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I took a chance on a 74 R90\6. I pulled the head, jugs and pistons out. We think I might have a clogged pushrod. I haven't been able to find any way to clean these on line. maybe someone has a suggestion.

My apologies, I'm probably being thick but I can't think what you mean by a 'clogged pushrod'. Can you explain...

Rob

?????
One clogged pushrod???
????
Post a picture of it.

Why did you take the engine apart?

I had to open up the engine as the right cylinder was stuck. I had the cylinder soaking, laying on a tire, for 2 months. All the ATF/Acetone in the world made no difference. Heated the cylinder, wouldn't budge. I got it out. The piston was shot as was the cylinder. When we took off the head on the right cylinder one side was really bad, black. The cylinder was beyond repair, I have since located another set up.
The assumption was the pushrod had some issue, it was fairly black, I assumed the holes on the ends had fluid going through them. Maybe it's nothing. The weird thing was, both of these pistons were spotless, not a scratch. All the fluids were clean except the fluid in the forks.
Another thing, the front turn signals mount to the headlight brackett, the turn signal plate is gone.

Airhead pushrods should be dry inside. No oil flows through them.

Oil for the rocker gear flows down the upper cylinder studs and to the rocker shafts, then drains back to the sump via the pushrod tubes.

KC1953 wrote: ↑Tue Nov 01, 2022 10:33 am The assumption was the pushrod had some issue, it was fairly black, I assumed the holes on the ends had fluid going through them.

Airhead pushrods should have a ball on each end, not a hole.
Can you post a pic of what you are referring to?
Con rod maybe?

Are you sure it's a hole? Have you tried putting something into that dimple? As stated, the rods are hollow but there's no oil moving through the tube. The oil goes through the pushrod tube...not the pushrod itself.

Kurt

This is the pushrod. Each end has a hole.

Well that clears that up,
Thank You!
KC

That looks like an aftermarket pushrod check this out, I dot recall mine having holes when I had mine stripped out.

https://cognitomoto.com/products/valve- ... 8089853043