compression

Yamaha Star V-Max VMAX Motorcycle Discussion Forum

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  1. D

    Banging my head over here

    Hello, everyone! Jon, here, again! I'll just get right to it. Back in November my 2007 Vmax was having some starting issues and I went back to school after the holidays so I didn't have more than a few hours a month to work on her. Summer is here, so I've got some free time. I have done as...
  2. davidon

    Compression tester

    Need a tester. Can anyone loan one out or if not what is a decent brand to get?
  3. U

    Wired compression test

    Wired compression test Hello all, I a few days ago I got my new vmax from USA This is a 1985 vmax with 18,800 miles I perform a compassion test and got reading that I do not understand: The two rear cylinder (number 1 and 3) had both a 196 psi while the front cylinders (2 and 4...
  4. Y

    Low engine compression.

    I was changing out my sparkplugs today and decided to check my compression while I was at it. The numbers I got seem pretty low, 125-130psi. This is 97 vmax with 29k miles. The minimum according to the manual I have is 170psi. Wondering what I can expect on an engine with this mileage, any...
  5. A

    Compression spring and washer?

    Went to change the oil on my 93 vmax and the compression spring and washer wasn't on there. Are these nessesary on the oil filter? And was thinking of doing the oil filter conversion kit. Has anyone done this? Thanks.
  6. rdbul

    Low Compression in Cylinder 1

    I have an 89' Max with 22,000 miles on it, Pods, Stage 7, and Cobra exhaust but otherwise stock. The last time I rode it developed a exhaust thump, the regularity of which had me thinking it was a single cylinder issue. Did shotgun, no improvement. Pulled plugs, verified spark, and compression...
  7. V

    Carbon Build up and Compression

    I finally got around to sticking a compression gage on my MAX and results weren't too bad, but not great. The good news it I don't think I have any leaks and I'm still within the recommended range, pretty good for a 20 yo motor. I am however at the top of the safe range, around 170 on each...
  8. R

    Blue smoke om WoT and strange compression readings

    Hi, One of my fellow riders told me I am leaving behind blue smoke when I accelerate hard so this winter, I`m planning to fix that. First things that come to mind are the valve seals, my bike had been standing for 10 years when I bought it so they might have dried out but to verify I did a cold...
  9. Irtron

    Low compression + grey smoke

    Hi everybody. I have a 1994 vmax with 35000 miles on the clock that suggests it's time for some maintenance I bought the bike last autumn as you can tell from my vmf join date. Immediately I noticed greyish smoke from the exhaust when I rev up after a bit of idling at traffic light or warming...
  10. D

    Leakdown and compression

    Is it possible to do a leak down test that shows less than 4% loss, and still have top end issues? My leak tester is reading 88 psi in and 86 psi out on all cylinders. Cylinder 3 plug looks rich, but not soaked, and I'm getting 20mpg. I'm very concerned about gas washing that cylinder and am...
  11. D

    The saga continues-compression done/plug pics

    Before I start... 5300 miles on bike. Sat from '05-'11, when I bought it. It was obviously under a tree or something for a lot of that time. I've been getting 20 mpg for all three tanks of fuel I've put through my max.... I know that's not right. Everything seems to run smoothly, but I don't...
  12. V

    Compression Test Mis-Information

    My Yamaha manual lists compression test results in the "Periodic Maint." section should be "Standard 142- Minimum 128- Maximum 171" But in the back of the manual it lists compression pressure as 206. But my clymers says medium is about 200. My bike is a 2001. Also what are the valve lash values...
  13. SpecOps13

    Nagging Compression Ratio ? From PSI Reading???

    I've been asked what the Compression ratio is on my 89 Max. I searched the web for an answer to the question of PSI Reading on the cylinders vs actual compression ratio. Best answer I came up with is the compression reading divided by 14.7. Stock Vmax's have a 10.5:1 compression ratio. My 94...
  14. SpecOps13

    SkullDuggery, Compression Retest

    In the original check of my 89, months ago. The cylinders measured 220-230 (My 94 was 150-160). I've been looking for a second gauge set up to do a retest of comparison. I found one yesterday with the proper 12 mm adapter. Although the resulting numbers are somewhat lower than my original...
  15. thundermax

    Cylinder Compression Test

    Checked compression with warm engine, wide open throttle, all came in at around 120 psi. Bike runs strong but this PSI seems low. Is it? Is a 98 with 10k miles. Is this telling me I need a valve/lifter adjustment? Thanks.
  16. Rusty McNeil

    Interesting Reading on Compression Ratio

    Ran across this today, thought it was pretty interesting.... Especially in how static CR isn't what you end up and how it also depends on the Cam etc as well, something I knew but never had explained this well...
  17. VMAX1260

    Question for high compression pistons and turbo charger

    Does anybody know if i can install a turbo charger in my v-max which has carrilo rods and je pistons high compression. If i put a gasket so i will reduce the pistons copression will it work.????
  18. bikedave99

    Low Compression (Bad rings or valves?)

    Well, I went for a ride on Saturday for a bit and came back and had bunch of oil on my engine. Not the typical seeping oil but splashes. It looked like it was coming from my airbox so I figured it was leaking from the carb joint which goes through the airbox. I was right, one joint was loose and...
  19. rebar

    Leakdown , compression , or both?

    Im looking at buying a used 85 vmax and want to check out the engine as well as I can. Im pretty sure I know how to do a compression check but not sure on the leak down or if I need to do it. Which test should I do? And does anyone have a link which discribes both or the leak down test...
  20. rhoke

    No Compression HELP

    Hi everyone. I have a serious issue might be a first for some of you as it definitely is for me. I just rebuilt my entire motor split cases and all so new bearings and the whole deal. I had to set the crank using the #1 tdc and water pump window for the balancer, as my engine did not have the...
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