1979 6V92T Losing RPM

[tdsurfrider]

I have a 1979 43 convertible with twin 6V92T's. Last trip 10 mile run at the end of the trip the starboard engine started to smoke ever so lightly (greyish) and it dropped from 1900 to 1700 rpm's and would not go over that. Ran it this weekend same trip and at about the same point did it again. Stayed overnight, cranked perfectly, turbos spun up fine, ran home and the same thing at the end of the trip. I am new to diesels but from what I gather it maybe an injector sticking. Has anyone ran across this and can point me in the right direction. Another thing to note is i max out between 21-2200 RPM's, but now even when it firsts cranks and runs it will not run up over 1900. Thanks in advance.

[cenger]

Start with the easy suff. Change your primary and secondary fuel filters. It sounds like your fuel flow is restricted.

[Hat43c1981]

I agree with a possible fuel issue causing the symptoms you are sharing. A stuck injector would typically create black smoke that is very noticeable.

I actually have the same Hatt you do but ours is a 1981. Same engines as well.

When was the last time you changed the racors and your secondary fuel filters?

Do you use any fuel additives?

[Captain Ralph]

Darker exhaust is usually not enough air or over-loading.

I think you are loosing boost pressure.
Spinning the turbo wheel with you finger is one thing, loaded, under hot exhaust gasses and trying to compress air, turbos can act very different than expected.
Are you sure the shut down flapper is locked all open?
The last time the air filter was serviced?

[tdsurfrider]

Thanks Yall for the input. I bought the boat back in january, had the tanks polished, new primary, secondary, and racor filters. Had a exaust leak on the way home plugged up turbo filters on that engine. Fixed and replaced the filters back in march. They were in bad shape anyways. I was going to try all the filters first. And I figured thats why it dropped from 2100 to 1900 rpm running. But i didn't understand while after running for an hour or so it would drop even further to 1700. I will check the shutdown flapper. When I replaced the riser gasket on the turbo everything felt tight and spun well. I will double check it but its not smoking until it drops from 1900 to 1700 and its a faint amount of smoke. We will see and I will let yall know.