Smoking 20 kW generator

[Docs Holiday]

Can anyone recommend a good diesel generator man/facility in Portland, Maine ? Gen smoking and black soot on side of boat.

 

[Glory]

Have you checked the air filter?

JM

 

[MikeP]

+1 on checking air filter/air intake for obstructions

Further...What brand of generator? If NL, they have an air filter that can be sucked into the intake manifold and block the air intake. THis is not uncommon and is one of the first suggestions after dirty air filter from a NL tech if you have the symptoms you describe.

FWIW if the filter on an NL gets clogged/dirty, it WILL get sucked into the intake manifold runner. IMO the filter material/airbox portion of the manifold is kind of a dumb design on an otherwise really good engine/genny.

 

[Docs Holiday]

It is a 20kw Onan year 1989. I checked the manuals. It does not have an air filter...just an air silencer whic I checked...no obstruction. The boat sat for 19 months and I am on the second tank of fuel so I will change the fuel filters for a second time.

 

[Docs Holiday]

No glory. I changed primary and secondary fuel filters....could this be a valve adjustment problem or injector gummed up problem?

 

[Boatsb]

No glory. I changed primary and secondary fuel filters....could this be a valve adjustment problem or injector gummed up problem?

Not to be a believer in miracles but you could be gummed up enough to have this problem. I'd drop in 2x the required optilube summer plus (cleaner and lubricant with cetane boost). I use this in florida all the time and have found it clears up alot of engines.

 

[Glory]

I'm not thinking injector(s), but to check you could crack each injector one at a time while crew watches for a change. If you find a suspect cylinder you could swap that injector with another abs see if the issue follows the injector or remains in the same cylinder.

After the swap, if you get that far again crack the injectors.

The injectors can cracked at pump or injector end of the line which ever is easier, but do all at the same end so the responce interpretation is fair.

JM

 

[bobk]

Not to be a believer in miracles but you could be gummed up enough to have this problem. I'd drop in 2x the required optilube summer plus (cleaner and lubricant with cetane boost). I use this in florida all the time and have found it clears up alot of engines.

Why not put it in the Racor. I seem to recall listees doing that with the mains.

Bobk

 

[Avenger]

Does the generator perform correctly otherwise? Makes power, holds frequency?

 

[Docs Holiday]

Everything else with the generator is ok. Starts easy. Powers all systems and 14.20 v charging. No misfires or change in rpm. I checke temp. With gun one part of motor 212 deg..rest running 185 to 195. Water outflow looks adequate. I recently replaced the impeller (1 month ago) when I got boat out of storage

 

[Avenger]

Is the smoke white, black or blue? Does it smoke all the time it's running, or only under load?

Does the smoke color change between loaded and unloaded?

How many hours, and when did this problem first occur?

 

[Docs Holiday]

Starts white smoke within minutes of firing up and is putting black smudge on boat behind the gen discharge pipe.. Smoke does not change volume or color when under load. I noticed some smudge prior to putting boat up for storage but the white smoke became more apparent in the last week. It looks like steam to me which is why I checked the block with temperature gun. At one point I got a temp. Of 212 deg. We have been stuck on a mooring here in Boothbay, Maine in thick fog for the last 3days so I'm not able to get boat to Portland to have generator checked out.

 

[34Hatt]

Just listen to Scrod and all will be good !

This is from personal experience
More than once!

 

[captddis]

Starts white smoke within minutes of firing up and is putting black smudge on boat behind the gen discharge pipe.. Smoke does not change volume or color when under load. I noticed some smudge prior to putting boat up for storage but the white smoke became more apparent in the last week. It looks like steam to me which is why I checked the block with temperature gun. At one point I got a temp. Of 212 deg. We have been stuck on a mooring here in Boothbay, Maine in thick fog for the last 3days so I'm not able to get boat to Portland to have generator checked out.

i would also consider a failed exhaust elbow ingesting water.
Funny, I was in Boothbay from Friday until Monday morning.

 

[Avenger]

Thanks Dan. No pressure right?

If it's white smoke and not steam it's either timing, compression or injectors. You could certainly try what Glory suggested and try to isolate if there is one injector that went bad on you.

It would seem odd for them all to go in a short timeframe like you describe. It could be a fuel issue i.e. contamination. Fuel being a couple of years old shouldn't be a problem.

Other than that there probably is not much you can do where you are. I called a friend in Maine and he recommended Lee's Marine & Gear. 207-882-6757.

Hope that helps.

 

[Docs Holiday]

Thanks all for your help. The fog lifted and we got to Portland yacht centre repair yard. An excellent mechanic (Dan), took a quick look, put his hand on the output side hose of the impeller pump, turned around and pulled seaweed out of the intake strainer... Apparently there was enough to block flow though it wasn't obvious from looking at the generator exhaust. I just cleaned the strainers before leaving Eastport, Maine but must have went through some in the fog ! Needless to say, I checked and cleaned all the strainers. I can say this is a great repair facility, not a marina....they didn't even charge me.

 

[Pascal]

Glad you got it figured out, the nest spot to check for temperature isn't the block but the thermistat housing if accessible, or the coolant hose near the tstat.

You can often hear when a genny is running with reduced water flow, the exhaust sound is less muffled.

In addition to the strainer, the other thing to check are the seacock, the pump discharge outlet and the heat exchanger inlet. I ve had all three causing issues in the past few weeks! With th strainer open, opening th sea cock will let you make sure nothing is stuck at the sea cock by watching th water flow in. When epoxing an impeller always make sure you find all th bits which can get stuck in the raw water pump outlet or at th heat exchang inlet.

 

[Docs Holiday]

Again, thanks to all for the suggestions. At the very least it kept me occupied while I was sitting in the fog. I will be posting details on our blog. Www.cruisingwithdoc.blogspot.com for those of you who might be interested or stuck in the fog. Captddis sorry we missed you (we probably passed in the fog!)