Opening this question to all. I've got a '90 FLHS, and I'm going to be doing a compression test on her.

16K miles, engine is in good shape, so I'm curious. What should I be looking for numbers?

Thanks in advance!

 

Do you have a stock cam in it? If so, 140 per cylinder would be a great number.

 

Jake, as far as I"m aware, the motor's stock (I know I haven't done anything to it, but I've only had the bike 4 months). Just seem's strange to me that I asked the dealer to do a test recently, and they came back telling me that front/rear was 215 PSI and then bragged how that was "textbook perfect".

I may have larger cams in it, but there's really no way for me to tell without ripping her apart, and I'm not ready for that.

I've opened this question up to alot of folks, and I seem to get back similar numbers... so now I'm confused.

I'm going to do a test myself to see if the reading they gave me is even remotely close.

Thanks!

 

Factory manual says minimum is 90psi, which seems pretty low!

I had to stop by as I also have a 1990 FLHS, which I bought new. A bit modified now as you can see.

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