engine not running high rpms

[JMooney]

Hi Russ,

For some reason my 16 hp clone wont run at higher rpms for more than ten minutes or so. I've found a sweet spot at around half throttle and it will run all day there but when I need to turn it up, it just wont stay running for more than about ten minutes, sometimes 3 or four minutes if its under a load surface cleaning. BTW, the engine is new and has done this since it came out of the box.

 

[Russ Johnson]

Sounds like it's wanting more gas than the system can supply. Try running it without the gas cap for a bit...might not be venting properly. If that doesn't work, take the bowl off the carb and see that the float moves properly. Turn the gas on and see what kind of flow you're getting.

 

[JMooney]

The flow is very slow, much slower than the 11hp I compared it to. Thanks for the tip. Not sure what steps to take next. When I removed the float, it started flowing properly but as soon as I put the float back in place, the flow slowed back down. Something with the float needle I suppose.

 

[Russ Johnson]

The float and needle valve must not have been made properly. It's a Honda style carburetor, isn't it? I should have one or two float / needle assemblies laying around. I'll get one to you if you need it.