My Harley is leaking oil...

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My Harley is leaking oil...

Postby Rench » Mon May 27, 2019 8:10 am

But seriously... She is. First time oil leak in 15.5 yrs looks to be coming pretty clearly from the rear head gasket, and also lacking some punch on acceleration. On a quick search, lots of folks say they've never seen a blown head gasket on a sportster, to just check valve covers.

The loss of power kinda seals the deal for me but I thought I'd che k with the hive mind. Thoughts?

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Re: My Harley is leaking oil...

Postby DerGolgo » Mon May 27, 2019 8:21 am

Loss of oil and loss of power?
How would valve covers affect power?

I may be an utter ignoramus when it comes to swinging a wrench, but just from applying the logics to what little I know of four-stroke otto-cycle engine design, head gasket does sound like a likely culprit.
Is checking compression in the cards?
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Re: My Harley is leaking oil...

Postby red » Mon May 27, 2019 9:53 am

Sounds like how my Ulysses behaved around the time I found my front head gasket leak.
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Re: My Harley is leaking oil...

Postby Sisyphus » Mon May 27, 2019 3:22 pm

You're losing more compression than oil.
My money says head gasket. I had a head gasket fail on a diesel engine and power was somewhat diminished but it was pressurizing the coolant system. Because your bike isn't liquid cooled you wouldn't have this indication.
I bet if you pulled the head off you'd see witness marks in the form of carbon leading to where you found oil weeping out.
If you're lucky it'd just be a matter of cleaning everything off and seating a new head gasket with the proper torque and re-torquing after a heat cycle or two, depending on the manufacturer's protocol.
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Re: My Harley is leaking oil...

Postby 0l4fderstout » Tue May 28, 2019 7:04 am

what does a compression test say? (if it is the head gasket, I'd get the head milled before reseating it, so the gasket isn't as likely to blow out in the future)
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