2008 HPDI acting up

[briansgi]

Guys, I have a 2008 250 HPDI series 2 with around 10 hours on the motor. I don't use it much, but the last couple days I've had an issue like the motor is not running on all cylinders when I punch it to get on plane. It's intermittent, usually occurs after I've ran the boat for several minutes, stop for 30 minutes and fish, and then start it back up and punch it. I can usually feather the hotfoot, or put it back in neutral, shut it off, try again and eventually it will run great and get on plane and off I go. Is this a classic case of plugs getting fouled? If it is, is it normal for the fouled plug to "clear" itself and then start firing ok? Once my oil level is down I'm going to switch to a full synthetic like Amsoil injector oil. Should I change out my plugs and see if that helps? I don't think it's a case where it's getting too much oil cause it doesn't smoke at all.

[tschooler1956]

When at idle in neutral the engine is only firing on four cylinders, shifting into gear has a switch that tells the engine to fire on all six. Have heard of some problems with the switch. Some one will be along here that knows more about it than me but that would be something to check into.

[Rich Z]

Check plugs first. They should all look the same. If any are darker then others I would suspect injector is firing too much fuel. I have flow tested new injectors before that were flooding. Also, check all plug connections to coils. Sometimes a bad connection can cause headaches. Good luck!

[Hardhead1]

take it to a dealer, still under warranty.

[briansgi]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hardhead1 &raquo;</TD></TR><TR><TD CLASS="quote">take it to a dealer, still under warranty.
</TD></TR></TABLE>

I had a similar issue after I bought the boat, although then it would not even start unless I gave it a bunch of gas, and even then it ran like crap. I took it to the dealer and they had it for 3 weeks and ended up putting a small scratch in it plus it was filthy when I picked it up. It was delivered to them spotless as I tend to keep my stuff. So I'd like to figure this out and fix it myself if it doesn't cost too much instead of taking it back to the dealer again. Besides, my dealer is brand new to Yamaha's and have little experience on them. When they had the boat previously they said they did a slight TPS voltage adjustment and a few other "minor" things. But obviously it's doing pretty much the same thing. I think I'll change the plugs, check that oil linkage adjustment and see if it's putting out too much oil and then switch to Amsoil injector oil too. I'll check the other things that were suggested as well.

[frogfishin]

I think the best move you can make is get your engine broke in first then quit using yamalube, your engine will run alot better .

[briansgi]

I posted this in another forum and someone responded and I believe had the answer to my issue. He said with a hotfoot, which I have, on the HPDI's you have to move the shifter to full throttle position to ensure the switch is engaged to tell the computer to fire on all 6 cylinders. I was not doing that, in fact I would just barely put it in gear. That explains why my issue was so intermittent and at times when I had the issue, I could pull it back to neutral, move it back in gear and it would run fine. So apparently I was not allowing that switch to make contact. It's my first hotfoot so I had no idea I was suppose to move the shifter to full throttle position, but I will from now on!

[OkieBoatMech]

IM sent.

[tschooler1956]

I just have to put mine in gear not full throttle and the shift switch has the engine running on all 6, I have a Hot Foot also. The shift switch might be not adjusted right. I dont touch the Hot Foot on start up.