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oil leak around head gasket.

mschehen
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Posts: 47
Joined: Tue Jun 01, 2010 11:12 pm
Location: Albany, Or

oil leak around head gasket.

Post by mschehen » Sun Dec 22, 2013 5:04 pm

So I am having a problem with an oil leak around the head gasket on my dream. This is a project bike and I bought the motor as a supposed rebuilt. Just put it in the first time and it had major blow by and pushed oil out of the breather hose. Tore it down and found a compression ring in upside down. Figured that was it and reassembled it to have it leak worse. (I should mention the builder used tons of gasket sealer so it obviously had a leaking issue before as well) I pulled it down again and found the o rings were not any thicker then the head gasket so I bought new thicker ones and put it together again. Just started it and it runs great (always has) but still seeping oil around the head gasket. I even used permatex this time. The head did not appear to have any warping or cracks. Anyone have any ideas?

conbs
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Posts: 989
Joined: Mon Mar 16, 2009 3:29 pm
Location: SW Idaho

Oil leak

Post by conbs » Mon Dec 23, 2013 11:09 am

Do a search on this site.

The blow by could be the plate/gasket under the top cover is in wrong.

The iron skull in the head for the compression chamber can also separate from the aluminum.

The third thing is re-checking the torque values on the nuts atop the cover. When it heats up and cools down the first few times it can loosen up everything.

I assume you do have the knock pins in between the head and jugs.

Finally, I am pretty sure the oil passageways changed during production. If I understand correctly, not all heads will work with all jugs. LM, do I have that right?

Some ideas. Hope they help.

mschehen
honda305.com Member
Posts: 47
Joined: Tue Jun 01, 2010 11:12 pm
Location: Albany, Or

Post by mschehen » Mon Dec 23, 2013 11:34 am

Thanks for the ideas. The blowby went away when I flipped over the ring. I retorked after the first run and didn'tget more then a 1/4 turn before my wwrench clicked. (I went to 20lbs is that enough?) The guy I bought the motor from thinks the head may have been milled at some point, which would answer the question of why it runs so much stronger then my stock bikes. I am going to pull it back down and make sure the dowels are not too long and are letting the head come all the way down. Will keep you posted.

LOUD MOUSE
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Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Re: Oil leak

Post by LOUD MOUSE » Mon Dec 23, 2013 11:38 am

Are you using the BLUE soft gaskets at the top covers?
The heads all interchange.
The cylinders were changed from the 8 hole to the 9 hole in (mid?) 1962 but will have no effect with the area where the head and cylinder contact. .................lm
conbs wrote:Do a search on this site.

The blow by could be the plate/gasket under the top cover is in wrong.

The iron skull in the head for the compression chamber can also separate from the aluminum.

The third thing is re-checking the torque values on the nuts atop the cover. When it heats up and cools down the first few times it can loosen up everything.

I assume you do have the knock pins in between the head and jugs.

Finally, I am pretty sure the oil passageways changed during production. If I understand correctly, not all heads will work with all jugs. LM, do I have that right?

Some ideas. Hope they help.

conbs
honda305.com Member
Posts: 989
Joined: Mon Mar 16, 2009 3:29 pm
Location: SW Idaho

Oil leak

Post by conbs » Mon Dec 23, 2013 4:16 pm

LM, thanks for straightening me out on the heads being interchangeable.

If he has a oil leak at the head gasket will the gaskets under the top cover affect that?

Thank you for sharing your knowledge with all of us.

OldStan
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Posts: 548
Joined: Wed Jul 14, 2010 5:33 pm
Location: Galt, California

Post by OldStan » Mon Dec 23, 2013 4:42 pm

If the head has been milled, you might check that the studs aren't bottoming out in the acorn nuts.

Another place to check is the side covers in the head (over the cam bearings.) If they're not seated properly it can leak into the cavity around the spark plugs or onto the fins.
63 CA78

LOUD MOUSE
honda305.com Member
Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Re: Oil leak

Post by LOUD MOUSE » Mon Dec 23, 2013 7:54 pm

I installed the BLUE top gaskets on 2 engines and had weeping at the top and head/cylinder area.
I checked the torque of the cap nuts and found the nuts were not near to the 21# I had torqued them to.
I had to remove both engines and replace the BLUE gaskets.
That cured the problem. .................lm
conbs wrote:LM, thanks for straightening me out on the heads being interchangeable.

If he has a oil leak at the head gasket will the gaskets under the top cover affect that?

Thank you for sharing your knowledge with all of us.

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