Board index Flathead Power-Technical Questions, Answers, and Suggestions Twin Cams Oil Spill

Oil Spill

Post Sat Jul 03, 2010 10:28 am

Posts: 9
Location: Bellingham, Washington, USA
Bought a Gilroy Scout (yes, Marge, I know it's not a real Indian) a month ago. Engine is a Twin Cam 88 Super Stock. Haven't had time to ride it except on trips to town (40mph or less). I noticed a bit of oil splattering on the aft exhaust header, but nothing a little wipey-wipey at end of run didn't cure.

At the beginning of the week I finally got her out for 4 hours and made it to 5th gear a few times. She was spewing more than usual, and once home there was more lube oil on the bike than in it, it seemed. Even an old Vincent would have to take a back seat to this leakage.

What have I done? I adjusted the pushrods...the o-rings on the covers seem to be worn because they wouldn't hold the covers in place when I installed the keepers. Had to use my third hand ;)

This bike is a 2001 model with less than 6500 miles, so she's been sitting around a lot. Dried up/deteriorated gaskets and seals are my first suspects, especially the pushrod cover o-rings. Rocker box gaskets look new, judging from the edges.

The bike parts manual lists 2 separate rocker box gasket for chrome box covers, one for billet box covers (these are chrome). S&S just lists one kit. No o-ring kits for pr covers are listed on the S&S site.

Any feedback would be appreciated. This is my first American machine, and I'm still learning.

Post Wed Jul 07, 2010 11:36 am

Posts: 152
Location: Carver, MN

I am pretty sure that your motor is an 88 inch S&S Super Stock (Evo Style) - not a Twin Cam. The o rings should be interchangeable with stock Harley Evo pushrod tube o rings, which you should be able to get at most any bike shop. Be sure that an upper o ring didn't get out of place when re-assembling.
The clips should have enough tension on them that they need a little prying with a screwdriver to install. If not, the springs in the pushrod tubes may have lost their tension also.

Post Thu Jul 08, 2010 3:05 pm

Posts: 9
Location: Bellingham, Washington, USA
Thanks, Lee for educating me. Knowledge is power.

I was really careful to get the o-rings seated properly, and even popped off the clips and re-seated them at the first sign of oil. The springs are strong.

After reading your post, I contacted S&S and the following was exchanged:


The engine has raised lettering in the left side crankcase casting that says: 80L Super Stock. The engine number (stamped on the right side) is: *A04971* .

Can you tell me what this engine is? I've also attached a couple of photos.

Response from S&S:

Yes those are stock style H-D EVO rocker boxes you can get gaskets from Harley H-D 17038-90 or S&S 90-4046 and yes it appears to be an 88” evo style motor.


This makes a difference. I tried to ID this mill online, but couldn't seem to get any info that applied. Now I know.

Thanks again!
rocker_box_both_01W.jpg (226.52 KiB) Viewed 5708 times

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