Yamaha pro 50 bog

" I just found this board lots

" I just found this board lots of good info.purchased 1989 yamaha pro 50 last fall,it had been sitting for over a year.removed the carbs. 3 times and cleaned,motor cranks good and runs good to about 4000 rpm starts to bog, I can pull manual choke out about 1/4 way and the motor picksup and runs good at about 5200 rpm. also replaced primer bulb, gas line and checked fuel pump for hole.have tried to pump bulb running down the water but it is tight.
thanks for any help!!
robertmg "

" Robert,

I'm n

" Robert,

I'm not familier with that engine, but you should really verify that the fuel flow is unrestricted. Disconnect the main supply that feeds the carbs (after the pump coming from the tank), and squeeze the primer bulb; there should be no resistance, the fuel should just flow right through. If that checks out, crank the engine over (with the spark plug wires disconnected) while watching for fuel flow; there should be some type of steady pulse coming out of the feed for the carbs. A couple other things to check for as well; be sure the fuel tank is properly vented and that the vent is open, and be sure that the screen on the tip of the filter that picks up fuel in the tank is clean. If you have a permanent mount type tank, be sure there is not an anti-siphon valve at the fitting; these can stick and reduce flow as well.

Jon "