7.....107'' mosquito killers

[88b]

Fuelling say they will have stem seals out soon so I'd think that was the problem. Back to 05 again then.

[rbabos]

That Photo looks like a typical Harley Piston top....

With raw oil running down from the intakes? Should be dry.
Ron

[rigidthumper]

Possible that's just the intake breathing in the crankcase breather mist? Looks like both intakes have "some" residue, and the majority of the blow by on the near side?

[rbabos]

Possible that's just the intake breathing in the crankcase breather mist? Looks like both intakes have "some" residue, and the majority of the blow by on the near side?

Looks to me leakage after shut down. Any breather mist would be burnt so the piston top should remain dryer looking. To get that much mist, to the point of liquid laying there the engine would be well worn out for that. Valve seal fit is the most likey cause, between all the other possibles. Don't know why it takes so long for something so simple to be determined. Probably is, but they aren't talking about it.
Ron
Ron

[mobe]

I have not personally laid eyes on the heads on one of these but from what I understand from talking to my tech there is a plug in the combustion chamber that is used to machine the oil passages. The theory is that it may be weeping oil around the plug at shutdown and pooling on top of the piston. 
 

[rbabos]

I have not personally laid eyes on the heads on one of these but from what I understand from talking to my tech there is a plug in the combustion chamber that is used to machine the oil passages. The theory is that it may be weeping oil around the plug at shutdown and pooling on top of the piston. 

Not picking on you but the techs explanation sounds fishy to me. If it can leak oil in a static state sitting there, imagine what the hot compression gasses do going into the oil galley past that plug with the engine running.
Ron

[Ohio HD]

I have not personally laid eyes on the heads on one of these but from what I understand from talking to my tech there is a plug in the combustion chamber that is used to machine the oil passages. The theory is that it may be weeping oil around the plug at shutdown and pooling on top of the piston. 

Not picking on you but the techs explanation sounds fishy to me. If it can leak oil in a static state sitting there, imagine what the hot compression gasses do going into the oil galley past that plug with the engine running.
Ron

Sure would seem unlikely to have an oil galley plug there.

[packrat56]

I have not personally laid eyes on the heads on one of these but from what I understand from talking to my tech there is a plug in the combustion chamber that is used to machine the oil passages. The theory is that it may be weeping oil around the plug at shutdown and pooling on top of the piston. 

Not picking on you but the techs explanation sounds fishy to me. If it can leak oil in a static state sitting there, imagine what the hot compression gasses do going into the oil galley past that plug with the engine running.
Ron

Sure would seem unlikely to have an oil galley plug there.

  It seems quicker just to weld ,if the passage  ends in the chamber.

[1FSTRK]

I have seen no sign of plugs or passages in any pictures so far. Given the oil travels through the exhaust side of the heads it seems unlikely oil passages have anything to do with this.
http://harleytechtalk.com/htt/index.php/topic,93224.msg1077687.html#msg1077687

Added
Now this pic shows some promise of a link to the theory
http://harleytechtalk.com/htt/index.php/topic,93224.msg1077804.html#msg1077804
If this plug was to leak it could add oil and some pressure to the rocker cover area and possibly cause brather problems and valve seal problems.

[rbabos]

I have seen no sign of plugs or passages in any pictures so far. Given the oil travels through the exhaust side of the heads it seems unlikely oil passages have anything to do with this.
http://harleytechtalk.com/htt/index.php/topic,93224.msg1077687.html#msg1077687

Added
Now this pic shows some promise of a link to the theory
http://harleytechtalk.com/htt/index.php/topic,93224.msg1077804.html#msg1077804
If this plug was to leak it could add oil and some pressure to the rocker cover area and possibly cause brather problems and valve seal problems.

Agree, only exhaust passages and no real connection. Doubt there is any meaningfull oil pressure in that circuit since it basically goes in and dumps in the sump after. In the Fuellings pic,  oil is running downhill from the intake valve. Anyone who has dealt with poor valve seals before, this is a perfect indicator of what happens on shut downs. Restarts it will smoke then clear out. Wonder if the exhaust port is wet also?
Ron

[-deuced-]

If that's oil that has entered the combustion chamber after shutdown on that piston in the Feuling pic, why isn't it towards the top of the pic? Do M8's have the side stand on the right hand side?
Wonder what the rear piston looks like. I'd also like to see pics of the heads, valves, ports etc.

I also noticed on Feuling fb page that the wee rods have four valve heads and adjustable rocker arms. I didn't know that. Surprised there was no mention of that on this site when the M8 was released.

[joe_lyons]

If that's oil that has entered the combustion chamber after shutdown on that piston in the Feuling pic, why isn't it towards the top of the pic? Do M8's have the side stand on the right hand side?
Wonder what the rear piston looks like. I'd also like to see pics of the heads, valves, ports etc.

I also noticed on Feuling fb page that the wee rods have four valve heads and adjustable rocker arms. I didn't know that. Surprised there was no mention of that on this site when the M8 was released.

No rocker arms on vrod.

[rbabos]

Wee rod might be referring to the Street engine or at least better be since the Revolution has no rockers. In case anyone cares the Rev X engine in the Street has a single oh cam per head and rockers with adjusters because they need them. Not to be confused with the hydraulics of the M8 that really doesn't.
Ron

[joe_lyons]

My bad

[rbabos]

My bad

Only assuming that was the terminology. As for where the oil comes from, first step is if the twin cooled does the same, then it has nothing to do with oil cooled heads so it's back to the seals.
Ron

[-deuced-]

Sorry, yes I was referring to the Street.

Another thing I saw on that fb page, Twin Cams are now old school. lol

[rbabos]

Sorry, yes I was referring to the Street.

Yup, I heard the term before so figured that's what you were talking about.
Ron

[-deuced-]

Anyway, in that M8 piston pic, it looks like oil has flowed into the right hand side exhaust valve pocket. Why? Why hasn't it flowed towards the the left hand side of the piston? Wouldn't that be the lowest point when the bike is parked?

[Bike31]

A couple of guesses having not seen an M8 head:

Intake flow hits the right valve first or most...same for any oil mist.

Internal bridging captures oil around the right valve seal more than the left when parked. Previous pic...rear cylinder head...intake valves at top.

[rbabos]

Anyway, in that M8 piston pic, it looks like oil has flowed into the right hand side exhaust valve pocket. Why? Why hasn't it flowed towards the the left hand side of the piston? Wouldn't that be the lowest point when the bike is parked?

Bike might have been on a lift and upright or close to it. Since both valves open the same time it looks like the right intake was the one leaking.
I do agree, on the side stand it would run to the left.
Ron

[Eccool]

So three months to the day after this thread was started, is there still no definitive answer for what causes this?  Is the problem (smoking M8's) still out there?