torkyolds
Newbie
Hello all,
I am helping a friend out and checking out his phazer. He said it has been gradually losing power and idles rough. Unfortunately, the snow has melted around here so I can't really work it.
I did a compression test, normally I'd say it's really low at 50 -65 psi- prob 10 puffs, until the gauge settled. But these have a decompression system that fails? I've seen on here should be 200 psi wet test?? I'm nowhere near that! Wet test gives me 100-110. 65 dry seems awefully low considering it starts well. My compression gauge is a good quality snap on that has never led me astray. Doesn't use oil, but call me crazy, I see a tiny bit of man glitter on the oil dipstick?? May need to cut open the oil filter and unfold the media as I do on my car race engines.
Just think this is wierd, I thought the yamys were bulletproof plus this only has 8000kms on it. However, we don't know the hist as my friend bought it used at the begining of the winter. I also measured the resistance of the coils while I had it apart, primary should be 1.2-1.6ohms? I had 3.2 ohms. I would throw coils and plugs at it, but that's not going to help compression...
This is a dirt bag to work on, everything miserably buried.
I miss my old sxr 700 red head!
Interested in your thoughts.
Thank you
edit: can't give a % leakdown as my tester is at work, but did put air in cyliders at tdc and didn't hear any obvious
I am helping a friend out and checking out his phazer. He said it has been gradually losing power and idles rough. Unfortunately, the snow has melted around here so I can't really work it.
I did a compression test, normally I'd say it's really low at 50 -65 psi- prob 10 puffs, until the gauge settled. But these have a decompression system that fails? I've seen on here should be 200 psi wet test?? I'm nowhere near that! Wet test gives me 100-110. 65 dry seems awefully low considering it starts well. My compression gauge is a good quality snap on that has never led me astray. Doesn't use oil, but call me crazy, I see a tiny bit of man glitter on the oil dipstick?? May need to cut open the oil filter and unfold the media as I do on my car race engines.
Just think this is wierd, I thought the yamys were bulletproof plus this only has 8000kms on it. However, we don't know the hist as my friend bought it used at the begining of the winter. I also measured the resistance of the coils while I had it apart, primary should be 1.2-1.6ohms? I had 3.2 ohms. I would throw coils and plugs at it, but that's not going to help compression...
This is a dirt bag to work on, everything miserably buried.
I miss my old sxr 700 red head!
Interested in your thoughts.
Thank you
edit: can't give a % leakdown as my tester is at work, but did put air in cyliders at tdc and didn't hear any obvious
Last edited:
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welcome!
07 where 1st model year and had counter balancer gear/shaft issues. quite a few members have experianced/fixed this. if memory serves @cannondale27 and @grizztracks have gotten into this repair. @Mooseman might have played with this too. i do know there was a thread with pics of a failure recently.
07 where 1st model year and had counter balancer gear/shaft issues. quite a few members have experianced/fixed this. if memory serves @cannondale27 and @grizztracks have gotten into this repair. @Mooseman might have played with this too. i do know there was a thread with pics of a failure recently.
74Nitro
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If you have the bad gears it can contribute to metal filings obviously.
However, I don't think it is in anyway related to low compression. The machine I fixed has been running fine to the best of my knowledge.
Mooseman
I'm not all knowing. Post your question in forum.
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No problems with the decomp system unless the timing chain gears have actually failed.
The decomp just changes the timing of the exhaust cam to lower the compression a little. Never heard of that system ever failing. Only time it was ever mentioned was for the long crank and cold starting issue where the decomp springs would be replaced along with the ECU.
To find exactly what the issue it with your motor, you'll need to do a leakdown test. This should tell you if it's a ring, head or valve issue.
I once had a motor from a scrapped Phazer that had low compression and leaked compression everywhere. It had been severely overheated to the point that sensors melted.
What's the mileage on yours? If it's a low mileage unit, it could be another one with a failing reduction gear. If you do find metal and it hasn't completely failed, now is a good time to replace it like in that other thread.
The decomp just changes the timing of the exhaust cam to lower the compression a little. Never heard of that system ever failing. Only time it was ever mentioned was for the long crank and cold starting issue where the decomp springs would be replaced along with the ECU.
To find exactly what the issue it with your motor, you'll need to do a leakdown test. This should tell you if it's a ring, head or valve issue.
I once had a motor from a scrapped Phazer that had low compression and leaked compression everywhere. It had been severely overheated to the point that sensors melted.
What's the mileage on yours? If it's a low mileage unit, it could be another one with a failing reduction gear. If you do find metal and it hasn't completely failed, now is a good time to replace it like in that other thread.
torkyolds
Newbie
With 50-60 psi dry compression test (on the particular engine) , safe to say the engine needs to come apart, no?
- Joined
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2011 apex xtx
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1988 vk 540
yes engine will need to come apart or at very least head off to inspect valves.
torkyolds
Newbie
Well, I was hoping with both cylinders being low on compression that I was into a valve timing issue. The timing marks seem to line up dead nuts and the Decompression
mechanism on the exhaust cam looks like it moves freely.
