Yanmar 3JH2LTE 25hp White smoke at startup

[stevenagodfrey]

Good day,

I have Khohler 13KW generator on a boat with a pair of 6CTA’s. Generator has 2200 hours and produce a lot of white smoke at startup and excess diesel is visible in the water. I am certain it is not water vapor.

I have tried a number of easy things and followed the service manual trouble shooting.

Engine starts immediately – no knocks or shudders. Smoke continues for about 4 minutes if I put the genset under load and after 4 minutes there are still trace amounts of white smoke and a distinct smell of fuel with some fuel in the water.

Oil is clean – no black like the 6CTA’s. Coolant appears normal and level stays constant,

(0) New air filter, oil change, new fuel filters.

(1) Added block heater – no change

(2) Yanmar trouble shooting suggested a thermostat change – it was $14 so I did that – no change

(3) Removed injectors and attempted to service, but was unable to get apart. Cleaned them and put them back in – no change.

After cleaning injectors engine stared right up. Cracked each fuel fitting and did not hear much of a change on the Cylinder 1 and 2 – engine seemed to “change” more after cracking cylinder 3.

(4) Found replacement injectors for a reasonable price $45 each – replaced

 

Upon removal of the old injectors (that had been recently cleaned) – injector 1 and 2 very little black soot – injector 3 was black. Started to suspect issue with 1 and 2  

New injectors installed – No change – white smoke at startup

(5) Barred over engine – seems inconsistent – some part of cycle more difficult – other sections seems that there is less resistance 

So at this point of I have invested a lot of time on white smoke research and a some money on parts. I suspect I am dealing with a worn engine with one or two cylinders with low compression resulting in the smoke while cold.  The Yanmar service manual describes adjusting injector timing but that is beyond my comfort level and don’t think that is wise without a better root cause analysis.

Are there any simple things I have missed?

Starting to think that I should just start the generator away from the dock while up on plane! However, I want to fix if it is easy,

Thanks in advance

Steve

 

Topic

[stevenagodfrey]

Compression Test Results

Thanks again for the guidance. Valve clearance to spec per Khohler / Yanmar docs. Compression test cold 285, 250, 250.

Next step leak down or is the acceptable and pointing to another issue.

[stevenagodfrey]

Thank you for the ideas.  Yes after changing injectors yesterday I loaded it up with all 4 ac units, chargers, lights, microwave, boiled some water.  No stall but you could hear a little strain

[willyok]

Im not terribly familiar with that model. I would check your valve adjustments then follow up with a compression/leakdown test before throwing anymore parts at it. Will the generator still carry the full electrical load capacity without issue?

[Author]

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