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I parked Succubus, my original '79 Standard, two years ago. It was a real problem child. Ran like the wind, would not idle on No. 1. I have eight running motorcycles. I figured I would get back to it whenever I stumbled upon a Round Tuit.
Well, I found one and went back to look at it. I tested the compression today and I am a bit perplexed. The bike has new rings with like, maybe, 300 miles on them. These are one step OS rings filed down to fit a stock cylinder. Before I parked the bike (ok, it was more of an on-site banishment) I tested the compression. I don't remember the numbers exactly, but I remember I had good, equivalent compression on 2,3 and 4 - seems like it was around 145-150 - but low compression on No. 1 - like maybe 100. That seemed like the reason I couldn't get No. 1 to fire at idle and I didn't feel like tearing down the top end again.
I checked the compression this morning, during a brief hiatus while my starter button actually worked. Now I have little to no compression on No. 3, low compression on No. 4 (about 75) good compression on No. 2 (about 150). No. 1, however, has enjoyed a renaissance. The compression is really, really high - like about 180.
I can explain, in my own mind, why compression would drop after a long layoff. I'm figuring stuck rings. Can anyone explain, though, why No. 1 compression is suddenly so high?
I still don't want to tear down the top end without cause.
Patrick
Well, I found one and went back to look at it. I tested the compression today and I am a bit perplexed. The bike has new rings with like, maybe, 300 miles on them. These are one step OS rings filed down to fit a stock cylinder. Before I parked the bike (ok, it was more of an on-site banishment) I tested the compression. I don't remember the numbers exactly, but I remember I had good, equivalent compression on 2,3 and 4 - seems like it was around 145-150 - but low compression on No. 1 - like maybe 100. That seemed like the reason I couldn't get No. 1 to fire at idle and I didn't feel like tearing down the top end again.
I checked the compression this morning, during a brief hiatus while my starter button actually worked. Now I have little to no compression on No. 3, low compression on No. 4 (about 75) good compression on No. 2 (about 150). No. 1, however, has enjoyed a renaissance. The compression is really, really high - like about 180.
I can explain, in my own mind, why compression would drop after a long layoff. I'm figuring stuck rings. Can anyone explain, though, why No. 1 compression is suddenly so high?
I still don't want to tear down the top end without cause.
Patrick
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