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  1. S

    Good compression, but really bad leak-down test?

    Thanks. :) I found out they are called N102.221. So I will try to order PAJ1 - 90, and PAJ2 170 so I'm sure it's the right one. I tried to replace PAJ2 with Mikuni 150, but that didn't help. It still spitting through the carburetor and it hesitated in the middle range. The covers are in...
  2. S

    Good compression, but really bad leak-down test?

    What I can find by searching here on the forum, the bike is born with PAJ1 - #90, and PAJ2 - #170 If I measure the hole in my PAJ2, then it is about 1.85mm even though there is stamped 170 on the jet. Does anyone Are there any who knows if the hole should be 1.70mm when 170 is stamped on the...
  3. S

    Good compression, but really bad leak-down test?

    Do you mean these o-rings in the yellow circle? They are "unfortunately" in good condition There are no holes in them and they look fine. But here in Denmark where there are only 32-40℉ at the moment, they are a bit stiff. Three of them are slightly thicker/stiffer rubber and the fourth is...
  4. S

    Good compression, but really bad leak-down test?

    Now I had time to look a little more at the motorcycle, and it is a happy update. :D if sdt354 had not mentioned that i had to do leak-down test in compression stroke (which I have overlooked since this is the first time i try to do leak-down test), then i would probably have ended up...
  5. S

    Good compression, but really bad leak-down test?

    If the piston is not 100% in TDC, then it will skip a stroke as soon as I add air. And it's clear to hear if it does. So it is not necessary to keep the engine locked if you have got the piston 100% in TDC :) I must admit that I have not noticed whether it was compression stroke or the...
  6. S

    Good compression, but really bad leak-down test?

    Yes I turn the piston in tdc on the cylinder I leak-down test.
  7. S

    Good compression, but really bad leak-down test?

    SpecOps13: Yes the heads torqued correctly, and in the right order. I will check timing when I get the opportunity next week. But I'm 99% sure it is right. I will take some pictures/videos next week. sdt354 I actually made compression and leak-down test three times to be sure, and every time...
  8. S

    Good compression, but really bad leak-down test?

    Yes sorry I forgot to write. Compression test and leak-down test were made when it was operating temperature :-)
  9. S

    Good compression, but really bad leak-down test?

    When I do leak-down, I can clearly feel/hear the air in the intake and exhaust. So my guess is the air passing the valves... But they should be properly-seated/sealed after the workshop has rebuild them. But maybe they have done a bad job. I just don't understand why there is such good...
  10. S

    Good compression, but really bad leak-down test?

    Hi everyone. I bought a Yamaha vmax 1200 from 1992 which was hard to start and when it started it was 4000rpm idle. (It was bad o-rings at the intake manifold which is fixed now). I did a compression and leak-down test that showed. Cylinder 1 -180psi (under 10%) Cylinder 2 - 25ps (Aorund 30%...
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