Under powered 4108 (Fault Finding)

[JulianGullsway]

Afternoon All,

The beauty has covered many hundreds of hours including a trip to Greece from the UK since she had a new head gasket a good 7 years ago, its part of a fault finding process, she seems under powered blowing a slight amount of white smoke out of the exhaust on start up and under load and struggling to hit 5 KTS at 2000 rpm and can only make around 3.5 - 4 kts, shes 11 tonne long keel with a fairly clean bum

I will do a compression test at some stage but wanted to try and tweak the main block nuts under the rocker cover to see if this stopped the white smoke and wondered what type of torque wrench I should use, there is no water in the oil and she starts first time every time..

Thanks Julian

[model 10]

The layout and the way the head gasket seals, water in the oil is not that likely. I have never heard the re-torquing of a copper sandwich head gasket sealing up a leak. Solid copper is different.

[JulianGullsway]

Someone mentioned it to me could there ever be any expansion with the heat etc, any ideas?

Thanks

[DeepFrz]

Have you checked the exhaust mixing elbow? Another thing, when was the last time the injectors were cleaned/adjusted? Maybe a good thing to try if the mixing elbow isn't partially blocked.

[cptcptcpt]

A simple way to eliminate a possible fuel problem is to use a small (vented) container to gravity feed the injector pump. If there is a compression problem then you would have starting problems. While the motor idles try flipping the compression lever one cylinder at a time, should hear change, if not that is a dead valve or ? If you hear suction or hissing when fuel cap is removed then it could be a bad vent. Assuming filters are new.

[CSY Man]

Originally Posted by DeepFrz

Have you checked the exhaust mixing elbow? Another thing, when was the last time the injectors were cleaned/adjusted? Maybe a good thing to try if the mixing elbow isn't partially blocked.

The injectors should be serviced every 400 hours on the 4-108.
Quite a few folks ignore it and run them thousands of hours but the Perkins keep running.
What RPM to you get in neutral at full throttle? It should go up to 4000.

A dirty prop would restrict RPM and cause slow speed, certainly you already checked that..