Timing belts

[firstgen513]

I just bought a 1981 GL1100, it runs however the compression is low on the number 2 and 4 cylinders (90 psi) the previous owner said he just replaced the timing belts. Would having that belt off a tooth cause the lower compression? My next step is to check the valve clerance.

Any thoughts would be great..

Thanks,

[Right Winger]

I would say so beacuse the timing belts control the valve timing inturn directly affects compression. If your valve timing is of it will affect compression.

[raycw]

Timing belt(s) being out of time will effect the compression but you're thought about checking the valve clearance is 'spot on'. Check the cam belts AND check the valve clearance. Hopefully you'll find the problem there.

[firstgen513]

Timing and valve clearance were OK. The cars are way out of sync. I only had a cheap vacuum gage with no 5mm adapter. I got them close and it does run a lot better. The fuel smelled real old so I stuck some SeaFoam in the tank as well and oil as well. It will least pull its on weight now. I guess I will take in in and have the carbs sync'd.

What can I expect to pay for that?

[Right Winger]

Good glad your getting closer but if you have bad gas I would atleast drain and refill with fresh gas before you have carb sync done . I could make a big difference in the outcome afterwards. See if you can run a fresh tank through first maybe with your seafoam. Just a suggestion

[RBGERSON]

sounds like it's been sitting a while..synching only effects the bike at idle not on the road..for what you'll pay to have it synch... buy some gauges and adapters and do it yourself..if you don't have a source I do for adapters..$10 for 4..gauges at HF for $10 each so for $30 you can have your own synch set up. Note running the bike for a couple of hundred miles will loosen up the rings if they are stuck and compression will come up..if it's a ring problem. easy check is to put a little oil in each cylinder and redo the check if compression comes up it's a ring issue if not valve issue or worse..cracked something, headgasket, etc.

Also running a little sea foam/MMO/kerosene in the oil for 100 miles lightly..will clean out the engine gunk..something to do before every or every other oil change.