compression

Hello all,its been a while but Im hoping to share some of the details this project, listing out what i can (my brain likes this method) and taking some hopefully decipherable photos. So far: Compression @ 140 / 135 - seems pretty low to me, I have these readings pre-tear down and ordered some...

Hi Everyone, I'm new to this site (actually to the whole "forum" thing entirely!) but I've been having trouble with my bike and would gladly take all the help I can get! So a little history: In a previous buy I got two yamaha xs400's (1977 and 1978 I think). The 77 had a title so I used that...

First post! Been using this forum for a couple months while restoring my FIRST bike - 1981 xs400 HE. She's teasing me guys. Cold start is great but after short test drives, getting up to speed and downshifting, dies EVERY time and will not start electronically or by kick. Floods, drains...

Hi folks, Not been here in awhile. My efforts on the XS are a bit sporadic as I keep striking issues with getting it going. Now, I happen to have a set of NOS standard size barrels for my 79 XS400F. I was hoping to find new std pistons but they don't seem to exist in the 'A' variant I need...

Hey, Changed my oil and adjusted valve clearances yesterday, now valves all within spec. Took a video before right cylinder intake valve was set properly. Didnt like the sound so went back over and checked all clearances. I just did a poor job on one of them (was .003 out! on an intake valve...

ok ok! To satisfy all of you curious cats, I am finally posting pictures of my J. Believe it or not, it looked much worse than this but running ok when I bought it. Now, It runs fantastic! But still looks like a crippled dogs ass. I was at a local shop the other day oogling over some customs...

I performed a dry/wet compression test. Here are the PSI measures: Left | Right --------------------- Dry | 105 | 100 --------------------- Wet | 155 | 155 The wet test was performed by adding about 3-Tablespoons of motor oil into the spark plug holes just prior to...

ya so im doing this buil... got it all back together.... got gas.. and trying to fire it up... wont kick over it has spark on both sides .. i checked compression and its only at 30psi.... before the build it was 150!!!