Yamaha 250 HPDI Hesitates- why?

[JimGil]

My Yamaha HPDI 2008 Series 2 hesitates when I put the hammer down. It's worse if I am behind another boat (my prop is in the water left by the previous boat). But it's NOT cavitating - it just hesitates. If you don't punch it, but accelerate a little slower it's fine (say, put the hammer down in two second, rather than in a nanosecond. . . )

Once you are on plane it's totally fine.

[Superbender]

sounds like a fuel problem,check vst filters:thumbsup:

[DerStream]

:iagree: VST Filter, change it out if it has not been done in a while, process of elimination. Plus that filter isnt that bad price wise, compared to the EFI Merc one. When you swap that filter you need to change the VST Main Gasket also.

Good luck.

[aguywithabucket]

i have the 09 300 hpdi when i smash mine hard like that it would hesatate for an 1/8 of a sec then roar to life it was almost like a stumble i thought it was cus i was being a prick to it and was tring to ram a **** load of fule down its throat is that is what yours is doing and mine was like that from day 1 and it was new fule cell filters hoses

[Superbender]

i have the 09 300 hpdi when i smash mine hard like that it would hesatate for an 1/8 of a sec then roar to life it was almost like a stumble i thought it was cus i was being a prick to it and was tring to ram a **** load of fule down its throat is that is what yours is doing and mine was like that from day 1 and it was new fule cell filters hoses

If yours was doing it from day one I would check linkage set up tps,I have had on rare occasions had lean injectors but check basics first,linda at Brucatos can always help you out to service those injectors:thumbsup:also check fuel vac at the first filter on the motor

[aguywithabucket]

i just thought it was natural for smashing the throddel to hesitate for a millasecond 4 months ago i sent it out to be ported and milled and lighten it revs at 8000 rpm and is aperinty make 358 hp runs on 110oct fule and it stll seems to hesatate for a millacecond (when cold) i thought it was the nature of the beast

[mcyama]

what type boat? how many rpm does it turn at wot? do you have a yammi prop? what is the est. weight? have you been contacted by your dealer about the foward prop spacer replacment per yamaha?