2005 150 HPDI trouble

[Skyduck]

Can start boat warm up and head down lake fine at any rpm. After traveling several miles (8-10) stopping and fishing when restarting off boat is slow to get on plane and can only get 4000-5000- rpm. 5400-5500 is normal. Park boat return next day all is the same. No alarm, no bucking or jurking, smooth idle.Just no pedal return.
Things I've done... replaced plugs, replace primer bulb, replaced element filter, replaced screen in vst tank, replaced small screen on vst regulator, replaced vst canister filter, replaced mystery screens on hp pump. Pulled lifters from block and pumped bulb no fuel coming out of back of either. None of these things has changed anything.Primer bulb not sucked in, fuel cap makes no difference when opened. I do not have laptop program but thinking something besides fuel is the problem. Any Ideas?

 

[Skyduck]

Re: 2005 150 HPDI trouble

Not that anyone cares, as I got no help here, but maybe the next guy will see. The problem was a dirty 02 sensor. Cleaned it and it's worked fine ever since.

 

[99yam40]

Re: 2005 150 HPDI trouble

It is always best to test things to start out with and then do what needs to be done. Fuel pressure tests will tell you if you need to clean or replace things.
If fuel pressures are good then you know not to mess with that.
If you do not have the tools and equipment to test properly then it is a good idea to buy them or take it to some on that does have them. A Yamaha service manual is the best thing to have to start out with.
I know I am a day late and a dollar short with a reply.

It is best not to run a HPDI with problems untill you know what it's problem is just in case it is running lean as that will get a piston real quick because they normally run on the very edge of lean anyway.