Another Yamaha HPDI Issue

[fishnhunt]

So I have once agian developed a issue I can't seem to pin down. At initial startup my motor will die every single time unless I put it in gear and give it some gas via hotfoot. The weird thing is this only occurs at startup when I get to the lake. Once the motor is warm, I can put it in neutral and it will idle like it is supposed too. This is embarrassing at tournament startup when every body is idleing and I cannot because it isn't warm. Other than idle it will get 5800 rpms and runs good.

I have recently changed all plugs and all filters are good to my knowledge. TPS is set at 0.65volts .2 volts higher than spec due to carbon fiber reeds and that spec allows 700rpms at idle. If I set it to .62 volts it idles at 500rpms....suggestion on what else to look at please? Thanks!

its a Yamaha hpdi 250 07

[jdwo2212]

Try changing ball and hose? Does it run if you keep pumping the ball?

[fishnhunt]

I will try that sat I do not know. I do know it doesn't die on muffs only when in the water with back pressure...

[98skeeter202]

When mine done similar it was O2sensor.

[wbrown]

When mine done similar it was O2sensor.

HPDI's don't have O2 sensors.

[mrpontoon]

i have 1 on mine 200 hpdi

[Rich Z]

2.6L hpdi does have an 02 sensor! The 3.3L does not!
Fishnhunt, ensure throttle bodies plates are opening and closing simetricly. Another thing that may help is to have the motor slightly trimmed up during the initial start up to reduce exhaust back pressure.