Hi idle 150HPDI, what to CK?

[pancake]

Its a 2001 150 HP HPDI Z150TLRZ OK i've run it a few times and still can't get the idle to reduce down to 800/900 RPMS from 1400. Can I get a few suggestions on what to look for or check. If i push on the carb linkage i can force it to lower but as soon as i release the linkage it increases back to 1400RPM. I am running it with earmuffs on and the prop on. I've tried carb cleaner but that didn't change anything.

I spoke with someone who says the engine will run rough and only on 4 cylinders till its put in the water (prop needing some resistance) but my ? is should the RPMS be that high? Shouldn't the RPMS drop when it warms up, is this normal when running on earmuffs out of the water?

 

[rodbolt]

Re: Hi idle 150HPDI, what to CK?

in nuetral it runs on 4 cylinders, once shifted into gear its on all 6, regaudless of muffs or lake or sea.
you need to do several things, one is to hook up the diagnostic test lamp or laptop, most trouble codes lock the timing at 7*BTDC and increase the idle speed.
if no codes are found you will need to do a linkage synchronization, you will need the TPS test harness and a multi meter.
in saltwater we find occasionally a throttle plate will stick, make sure they can all close.

 

[pancake]

Re: Hi idle 150HPDI, what to CK?

thanks for the quick reply. I'm new to Yamaha OB, and was thinking about that it was something i could do like checking the O2 sensor or the vapor separator tank. It seem it requires diagnostic equipment that a backyard mechanic like me doesn't have. This engine hasn't been run for 3 years so i'll probably have to let the dealer fix it.

 

[rodbolt]

Re: Hi idle 150HPDI, what to CK?

just make sure the tech working on it can show at a minimum the school certification on the wall for fuel and electrical.
the winky blinky is about 70 dollars the rest of the test harness about 50 or so.
its not a difficult setup but it does require specific tests.
it also requires the throttle,oil linkage to be CORRECTLY setup or nothing works right, in gear at an idle you will see about 600-650 RPM in gear.
the O2 sensor cannot betested on the flusher, can only be done with the gearcase fully submerged in its normal running mode.
use the yamaha dealer locator to try to find a dealer near you with a master tech.