Hi all
I just bought a speedboat with a 115 V4 yam, it starts and runs perfectly but when I open up from idle it runs real rough and almost stalls for a second or two and then takes off like a rocket and runs perfectly. Im using quicksilver outboard 2 stroke oil but heres the thing - I never fully trust an oil pump until I test it so at the moment I am running on the oil pump and a 50:1 premix in the tank (only until I can establish that the level in the reservoir is dropping and all is operating well). Could this be the cause of my dead spot - too rich fuel? I am going to change the plugs also. I removed the plugs on the day but they wernt excessively gooed up also she is not excessively smokey when running but there is a goood bit of smoke at start up. Also she accelerated perfectly without any hesitation on the warm up lever although she is obviously not under load then. by the way I checked compression and its good and even on all cyls.
Any ideas?
Please dont mention a carb rebuilt as I dont want to(I am pretty handy and am well tooled up but I never have before) and the local dealers are almost worse than useless.
Another question doens the oil level alarm work off the under hood tank or the inboard tank on these models?
ya same problem I had. The low speed jets are pluged.
Mine would start fine but rev it up around 2000 and it would stall. I took my bowls off and sure enough they where pluged. I added another filter inline to make sure no dirt at all is getting in and now it works awsome.
It would take ya about 30 min to check the carbs
oh I didnt see that you are runing both pre mix and the injection pump that could be the problem as well. Figure out what you want to run and then take alook at the carbs.
PJ.
I had the same problem not too long ago. It turned out to be a bad fuel pump, the diapham of the pump had a tiny hole in it. At low speed, it flooded the spart plugs causing the motor stalled when taking off. At higher speed it ran fine. I changed a new the fuel pump that solved the proplem. Wish you luck.
yamaha 115hp V4 dead spot
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