2.5hp smoke at high RPM

[Patricknoreau]

Brand new 2.5hp (5 running hours)

1. When throttle is slightly above the orange line, no problem.
2. If throttle opens more than 20%, the following happens:

a. Sounds/feels lazy
b. After 15 seconds engine starts to smoke (blueish)
c. Fuel starts trailing behind the canoe/engine
d. If I bring the throttle down below 20%, smoke and fuel leak stops.

3. It seems like it could run forever if I kept the RPM under 20%
4. I opened the hood when I returned home and it seems wet with fuel all over/around the engine.
5. I only use premium fuel with the Yamalube fuel additive.

Any takes?

[zenoahphobic]

Sounds like the needle and seat leaks when the fuel pump increases its output with increasing revolutions. Fuel gets more into the engine as the throttle slide needle opens the flow from main jet.
It should be pretty easy to pull the bowl off the carburettor and inspect the movement of the float and needle and seat. It probably preferable to take the carby off, disassemble and clean thoroughly although the engine has only run 5 hours. The contamination, if there is, could come from assembly fragments, or water and fuel line breakdown using E fuel.

[zenoahphobic]

Or I could be completely wrong, the fuel pump seal and diafragm is leaking allowing fuel into the engine and outside the engine. Again probable causes diafragm deterioration from causes same as above.

[panasonic]

Check your oil level as well...if flooding that bad it may have gas down in the crank case. I would not touch it..bring it back to the dealer and have them fix it. If you go fooling around with it they may say you voided your warranty.

[brian3006]

For sure..brand new, with only 5 hours on it...take it back for warranty

What a tiny little motor. I literally have a chainsaw that makes more HP than that LOL

[Patricknoreau]

Brought it to the dealership and they fix it. They said the engine oil level was too high. Apparently thats what was pissing through the exhaust.

[99yam40]

the main question now is why was it too high?
did someone over fill it or was the oil diluted with gas somehow while the motor was running?

[panasonic]

How are you transporting your engine when it's off the boat? You owners manual should tell you how to position the engine...on its right side side, left side..ect. or maybe its don't matter. I know 9.9 and 15hp four stroke need be a certain way so oil doesn't get into the cylinders. Yours with the gas tank on top maybe somehow fuel is getting into the crankcase when it's on its side. Just guessing now. Somehow the oil level got to high, either too much was put in or gas is getting in there.

[zenoahphobic]

Yes there is still a question about what caused the overfill. Monitor your oil level as there still is a possibility fuel is leaking - what was the inside under cowling mess, you said fuel? How is that consistent with oil getting into the combustion chamber?