Its a 115HP OMC/Johnson TurboJet which is actually an OB motor attached to a Jet Drive in a 1996 Boston Whaler Rampage 15. (Don't judge me, it was a freebee from a friend [:-smile_green]). The boat is in great shape and the motor runs fine up to 3000 RPMs, in fact, it seems like it will run all day up to 3000 RPMs. But once you push it past that mark the RPMs drop way off until you back off to idle and then throttle up again to the 3K mark. Then, as soon as you push past 3K it drops off again. Previous owner says the carb has been rebuilt, in-line fuel filter change and fuel lines replaced.. all appears visually to be true. It performs the same way under load and in neutral. I already verified that the oil is in the gas by actually mixing it in the tank rather than chancing on the oil injection pump. So WTH??? It certainly seems to me like a fuel starvation issues but I know little about 2 strokes and even less about outboards. Thanks for any ideas on where to go next... or agaim.
OMC/Johnson 115HP Help!!!
- Thread starter MikeeH
- Start date
Your no load test gives a clue that it is electrical not fuel. Do you have any handbooks from the web that might show a rev limiter or other suspect? They sometimes they have trouble shooting tips. Is it smooth at the max rpm or does it shake?
Wow, electrical?? Never figured that. Yes, its running pretty smooth both up and down the throttle. And, yes, I recently obtained a service manual which lists about 25 different things, some of which are beyond my limited comprehension on this motor. I'll peek at it again and see if there is any mention of rev limiters, etc. Thanks for the idea!
Further research led me to look closer into the VRO (oil injection) system. The service manual said that a loose connection allowing air into the lines can cause the problem I'm having. So I started poking around, tracing hoses and the small hose that I believe carries oil into the carbs actually fell off the hose barb on the carb just as I touched it!! No clamp! I don't have a small hose clamp but I will tomorrow. I'm thinking I may have solved this mystery....hoping!!
Edit: BTW, the VRO system has electric sensors on the carb that sense low oil flow so your initial thought is valid.
Edit: BTW, the VRO system has electric sensors on the carb that sense low oil flow so your initial thought is valid.
GeorgeKohler
Member
- Joined
- Feb 3, 2015
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- 33821
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- 159
Off topic, is that a factory thing or did someone hack that up? I'd love to see some pics of that.