IP 420 4JH3TE idling speed

At idle, the 4JH3TE on my IP 420 (#79) revs at 1100 RPM. I note in the Yanmar service manual that slow idle should be at 700+/-25 RPM.

When I tried to slow the revs by adjusting the injector pump end of the throttle cable, the lowest I could get to was about 900 RPM, but even at that level it would not reliably idle or start.

My question: What are other IP420 owners seeing with their engines - similar to mine, or closer to the 700 RM level?

Neil
S/V Galatea

I do not have a boat like yours, but I would check tach accuracy before I did anything else.
I can tell you many stories of people pulling their hair out trying to get an engine within tolerances, only to discover much later that the gauge was the only problem, engine was fine.
If nothing else I think docking a boat whose engine was really idleing at 1100 RPM, would be interesting

I have 420 haul 52. Never worried about rpm on tach, as long as it is going in and out of gear with know problem.

That being said mine is about 900 by the tach. I never used a timing gun on it to see how accurate it was