Genny smoking

Havana Shamrock

Havana Shamrock

Well-Known Member
SILVER Sponsor
Sep 9, 2008
5,422
Sarasota Fla.
Boat Info
2019. 250 SDX OB
Engines
300 Verado V8
last year every once in a while my 5kw westerbeke genset would smoke terribly , this only happened three or four times, other days it would run for hours flawlessly, it smoked so bad once it looked like the boat was on fire. then the next time it was fine???? the smoke was light blue or gray i dont think its an internal problem such as rings or seals could it be a choke/mixture problem anyone sseen this happen before???( p.s. the smoke was out of the exhaust )
 
My owner manual states that WBs will smoke if overloaded (>75% of rated output). Mine smoked when it was brand new. It had a sticky choke that was replaced under warranty. Overloading produces grey smoke. Sticky choke makes black smoke.
 
SB, i"m glad you mentioned the choke i lubed up what i think is the choke linkeage and it didnt happen again for a while i never start it with a load although i prob maxed it out a few times, if it where something more serious say, rings etc. it would smoke all the time you think? it is original 2003 equip but only had 11hrs on it in 2009 could that also contribute to it ?
 
frozen with salt said:
SB, i"m glad you mentioned the choke i lubed up what i think is the choke linkeage and it didnt happen again for a while i never start it with a load although i prob maxed it out a few times, if it where something more serious say, rings etc. it would smoke all the time you think? it is original 2003 equip but only had 11hrs on it in 2009 could that also contribute to it ?
Click to expand...

If you are not using oil, I would suspect the choke. Also, you should run it at least twice a month to prevent corrosion and other issues associated with long periods of inactivity.
 
thanks sbw1 would you know where the zinc is on this gen set ? did you say you had a similar model? i have no manuals for it.
 
I'll look. My manual is on the boat. Should know tomorrow.
 
I had a similar problem once with smoke that looked like she was on fire..stopped the genset
and restarted all was ok..When I first start the genset i always check if raw water is passing through the system .

with my problem it was that raw water would start coming through ok but one the gen heated up whala heaps of smoke. changed the impeller and all was ok.. The damn thing was spinning on the shaft

might be your problem
 
Ozzie-iv said:
I had a similar problem once with smoke that looked like she was on fire..stopped the genset
and restarted all was ok..When I first start the genset i always check if raw water is passing through the system .

with my problem it was that raw water would start coming through ok but one the gen heated up whala heaps of smoke. changed the impeller and all was ok.. The damn thing was spinning on the shaft

might be your problem
Click to expand...
thank you for the insight will check the impeller
 
Joe, I was not able to download the WB manual from the suggested link. If you can do that, the info you requested is on page 14. Essentially it shows the zinc, a pencil anode, on the top side of the heat exhanger adjacent to two raw water cooling hoses that come out the top of the exchanger. It is about an inch from the end. The instructions are to check the anode monthly for wear and clean or replace as necessary. Do not use any sealant when replacing. And, it cautions you to hold the hex boss into which the zinc anode is threaded with a wrench while loosening the anode with another wrench. This prevents the hex boss from possibly tearing off the exchanger shell. It goes on to state that if your anode is in poor condition there are probably a lot of fragments in the exchanger and the end of the exhanger needs to be removed so these fragments can be cleaned out. The exhanger needs to be cleaned by a radiator repair shop at 1000 hours. Hope this helps
 
I took a look at it I'm not sure of my model # the boat is shrinkwrapped but i think the 5kw are pretty much the same. i only have 20hrs on the gen so i hope a little maintenance goes a long way thanks foe your help.
 
What does the smoky exhaust smell like? One whiff will tell you right away what the problem might be. If it has little to no smell, you're seeing white steam and should check for a low water flow or other cooling system problem. If the smell is very strongly of gasoline (smoke color typically grey/black), then check for carburetor problems, such as a sticking choke. I loaned my service manual to Rod, so I cannot quote it right now, but I'm pretty sure that lubricating the choke linkage is a no-no. Clean it and free it up. If the smell is oily (and the smoke is blueish in color), then you need to look at rings, valve guides or the engine breather system.

Follow your nose. Incidentally, you can order the installation, service, and operator manuals from Westerbeke though the web site, or from your local distributor. Distributors are also in the Westerbeke website.

Best regards,
Frank
 
Last edited:
frozen with salt said:
last year every once in a while my 5kw westerbeke genset would smoke terribly , this only happened three or four times, other days it would run for hours flawlessly, it smoked so bad once it looked like the boat was on fire. then the next time it was fine???? the smoke was light blue or gray i dont think its an internal problem such as rings or seals could it be a choke/mixture problem anyone sseen this happen before???( p.s. the smoke was out of the exhaust )
Click to expand...

