350 Rancher Engine problems

DG Rider

DG Rider

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I researched what 30psi could mean on the worldwide web. Just to see repair estimates...
Anyways, I learned about decompression valves. To help turn engines over. Some say 68psi is where you’ll see them kick in on Honda (ex300/400) forum I was reading.

But no-one seemed to think 30 was a good reading. Lulz
Lol..yeah...30 does nothing.
The automatic decompression release is (typically) a spring loaded ramp built into the cam that extends below a certain RPM and bumps the exhaust valve open for a bit of the compression stroke. It is functional at cranking speed, obviously. That's why the compression spec is lower than you would see normally.
 
JsheII3

JsheII3

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Lol..yeah...30 does nothing.
The automatic decompression release is (typically) a spring loaded ramp built into the cam that extends below a certain RPM and bumps the exhaust valve open for a bit of the compression stroke. It is functional at cranking speed, obviously. That's why the compression spec is lower than you would see normally.
DG, much appreciated. Just wanted to say that for the record. (Before PistonHonda gets this whole thread removed.)
Ha!
 
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snuffnwhisky

snuffnwhisky

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Does your compression gauge have a typical air chuck connection?
 
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Here's a sample video. I had to repair the threads on my oil tank and I wanted to be sure I got the metal shavings out after it was done.

 
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JsheII3

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You can turn the motor over where the piston is at the top of the cylinder, screw that hose in and hook an air compressor to it. Feel for a bunch of air coming back through the carb, exhaust or crankcase.
What would this indicate?
And also, how hard would it be to stop the piston at the top of the stroke just using the electric start?
 
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snuffnwhisky

snuffnwhisky

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What would this indicate?
Air coming back through the carb = intake valve. Exhaust = exhaust valve. Oil fill cap = Piston and/or rings.

I've saw valves stick open from lack of oil and heat. The little valve springs are pretty soft and it doesn't take much for them to stick in the guide.
 
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