HPDI 150 Noise @ Low RPM

[Twin R]

Couple of weekends ago, while slowing down, the starboard engine shutdown for no apparent reason. When trying to restart it, it would idle but would not take a load plus it was making a noise. This weekend, we checked the plugs, no fouling there.

We noticed the fuel cup seemed low (about at the bottom of the fuel filter in the cup, versus the other engine. We pumped the fuel bulb and it seemed restricted. We changed the spin on fuel filter off of the fuel tank. We got some sediment out of it and when we pumped the bulb with the new fuel filter, it seemed to move fuel easier.

When we started the engine now, it would take full throttle under load, but two things appeared.

One, the fuel cup still does not fill to the top like the other one.

Second, at low RPM, 6 to 10,000, there is a noise in the engine. It sounds like it is around the top of the head. Almost like lifters rattling on a four stroke with cheap gas. You don't hear it at running RPM. We ran about 30-miles and it ran great, but just noisy at low RPM.

Anyone got any thoughts?

SC

[Hamfisted]

You probably need to loosen the filter bowl and bleed the air out of it (pump the primer bulb to fill it and push the air out...). The noise could be caused from air getting into the high pressure pump which is mounted high on the back of the powerhead. Also check the oil level in the high pressure pump itself, there have been reports of low oil quantities from the factory and missed on dealer checks. It uses the same gear oil as your lower unit and should be changed annually or every 100 hours. I use Mobil One 90w synthetic in mine. If you don't have one already go to www.Yamahapubs.com and order a service manual for your motor.


Mike

[Twin R]

Thanks Mike,

I let you know the outcome this weekend.

SC