will need them in due time so you may as well stock up.

BTW there is no issue with moving the clearance up to .10mm or even higher. Big KZ bikes, which the GS engine is based off of, run clearances up to .15mm so you can use that as a baseline.