KX033-4 intake pulse

[GBJeffOH]

I get positive pressure pulses on the intake.

I think I should check the compression, leakdown and valve clearance.

Video link
KX033

 

[North Idaho Wolfman]

Before you jump into a tear down, remove this pipe and see what you get.
Then check valves next.
Compression test will be good to have, just so you know what cylinder has the issue.

 

[GBJeffOH]

Before you jump into a tear down, remove this pipe and see what you get.
Then check valves next.
Compression test will be good to have, just so you know what cylinder has the issue.

View attachment 177237

Good idea.

I plugged that. Then I set the oil full cap on just enough to seal. It stayed put.
Also if I hold my finger on 020 there is no pressure.

I had to order the compression tester.

 

[GBJeffOH]

The compression is 475 460 and 470.

The valve clearance good. .006 is real loose. It is less than. .010.

 

[#40Fan]

With the valve cover off, bar/turn the engine over and make sure all of the valves (especially exhaust) are opening the same amount.

 

[North Idaho Wolfman]

The compression is 475 460 and 470.

The valve clearance good. .006 is real loose. It is less than. .010.

.006 is too tight, .007 to .008 is the right setting.
Has anyone worked on this engine recently?

 

[GBJeffOH]

With the valve cover off, bar/turn the engine over and make sure all of the valves (especially exhaust) are opening the same amount.

It is back together. I think I would have to pull the engine to look at the exhaust valves.

 

[North Idaho Wolfman]

It is back together. I think I would have to pull the engine to look at the exhaust valves.

No, with the valve cover off you can see the valves moving.

Take off the pipe going from the intake to the air cleaner and see if you get that same back puff at an idle.

Have you replace both air filters (120 + 110) ?
Have you checked the incoming pipe (150) for blockage?
I've also see hoses collapse and cause issues.