free website stats program new noise... | Page 2 | Harley Davidson Forums

new noise...

Still haven't pulled the primary cover yet, but will start tomorrow. One more question, as I was checking things over this weekend looking for the culprit (Jack, I tightened the exhaust to 10 ft lbs) I pulled the plugs just to check them. They've been in for a few years now. The front plug was pretty crusted up. Black sooty (EDIT) on it. The rear plug was nice and brown. I cleaned this plug and put it back in. Could the plug be creating this noise somehow?

HMMMM, any thing is possible, carbon build up usually will cause a mis fire, but if a spark is jumping from a plug wire HMMMMM spray some water on the wires to see if it mis fires
 
Last edited by a moderator:
Still haven't pulled the primary cover yet, but will start tomorrow. One more question, as I was checking things over this weekend looking for the culprit (Jack, I tightened the exhaust to 10 ft lbs) I pulled the plugs just to check them. They've been in for a few years now. The front plug was pretty crusted up. Black sooty (EDIT) on it. The rear plug was nice and brown. I cleaned this plug and put it back in. Could the plug be creating this noise somehow?

AFTER you check the compensator to make sure the comp nut is tight, you may want to try this:

Harley Davidson Forums

TQ
 
Last edited by a moderator:
TQ, ive checked the comp nut..it is tight. i gotta say i was impressed with how clean the primary was once i opened it. the drain has always, everytime I've changed the oil, had fuzz on it. I expected to find some in the case but didn't. the chain itesel had about a 1/2 of play..i don't think it was too loose/tight. The tensioner looked to be new. I did notice the fins on the front cylinder around the exhaust had black soot on them. I'm thinking i had aleak...could I have burnt that valve?
 
TQ, ive checked the comp nut..it is tight. i gotta say i was impressed with how clean the primary was once i opened it. the drain has always, everytime I've changed the oil, had fuzz on it. I expected to find some in the case but didn't. the chain itesel had about a 1/2 of play..i don't think it was too loose/tight. The tensioner looked to be new. I did notice the fins on the front cylinder around the exhaust had black soot on them. I'm thinking i had aleak...could I have burnt that valve?
Run a compression test and compare both cylinders
 
Run a compression test and compare both cylinders

Ok, Jack i ran a compression check with the engine cold. The front cylinder, which had the sooty plug ranged between 180-210. The rear cylinder was between 180-190. I held the throttle wide open during test. The book calls for running the test on a hot engine and says anything above 125 is good. I figur a cold engine would account for the higher readings. Ill run it again when i can ride and get the engine hot.
 
Ok, Jack i ran a compression check with the engine cold. The front cylinder, which had the sooty plug ranged between 180-210. The rear cylinder was between 180-190. I held the throttle wide open during test. The book calls for running the test on a hot engine and says anything above 125 is good. I figur a cold engine would account for the higher readings. Ill run it again when i can ride and get the engine hot.

That looks good to me:D
 
The book calls for running the test on a hot engine and says anything above 125 is good.

When I saw that spec, I couldn't believe that it could be that low so I looked it up and to my surprise, that's what it is. A FINAL reading of 125 PSI is considered normal on a factory stock late model twin cam.

I can't believe the MoCo would really believe that's normal. It might be acceptable but I can't believe it's normal.

Just a comment, nothing more.:)
 
When I saw that spec, I couldn't believe that it could be that low so I looked it up and to my surprise, that's what it is. A FINAL reading of 125 PSI is considered normal on a factory stock late model twin cam.

I can't believe the MoCo would really believe that's normal. It might be acceptable but I can't believe it's normal.

Just a comment, nothing more.:)

Hoop, this being the first time I've ran a compression check on anything, I was expecting a reading somewhere near what the books said (125). I was shocked when it was so much higher.
 
The readings you got are more realistic. I really would not want to see 125 PSI like the manual says.

Also remember that compression gauges have peak detect check valves in them, so the pressure will rise to a peak value after several strokes. In a perfect world, the first stroke reading would be equal to the final peak reading but that never happens. Usually after 4 strokes, the peak reading will be reached. The more tightly bunched they are, the better.

Test on engine #1 100-120-140-150

Test on engine #2 135-140-145-150

Each engine had 4 test strokes & both tests have a final reading of 150 psi but I would rather have the results of test #2.
So I am thinking when you say your reading was 180-190,, I am thinking the 1st stroke was 180 with a final reading of 190 which would be Great.
 
The readings you got are more realistic. I really would not want to see 125 PSI like the manual says.

Also remember that compression gauges have peak detect check valves in them, so the pressure will rise to a peak value after several strokes. In a perfect world, the first stroke reading would be equal to the final peak reading but that never happens. Usually after 4 strokes, the peak reading will be reached. The more tightly bunched they are, the better.

Test on engine #1 100-120-140-150

Test on engine #2 135-140-145-150

Each engine had 4 test strokes & both tests have a final reading of 150 psi but I would rather have the results of test #2.
So I am thinking when you say your reading was 180-190,, I am thinking the 1st stroke was 180 with a final reading of 190 which would be Great.

Thanks, Hoop. Good info. Now if I could just figure out where this noise is coming from.
 
Back
Top