(151 psi)/600 rpm for Honda 10 hp?

[Mas]

I did a compression check on my Honda 10 HP 1983 era for kicks. The compression looks great...about 125 psi on each cylinder. When I consulted my OEM manual, it stated the "standard compression" should be "(151 psi)/600 rpm."

In comparison, my psi is now looking a little low...but should psi drop 25 at lower rpm?? I do not think I can achieve 600 rpm on a recoil starter ....or am I reading into this wrong?

I'm not thinking anything is wrong, and certainly the motor is no longer new, but 25 psi seems like a big difference.

MAS

 

[JB]

Re: (151 psi)/600 rpm for Honda 10 hp?

Differences in guages, technique and conditions can make as much as 50psi difference in what is measured.

125psi is just fine for a matching pair of cylinders.

 

[Mas]

Re: (151 psi)/600 rpm for Honda 10 hp?

Yes, I'm confident that my compression is good...just wondering if 600 rpms is really required.

Again, no issues...just wondering.

MAS

 

[gss036]

Re: (151 psi)/600 rpm for Honda 10 hp?

The only way to achive 600 rpm is to start the engine and pull one of the plugs. think the hOnda would run on just cylinder.

 

[Mas]

Re: (151 psi)/600 rpm for Honda 10 hp?

I to get it running I would have to run fuel through the carb & there would be a lot better chance of gas getting into my gauge...which I really do not want to do. Maybe hooking my 1/2 inch drill motor to the flywheel nut.

Again, I really do not care. My motor runs great...I was just trying to get clarification.

MAS

 

[gss036]

Re: (151 psi)/600 rpm for Honda 10 hp?

No! You don't want to do that. You do not need to have 600 rpm to check the compression. Remove both plugs and insert/screw the guage into the hole and pull the started cord adn few times. That will give you a compression reading. Then repeat in the other hole.
If the motor is running good, why are you trying to fix something that is not broke.????????????????

 

[Mas]

Re: (151 psi)/600 rpm for Honda 10 hp?

.If the motor is running good, why are you trying to fix something that is not broke.????????????????

I'm not trying to fix anything, I was just curious why Honda would list psi at 600 rpm. It implies to get an accurate reading, one would need to achieve 600 rpm...which does in my mind make any sense.

Trust me, I'm doing my compression the "old fashion way"...with the recoil starter.

I thought somebody would know why it was listed with an rpm.

Just trying to understand Honda!

MAS

 

[hondon]

Re: (151 psi)/600 rpm for Honda 10 hp?

I do'nt know why Honda did that but they have since stopped.As long as those compression numbers are compairablble and not deploreable,say less than 130,you should be good.