1988 Yamaha 30 hp

[captainppaynter]

I purchased a 30 LG 6J8 1988 Yamaha 30 hp that was primarily operated at 2000' elevation and pushed a 14' Lund @ 35 mph. Prop is 9 7/8 X13. Gas sat in carbs for 3 yrs., & needed cleaning. Now idles great, smooth mid-range and good in the mains until half throttle. From half to full motor 4-strokes & will not pull over 25 mph. I originally thought too rich as I'm at 5000' elevation. Have operated boats here for 30 years & always a little sluggish because of altitude but never a 4-stroke issue. Originally thought needed to re-jet mains but now thinking maybe a bad rev-limiter, if it has one. Friend had same issue on an '89 Force, changed limiter and got his rpm back. I know from the sound of this triple that I'm no way near over-rev. The more throttle I give it from half to full wants to lose even more rpm. My other question is if it were actually starving for fuel would it 4-stroke? The mains are really stuck in the carb but I ran a lot of carb cleaner through them for several hours and blew them out, even though I didn't remove them. Same with pilots but carb cleaner seemed to run right thru. Motor now on 14' Valco, lighter than the Lund. Any thoughts? Capt. Phil

[boats.net]

Run a compression test and check for spark on all cylinders, try pumping primer bulb and or bumping choke to see if helps or hurts it.

[Pascal123]

Working?

hey , i was wondering if you had gotten that motor running good and if not what were you planning on doing with it ? If you would perhaps be looking to sell would you mind sending me an email back ? puma.808@hotmail.com

[bajakeith]

poss fuel restriction

below the intake of fuel pump install a clear hose and T in a vacum guage..over inches 3' means a restriction and lots of air bubbles means a leak some where....K&T