Those of you that have known me during the last 3-4 years, are probably thinking, "Here we go again", but...

...here we go again.  You've seen photos like these before

This is about like my last project in NC, before we moved.

Should I start a new topic?  I don't know.  I just know that I gotta go back through the motor and do some more mods to the frame before spring comes

Here is my frame again.  It's on my "standard" bike stand 8)



Here's my engine.  It sits on a "Poor Man's Engine Stand"

Hell, Billy wrote on 12/31/69 at 16:00:11:


Yep.  I am a little surprised by all this, but I can't find any other logical reason for all the oil in the combustion chamber.  Even the chance that the valve guide seals are leaking doesn't fit this situation.  That only causes small puffs of smoke on startup

I think it is actually a combination of things.  The cylinder was glazed and there was a small gouge in the wall (not sure how it got there).  The honing I did to correct that problem mixed with the used rings is the best I can figure...add 130 miles of riding and the rings went bad.

At any rate, this topic ought to go to the Cafe now...this wrench is gonna do more than just fix the engine now that winter is moving in...and this bike has always been a "work in process" and I want to get her ready for the next FSSNOC ride

PS - if I ever get this bike the way I'd like it, then a restoration project, like your Indian, sounds like fun.  Maybe someday

Savage_Greg wrote on 12/31/69 at 16:00:11:


Be careful to not "over lube".  With WD40 / CRC the rings seat in 50 - 100 miles.   The Moly, even though a great lube, may extend that time......too slippery....

Man your rebuild is killing me, I'm a long way wear wize from needing to do a overhaul on my '02 but the motorhead in me is screaming to do a tear down and a performance rebuild. Gotta calm down and have another brew. Going one size over on the piston is standard cause the machine shops charge per oversize cuts. Going two over sizes cost twice as much as cutting the bore for one oversize. You would also loose some mass in the cylinder wall and could run a little hotter with a 2x overbore. That being said, life is short, if it is apart again go for the max for what you can afford and then some.

Back to Dr_Jim...more brainstorming

Didn't you ask me if the valve guide seals could be leaking?

I got around to looking at the head again, and noticed a lot carbon build up on the outlet side of the exhaust valve seats.  In fact, there is carbon build-up on the valve seat itself.

Can leaking valve seals do that in 130 miles?

T Mack 1 - FSO wrote on 01/04/08 at 10:31:50:

First off, we can eliminate gas as the source of the carbon.  The carb, petc0ck, tank, and all that is just fine.  As well, I'm actually running leaner than most with a 152.5 main.

Yes, carbon on the seat face.  On the ground sealing surface.

Yes, I thought the seat would be cleaned by the valve operation (though it should be burning clean anyway).

The area "beyond" the valve seat has a generous build-up of carbon in the port...the port that was spotless 130 miles earlier.

I, too, figure that oil leaking through the valve seal would be blown out the exhaust and never enter the cylinder.  In fact, I always thought that leaking valve seals only leaked "a little bit" from gravity after the engine was off anyway...and smoked a bit on startup.

SOooo, it would seem that the oil must entering the flow before the exhaust valves rather than after them.  Right?

Still sound like rings/piston/cylinder?

Max_Morley wrote on 01/04/08 at 13:08:52:


Good thought.  Well, ah, er, I can't say that I went to extremes to wipe off the honing residue.  I did take it into the kitchen though (when the spouse was away)

End gap on one of the rings is over and one is under spec.  The oil ring looks worn but no way to measure it anyway.