Yamaha ProV 150 bogging on take off

[duppie03]

I have a 1989 Yamaha ProV 150 that is bogging on take off, and surges above 4500 RPM. So far I have replaced the water pump, poppet valve, spark plugs, fuel, fuel lines, and put in a Yamaha fuel/water separator. The compression was between 120 and 125 on all cylinders, and I have spark on all my plugs. I'm assuming that its a carburetor problem, but I wanted to see if anyone can think of what I might be missing, or has any other suggestions before I take the carburetors apart.

 

[hall832]

Most likely You need to get Yamaha carb kits, tear down your carbs, clean them and rebuild them. How long have you owned this motor, What kind of fuel do you use, ethanol or rec fuel, Does it sit for long periods of time without being used?

 

[duppie03]

I bought the motor about a month ago, and ran it for the first time this week after mounting and rigging it on my flats boat. I run Ethanol free gas in my boat, could the fuel pumps need to be rebuilt as well?

 

[99yam40]

always a good idea to replace pump when cleaning carbs.
stuff hiding in there can jump out and mess up the just cleaned carbs

 

[duppie03]

I just pulled all the new spark plugs I put in and the lower plug isn't burning like the others. So I did a quick spark test and I'm getting good spark, so I'm assuming this is a fuel delivery issue. Would this be another symptom of dirty carbs/fuel pumps

 

[hall832]

Carbs are easy just make sure to be thorough with every single hole, tube, passage and take it down all the way. Make sure to get the kit and do everything. Definitely use Yamaha Brand. if you miss something on the first rebuild it will drive you crazy.

 

[duppie03]

Just wanted to say thank you...did the carbs myself last night, and the motor runs amazing. Its a really great feeling doing it myself.