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I have a Honda GX390 engine on a pressure washer. When I…

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Hi I have a Honda...
Hi I have a Honda GX390 engine on a pressure washer. When I test for compression, I get 60PSI. Can it start with that or can I try and adjust valves to get more pressure. If so can you please explain how to adjust valves. Thank you. Also, went to YouTube but don't explain step by step
Submitted: 7 months ago.Category: Small Engine
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Answered in 10 minutes by:
12/7/2017
Technician: JON, Small Engine Technician replied 7 months ago
JON
JON, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1,854
Experience: Certified Small Engine Technician
Verified
Is a compression is not enough to run the engine adjusting the valves is not going to give you any more compression the issue is in the piston and cylinder.
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Customer reply replied 7 months ago
Ok so I purchased a cylinder and piston along with rings. Is there a video for install on honda GX390
Technician: Curtis B., Technician replied 7 months ago
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 31,456
Experience: have worked on and around most engine models for 35 yrs./Polaris ATV expert
Verified

I see Jon opted out. Have you torn the engine down yet? Before you do, check the valves! If valves have zero clearance, it CAN affect the compression. If you do have clearance, it will not. You will not find a video that goes from step one to finish for this repair. The engine has to be removed from the washer and cylinder head removed, then the engine has to be split, to gain access to the connecting rod. A service manual is what you need.

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Customer reply replied 7 months ago
Thank you for stepping in. I asked the other tech if adjusting the valves could help and he said wouldn't help. I personally think they were messed with and need adjusting. I need an informative video to do so. Please help. I will leave tip of appreciation
Customer reply replied 7 months ago
I am now confident that valve adjustment the correct way will be needed though
Customer reply replied 7 months ago
I did both valves at .020 while piston centered
Customer reply replied 7 months ago
Should I cancel the cylinder block and pistons I ordered?
Technician: Curtis B., Technician replied 7 months ago

OK, sounds excessive on the clearance, .006 would be better, but it worked! You don't need the internal parts you ordered! Your compression is fine!

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Technician: Curtis B., Technician replied 7 months ago

Have you tried to start the engine? Do you have spark and fuel? It should run.

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Customer reply replied 7 months ago
After that I checked for spark and was good. I had done a complete carb clean in ultrasonic cleaner and pretty sure all jets were cleared. It did not start. It only wants to start if I use a dropper and put fuel in spark plug hole. Turns on and right off. Not even on for 3 to 4 seconds
Technician: Curtis B., Technician replied 7 months ago

Fuel is not going thru the carburetor, the main jet, which is the bowl bolt and the passage it screws into, is the main jet. Do you have the full flow of fuel to the carburetor inlet from the tank line?

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Customer reply replied 7 months ago
I will take it apart tomorrow morning and see. I will make sure to clean it thoroughly. Thank you
Technician: Curtis B., Technician replied 7 months ago

OK>

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Customer reply replied 7 months ago
This morning I removed the carb and put in the ultrasonic cleaner. What I didn't do last time, is remove the gas shut off valve and clean that. It was completely blocked with with sludge. As that was in cleaner. I tried to adjust valves again to .006 intake and .008 exhaust. Now I have a good carb where I'm getting fuel but now don't even start if I put fuel in spark plug holes. Should I just readjust valves to where I had 120 compression?
Technician: Curtis B., Technician replied 7 months ago

You have to have the compression. I like to set valves, by turning till one valve is compressing the spring (open) and set the one that is up (closed), then once it is set, turn engine till the set valve is open, and the other is closed, Always works with any engine. Then see if you have compression and engine will start.

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