checking pressure

[brandon32689]

Does anyone know how to do a pressure test and what all I need and how to do it. I would like to do it to make sure my engines are in top notch.

 

[Dr Honda]

A pressure test on what? (fuel system, Pop-off, leak down, compression, jet pump seals, etc)

 

[brandon32689]

The engine I have been told to do it since at beginning of season I had 140psi in both holes and now just 130

 

[Dr Honda]

OK... A compression test. Easy.

1) do it on a cold engine
2) make sure the battery has a good charge.
3) do not add any oil to the cylinders.
4) Install the compression gauge in one of the spark plug holes
5) Hold the throttle wide open
6) Crank until you see max PSI. (3 or 4 revolutions is normal)
7) Repeat in the second hole.


If for some reason it is high... run the engine for 10 ~ 15 seconds, and try again. Extra oil can cause a false high reading.

 

[brandon32689]

I did compression test and got 140 psi in both sides. About a month later it dropped to 130 psi but still runs strong. What I've been told to do is a pressure test to see if the bottom end holds pressure. To see for any leaky seals. But I don't understand.

 

[brandon32689]

anyone else?

 

[Dr Honda]

Thats a leak down test. It's not as easy, and takes some special tools. you have to take the carbs off, and the exhaust. Then, you bolt on block off plates, and pressurize the engine to 10 PSI. If you see a drop in pressure (a few psi in a few minutes) then you have a case or seal leak.

I would say... it's just time for a top-end. Do it before it turns into a full re-build.

 

[brandon32689]

Okay thanks then I will just look into top end maybe I can get threw this season