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Re: '75 cb550 and '71 cb175 double build!
What makes you think it was put together improperly? Something out of place other than the hardened gaskets?
No sealant was used on my base or head gasket. Didn't think it should be used. Was the head torqued down when you got it?
jag767 said:Well here's an strange update.
So out of curiosity I rechecked the compression. 130. And there's my issue. So last night the engine came out, and I tore into it. Now I was told the motor had never been messed with. HA! What a lump of crap. First thing I notice is all the gaksets, no adhesive on them. They literally were just kind of there, and we're so hardened I thought they were metal for a second. Next thing to jump out was the big Ole .25 on both pistons. So my conclusion is someone in the past rebuilt at least the top end of the motor.
Here's my question, can poorly sealing gaskets, including the head gasket, cause that low of compression and a shitty idle?
I know it can cause issues, but we're talking like -50 psi compression and a motor that's hard to kick over, with an erratic idle, that stalls within a minute. The pistons and rings look like maybe there's 500 miles on them, so the only thing I haven't measured up is the valves, which if I can avoid taking apart I'd like to.
I'm taking it to have helicoils put in for the spark plugs today, and was going to do a 1 mm overbore as well as have it decked. Now I'm thinking just do the helicoils and put it back together properly.
Thoughts?
What makes you think it was put together improperly? Something out of place other than the hardened gaskets?
No sealant was used on my base or head gasket. Didn't think it should be used. Was the head torqued down when you got it?