onelifeonelove43
Been Around the Block
1970 cb350 twin, starts one kick and idles great. No smoke or back fires but both cylinders are at 90psi, any thoughts on how to fix/improve without tearing into the top end? Valve adj? Thanks!
cb350 twin compression question
- Thread starter onelifeonelove43
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onelifeonelove43
Been Around the Block
Thanks, I'll try to get them timed better, just in cSe, could the valves or carbs also be the problem?
has it sat for a while? If so you might just try riding it for a while adjust the valves etc. and then see if the compression gets better. if you have a timing light check the timing, but it should be good unless you or the p/ o did a tear-down, or its got some miles on it and the chain stretched. My theory behind riding it, if it is a bike that sat awhile is that there could be a slight bit of rust or carbon keeping it from seating perfectly. with use this may wear off.
I have three cb360s I tested all three for compression, the one that ran the best had the lowest compression the one that ran the worst the highest.
I have three cb360s I tested all three for compression, the one that ran the best had the lowest compression the one that ran the worst the highest.
When PJ refers to timing in this case he's talking valve timing and that implies the cam chain is extremely stretched or the motor was rebuilt with the cam on tooth out out of place. To check and/or correct that, the top cover has to be removed to see the cam position relative to crank position.
What is the history of the bike?
Was the compression check done with throttles and chokes wide open? If not, repeat.
Did you check compression on any other motor with that gauge and do you know it to be reasonably accurate and repeatable?
What is the history of the bike?
Was the compression check done with throttles and chokes wide open? If not, repeat.
Did you check compression on any other motor with that gauge and do you know it to be reasonably accurate and repeatable?
onelifeonelove43
Been Around the Block
Thanks guys, when i tested the compression, i did it with one plug in, ignition off, plug wires off and throttle open, kicking it several times, both came out to 90-93 almost dead on with each other.
As far as the history, you guys would probably know more than i, cheap craigslist find. I doesnt have matching motor/frame numbers, the odo read about 18000, but actual milage?
When i squirted some oil down into the plug holes, the left went up to the 120 and the right went up a bit, maybe 105. i dont know what else i could be leaving out, will it damage anything if i go ahead and ride it, and try and break it in as mentioned above before i do/get (undecided) a valve adjustment?
Thanks -Logan
As far as the history, you guys would probably know more than i, cheap craigslist find. I doesnt have matching motor/frame numbers, the odo read about 18000, but actual milage?
When i squirted some oil down into the plug holes, the left went up to the 120 and the right went up a bit, maybe 105. i dont know what else i could be leaving out, will it damage anything if i go ahead and ride it, and try and break it in as mentioned above before i do/get (undecided) a valve adjustment?
Thanks -Logan
