Yamaha (gasp!) question for Bob B.

[Jim in VA]

Bob - thanks for the offline help on the Yamaha VMax 150 (carb). Used some Seafoam treated fuel after swapping out the fuel/water separator filter and gave it a good long run (but not in the range that I was getting slight surge!). After a bit, I went up into the higher RPM range and the motor seemed to behave better. I'll check again this weekend.



In the meantime, I had a chance to max out RPMs at WOT for a short big of the run. I'm running 5200 with the motor trimmed up all the way and on full plane. Can you tell me what the max rpms should be for that motor (2004 vintage)? I'm thinking I should be able to go to at least 5400? I've got a 25P stock prop on now and am going to try a Yamaha 23P prop after I'm sure the engine's back up to snuff.



Thanks!!



Jim

 

[Bob Bourget2]

Jim, that motor should be turning at least 5500 to as high as 5700 rpm. If the motor is "up-to-snuff", prop it down one size. BTW.....put a Merc prop on it...none better.

 

[Jim in VA]

Thanks Bob!! I'll be running the motor some more this weekend to ensure its running well. After that, I'll look into whether a 23P will get me to that target RPM range.



Much appreciated - Jim