Checking RPM's

[hornblower]

I'll put the question first. Is there an easy way to check the RPM's of a 5hp Honda 4 stroke? Did I mention easy? I'm not a mechanic.

I have a 5hp honda 4 stroke, 2002 model. The motor runs fine, is great on gas but short on power. When I open it up, full throttle, it sounds like it's only running at a fraction of the rpm's that I'm used to hearing from an outboard. When it's in neutral, I can turn the throttle all the way up and it's no where near over revving. Every outboard I ever used would sound like they were about to fly apart if you held it at full throttle in neutral. I took the cover off and pushed on the linkage and it revved way up. Also, I took my 12' boat for about a 25 mile cruise and it only ate about 3/4 tank of gas (actually I think less) after running it full throttle most of the way.

Now I Know that the throttle is set at a safe limit and I should not try to go over that but I think the adjustment may be way off. I assume the best test is to check RPM's, but is there an easy way? The specs say 4000 to 5000 is the range for this motor. Any help appreciated.

Andy

 

[pvanv]

Re: Checking RPM's

To verify RPM, you need a tachometer. TinyTach makes some inexpensive units.

 

[scrampbell]

Re: Checking RPM's

You need to call Jess at globaltestsupply. He's a friend of mine and it's actually his Honda motor that we're trying to fix in the thread I posted earlier today. They have an instrument that all you have to do is aim the laser pointer at the prop and it'll give you a reading in RPM. Hell, tell him it's for your boat and he'll probably give you a discount. Call him at 888-610-7664.

 

[Mas]

Re: Checking RPM's

They have an instrument that all you have to do is aim the laser pointer at the prop

You probably want to aim at some reflective tape mounted on the flywheel...not the prop. A spinning prop needs to be in the water so cooling water pumps to the head...a prop in water is not visible to a laser tach!

MAS