Bent pushrod or something else?

slomo

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Or like me that fooling around is big pain just to get to the point. It is a waste my time to watch stupid stuff beside I got too things that got to be done each day. Anyway I don't his videos any more.
I thought you had Taryl teeth and the wig Startech? One of you guys turned me on to him. Taryl is off the chain. Don't care what you impatient babies think LOL. :) (y)

Guess you guys need to watch boring donnyboy. Right off the bat, need a 5/16" wrench and a #2 Philips screwdriver. Look she runs great. The end.... LOL

In all honesty, I used to FF to the repair part. Now I watch the comedy part too. Better than Netflicks.

P.S. you guys know you can fast forward youtube videos right? Hold the cursor just right, you see the video in frames? Surely Shirley??

slomo
 

hotroddr32

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I got the head off this evening and the exhaust valve will barely opens. Intake looks a little more normal, but that pushrod was bent too. Why would that one be damaged? Also, I don't see anything wrong on the other head, Seems like the guides there barely sit higher than the second coil on the springs. Would it be safer to go ahead with replacing both? I wonder what the chances are one being damaged and the other not.
 

slomo

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1.Remove all the dirt, grass and oil mess from the cooling fins, ALL the way around each cylinder. Overheating will cause this.
2.Post up a lot of pictures of the bad head and valves. Good light and a steady camera. If you have a cell for a camera, TURN IT HORIZONTALLY and rest off a bench while snapping the shot.
3.What was step #1 again?
4.Pictures of the good head and bad head for comparison.
5.Repeat step #1. Even the thinnest dirt film will insulate the aluminum slowing heat transfer. These are air cooled engines that get to full op temp in roughly 60 seconds. Use a good degreaser like Dawn and a nylon brush.

slomo
 

hotroddr32

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Pic below is the bad head followed by the other suspected good one. I don't see much wrong with it, but the guide on first one has definitely backed out.


1623634803551.png

1623634734825.png



Bad head
 

slomo

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Confirmed, valve guide has left the building LOL. I would pull all the valves out to make sure the good one is okay, hasn't started to move either.

Most of the time this is from overheating. You have to keep those cooling fins totally clean and clear.

If this was mine. I would take it to an automotive machine shop. Shouldn't cost too much. See if they can push the guide back or get their opinion on replacing the head. They are the pros on this stuff.
I got the head off this evening and the exhaust valve will barely opens. Intake looks a little more normal, but that pushrod was bent too. Why would that one be damaged? Also, I don't see anything wrong on the other head, Seems like the guides there barely sit higher than the second coil on the springs. Would it be safer to go ahead with replacing both? I wonder what the chances are one being damaged and the other not.

"barely sit higher" LOL That little guy is about to jump out of the head.
 

hotroddr32

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Confirmed, valve guide has left the building LOL. I would pull all the valves out to make sure the good one is okay, hasn't started to move either.

Most of the time this is from overheating. You have to keep those cooling fins totally clean and clear.

If this was mine. I would take it to an automotive machine shop. Shouldn't cost too much. See if they can push the guide back or get their opinion on replacing the head. They are the pros on this stuff.


"barely sit higher" LOL That little guy is about to jump out of the head.
"Barely sits higher" referred to the guides on the head still installed on the motor.
 

Pmoon1

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I had the same problem with a BS 20 horse engine, valve guide worked its way out resulting in a bent push rod. I pushed the guide back in and using a punch peened the edges around the guide, straightened the push rod and put it back together. The engine ran fine and never had the same problem.
 

bertsmobile1

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Moving guides are a symptom & not the problem, excepting the 0.01% manufacturing faults.
The guide moves because the head gets too hot.
Head gets too hot because
1) cooling fins are obstructed
2) engine is run at less than full speed
3) timing is too far advanced
4) carb is way too lean.
 
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