R90\6 1974 pushrod

Discuss all things 1970 & later Airheads right here.
KC1953
Posts: 8
Joined: Mon Oct 31, 2022 10:55 am

R90\6 1974 pushrod

Post by KC1953 »

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.
Rob Frankham
Posts: 1213
Joined: Thu Aug 26, 2010 2:11 pm
Location: Scotland UK, 20 miles from civilisation up a dead end road!
Contact:

Re: R90\6 1974 pushrod

Post by Rob Frankham »

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

Rob
ImageImageImage
User avatar
gspd
Posts: 1041
Joined: Tue Aug 03, 2010 8:04 pm

Re: R90\6 1974 pushrod

Post by gspd »

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

Why did you take the engine apart?
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
KC1953
Posts: 8
Joined: Mon Oct 31, 2022 10:55 am

Re: R90\6 1974 pushrod

Post by KC1953 »

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.
User avatar
melville
Posts: 1814
Joined: Tue Aug 03, 2010 8:32 am

Re: R90\6 1974 pushrod

Post by melville »

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.
Call me Mel. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me at home, I thought I would ride about a little and see the other parts of the world.
User avatar
gspd
Posts: 1041
Joined: Tue Aug 03, 2010 8:04 pm

Re: R90\6 1974 pushrod

Post by gspd »

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?
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
Kurt in S.A.
Posts: 1647
Joined: Tue Aug 03, 2010 12:08 pm

Re: R90\6 1974 pushrod

Post by Kurt in S.A. »

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
KC1953
Posts: 8
Joined: Mon Oct 31, 2022 10:55 am

Re: R90\6 1974 pushrod

Post by KC1953 »

IMG_20221101_123504132.jpg
IMG_20221101_123504132.jpg (1.51 MiB) Viewed 884 times
This is the pushrod. Each end has a hole.
KC1953
Posts: 8
Joined: Mon Oct 31, 2022 10:55 am

Re: R90\6 1974 pushrod

Post by KC1953 »

Well that clears that up,
Thank You!
KC
jackonz
Posts: 206
Joined: Sat Oct 30, 2021 5:29 pm

Re: R90\6 1974 pushrod

Post by jackonz »

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
Phil J

Nelson NZ.
Post Reply