82 GPz750 keepin' it real,.. for now

It's only supposed to be about a year or so old. I wasn't really worried about the charging system I just wanted to check it.

If you buy a chain don't buy it on eBay unless it's Japanese and new. There are cheap chains there and can kill you if they fail. Parts angel is one of them. Made in China. He doesn't tell you that and the one I bought came apart. I caught it in time.
Steve

I'll keep that in mind. We have several good independent parts houses and a couple of Kawi dealers here so it shouldn't be an issue.

After the wreck in 86 I bought a 550 that looked like that for $500. That thing really moved. It gave me the bug again so I got Bossie back on the road. Good for the soul. :woohoo:
Steve

I just came from the garage, It's getting more real

I went and rented a compression tester, The best number I got was 90psi on #4, the worst was zilch on #3. This was before I checked the valve clearance, however, I only had two valves that had any clearance at all #2 exhaust @ 0.0015"/.04 mm and the only one in tolerance #3 exhaust @ 0.003"/.08 mm.

I stopped there since wasn't sure what I should do next. Should I get a set of shims, set the clearances and run a check again? Can I just pull the shims, put the cams back on then run a test to see if my numbers get better? Or should I just pull the head and cylinder block and take them in for machining?

It was a bit of a let down. I'm not entirely surprised though, I knew this scooter had issues but I was hoping it wasn't this bad, I guess my hopes of doing some canyon weaving are capoot for this season.

Don't despair. If the valves have no clearance they are being help open some. Given that, it is normal for the cylinder to not hold compression. I would take care of getting the valve clearances correct before worrying about compression. You may find that is all that's needed. Ed

DO NOT TAKE OUT THE SHIMS AND TURN THE ENGINE OVER.
Do get a shim kit for your motorcycle. Compared to ours, it's cheap. Get them set and see if the compression comes up. Chances are it will and get better as time goes on. I'm sure there some that think I harp on valve adjustments too much. Maybe so. This is why.
Steve

If you guys really think it's worth a shot I'll do it. I'm really stressing that its been so long since they've been adjusted the valves and seats are toast.

I've been hunting around for the kits but cant figure out what diameter I need. How about a good durable valve cover gasket since if this works I'll be checking it pretty regularly to see if things tighten up.

EDIT: OK I think it takes a 13 mm shim, does that sound right?

If you don't hear any chirping you might be OK.
Steve

Yup, 13mm shims, from 2.00 to 3.20 mm...same as the all the four cylinder 8 valvers from 400,500,550,650,700,750cc.

With clearances all over the place I'd re-shim, then put some miles on it and then retest. Also even if you have piston and bore problems you will get a sense of the amount of wear on the valves and seats according to how thin you need to re-shim to get your clearance.

Often If the bike has been standing unused for years the one pots with the open exhaust valve rusts the bore internally . If the problem is just one pot stuffed you could try pressing it out and put a replacement liner and piston in as an alternative to going oversize on all four.

My 750R was badly down on one pot, dry test about 50 psi. I'll check it again within the next few days after 1000 miles running really nicely and I'm hoping it was gummed rings on that pot. These are nicely powerful motors and assuming it isn't rattling bad and drinking oil then even if you are a bit down on power it will suffice for communting for now.

Thanks guys! Are the Hot Cam shims ok?

A bit of progress, Token progress as it might be. I stated earlier that I didn't like the square headlight. So while surfing eBay I found a killer deal on a nearly complete Spectre headlight assembly, I got it today so I ran out to the garage and mounted it up ASAP. I think it looks pretty good. I'll go through the wires after I get my instrument cluster in and make sure everything is back where it's supposed to be. I do think I m going to flip around and invert the headlight mounts on the forks so it sits just a bit lower. The aiming brackets don't match so I'll have to find a remedy for that as well.