Engine Compression Problem-

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Sep 14, 2008 | 08:56 AM

#11

russl179

Thread Starter

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Joined: Apr 2006

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From: Matthews, NC

Quote:

Originally Posted by vettedog72

Agreed, not likely to be rings and pistons UNLESS it has some racing pistons with high compression. It ought to be a very strong runner; if the only problem is hard starting when hot, get the auto compression release (for each cylinder head).

Everything is stock.

Sep 14, 2008 | 09:53 AM

#12

Ram

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Joined: Sep 2005

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From: USA

As stated get some competent wrench on your side. IMHO that compression is "Great". One it matches and two its a high number.

It showes that the pistons, rings and cylinders have a POSITIVE seal. Also as mentioned a leak down is the proof in the pudding.

So as for getting H-D to change your pistions and rings for a SLOPPY set that does not get that set of numbers your asking for trouble.

I question as also mentioned the oil PSI.

Additionally how long has that oil been in the engine? Is it fresh? Or have you over 3K miles on it?

And one other thing that I've forgot to mention, what is the condition of your battery? Have you had it load tested?

Last edited by Ram; Sep 14, 2008 at 09:56 AM.

Sep 14, 2008 | 09:59 AM

#13

mtclassic

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I have seen high compression with bad rings, only a leak down will really tell you. What was the reason you were having the compression checked in the first place? Hard starting, excessive pinging that might help knowing what prompted you to take the bike in.

Sep 14, 2008 | 10:43 AM

#14

alame

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From: Mission BC

I would get that compression done again, by someone else preferably/another gauge, something isn't quite right there me thinks, and to have that answer for the high readings ?

Sep 14, 2008 | 11:56 AM

#15

harpinc

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Joined: Jun 2008

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Both cylinders exactly 60psi too high???? Hmmmmmm.. I think I would have someone else check it out..

Sep 14, 2008 | 12:32 PM

#16

mtclassic

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I should have stipulated in my post the bad rings did not make the compression high but the compression shown good even tho a ring was broken in several pieces. So just because the rings are bad does not mean the compression will be low or not equal.