800 RPM Missing from 671ti's

[Vincentc]

We took a few family members on a slow dinner cruise last night. The engines started and ran fine. Towards the end of the boat ride, I attempted to run the engines up a bit. They would not go above 1400 Rpm. The Glendinning was on and controlled by the port throttle master. At the lower helm, when I pushed the throttle lever past 1400 I no longer felt any resistance from the linkage. The trottle moved freely (too freely) past that point. Several times I throttled back and then advanced, and each time, the throttle felt like it became disconnected from the linkage at half throttle and moved freely, but the engines would not go past 1400. At the dock, with the Glendinning off, the port engine ran up past 1800 in neutral.

Lilly Marie is a 1983 43DCFB with 671 ti's, almost 3000 hours. The Racor bowls have clear fuel. All fuel filter elements changed last summer, 200 hrs ago.

We had a similar problem on an evening ride a few weeks ago, but when I checked things the next day, everything was fine, and the engines ran up without issue. I did notice a stronger diesel / "bug sprayer" smell both times this problem occurred.

Your comments, suggestions, etc will be most appreciated.

Regards,
Vincent
Lilly Marie 43 DC

 

[captddis]

sounds like dirty running gear, I would have a diver check/clean. With 200 hr on the filters it can't hurt to change them all.

 

[Vincentc]

sounds like dirty running gear, I would have a diver check/clean. With 200 hr on the filters it can't hurt to change them all.

Thanks, however I was under the boat a few weeks ago, props etc are clean. Is the loss of resistance in the throttle linkage coincidental with the RPM ceiling not significant?

Vincent
Lilly Marie 43DC

 

[bigbill]

vincent, have someone sit in the e.r. when you run her up. i had this same problem on my 46sf. it was the throttle cable bending at the end where the red cable housing ended. it only affected the throttle when trying to go on plane. bigbill

 

[Genesis]

First thing to do is make sure the throttle lever goes ALL THE WAY to the stop.

If it doesn't, well......

 

[captddis]

Thanks, however I was under the boat a few weeks ago, props etc are clean. Is the loss of resistance in the throttle linkage coincidental with the RPM ceiling not significant?

Vincent
Lilly Marie 43DC

I believe you are on the Gulf coast, believe me a few weeks is enough time to foul the running gear. Make sure it is clean before you drive yourself crazy with other things.

 

[Finalee]

The change in throttle resistance is the clue. Check linkage first.

 

[captddis]

I guess I need to read better. Agree with the others if it will not throttle up at the dock, Ck linkage.