I'm pretty sure that the Westerbeke on your boat has a carb as opposed to EFI. There are three basic reasons that a carb based Westerbeke will throw black smoke:

1) An improper gain setting whereby the unit "bogs" down when a heavy electrical load is applied (like an AC kicking in). The gain controls the engine's response to the load applied. In a "bogging" scenario, the balance of engine rpms falls out of sync with fuel flow. Most Westerbeke's (except really old models) gain controls are electronic.

2) A stuck choke. This usually occurs on startup when the choke is "set" to reduce airflow and create a richer mixture for the engine. If it does not release, it will produce an rich mixture and black smoke. However, if the unit has been running ok for a while.....I don't think this is the cause.

3) A stuck float or problem in the carb. Sometimes debris finds its way into the carb and causes the float to stick open flooding the mixture with too much fuel. The result looks like a coal fired freight train pulling up a long grade.

How many hours does the unit have on it?


-John
 
The pencil zinc is int the heat exchanger on bottom aft side the heat exchanger...
 
rcknecht said:
The pencil zinc is int the heat exchanger on bottom aft side the heat exchanger...
Click to expand...
Are you sure about that? The manual shows it on the top. If it were on the bottom you would spill raw water into the bilge every time you checked its condition.
 
my pencil was on the bottom of the heat exchanger..had to drill a hole in the timber platform to remove the zinc... I took the end cap off the head exchanger and there were largish chunks of zinc in there which I was able to remove with my fingers.

That still didn't cause the problem with smoking like she was on fire.. when the genny was cold water pumped through the system ok but as soon as she warmed up the water flow only just trickled and then stopped followed by a lot of smoke.
 
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PlayDate said:
I'm pretty sure that the Westerbeke on your boat has a carb as opposed to EFI. There are three basic reasons that a carb based Westerbeke will throw black smoke:

1) An improper gain setting whereby the unit "bogs" down when a heavy electrical load is applied (like an AC kicking in). The gain controls the engine's response to the load applied. In a "bogging" scenario, the balance of engine rpms falls out of sync with fuel flow. Most Westerbeke's (except really old models) gain controls are electronic.

2) A stuck choke. This usually occurs on startup when the choke is "set" to reduce airflow and create a richer mixture for the engine. If it does not release, it will produce an rich mixture and black smoke. However, if the unit has been running ok for a while.....I don't think this is the cause.

3) A stuck float or problem in the carb. Sometimes debris finds its way into the carb and causes the float to stick open flooding the mixture with too much fuel. The result looks like a coal fired freight train pulling up a long grade.

How many hours does the unit have on it?




-John
Click to expand...

PLAYDATE, I only have 20 hours on the unit, the boat was a manhatten boat and was at a marina most of the time so the previous owner never used it. could the lack of use also be part of it?
 
20 hours on a seven year old boat? Is there more to this story?

Sure, you have to use these things on a regular basis. Imagine owning a car that you only drove 100 miles a year for 10 years.

My guess a carb rebuild and replacing the plugs would solve the problem. If the generator hasn't been used the fuel bowl will have a varnish like substance in it that will clog the jet or cause the float to stick open. The light usage would also wreck havoc with the fuel injected version.

Since you are changing the plugs, I would also do a compression check on the generator's engine just so you have a baseline. It will also give you some piece of mind that the cylinder walls are ok (rust damage) and there hasn't been a past problem with water ingestion. Low cylinder compression will throw black smoke if a big electrical load is applied since the engine does not have the torque to handle the load.

-John
 
PlayDate said:
20 hours on a seven year old boat? Is there more to this story?

Sure, you have to use these things on a regular basis. Imagine owning a car that you only drove 100 miles a year for 10 years.

My guess a carb rebuild and replacing the plugs would solve the problem. If the generator hasn't been used the fuel bowl will have a varnish like substance in it that will clog the jet or cause the float to stick open. The light usage would also wreck havoc with the fuel injected version.

Since you are changing the plugs, I would also do a compression check on the generator's engine just so you have a baseline. It will also give you some piece of mind that the cylinder walls are ok (rust damage) and there hasn't been a past problem with water ingestion. Low cylinder compression will throw black smoke if a big electrical load is applied since the engine does not have the torque to handle the load.

-John
Click to expand...

John, the smoke was light blue/gray in color i'm hoping your right some maintenance issues , thanks for the help.
 
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