Generator troubleshooting help !2009 Westerbeke 5kw (gas)

Obaby · Post by **Obaby** » Sat Feb 26, 2011 3:42 pm

Problem:
Generator shutsdown after 1hr, restart-then dies after 20 min , then 5 min, then wont start. (non-loaded or under full load )

Non-Issues
1. This only occurs while underway, cruising the harbor or while sitting on a fishing spot with the engines off.

2. It's not a heat related engine room problem !

3. NO power quality issues at all, runs perfect then dies as stated above.

**I can run the generator 5 or more HOURS straight WITHOUT a problem at the dock. ** I cant duplicate the shutdown for my mechanic.

$900 in Mechanics failed services.
Replaced all sensors- Water Temp,Oil Temp, Exhaust temp
New Muffler when installed two years ago...
New strainer, sea cock and hoses.
Replaced Raw Water pump
Replaced Fuel filters, changed oil
Pulled the carburetor and tested

Anyhow , my mechanic is stumped
Any suggestions guys...???
Thanks
Patrick

Paul · Post by **Paul** » Sat Feb 26, 2011 4:11 pm

Possible fuel restriction at the pick up or anti-siphon valve. I've seen this same effect on a main engine for this reason.

Big D · Post by **Big D** » Sat Feb 26, 2011 4:35 pm

What Paul said. Also make sure your choke is working properly and not acting up intermitently.

prowlersfish · Post by **prowlersfish** » Sat Feb 26, 2011 6:43 pm

Any chance it shares the fuel pick up with the main engine ? also check your fuel tank vent if its partly plugged the added pull of the main engine may cause a slight vacuum in the tank that the genset fuel pump can not over come .

Big D · Post by **Big D** » Sat Feb 26, 2011 6:57 pm

Curious, when you say it runs fine at the dock, is shore power plugged in? By your post, it seems to be the only time it works is when you may be plugged in. If so, this may take us into a different direction. Have you ran it at the dock with no shore power hooked up?

davidsmith · Post by **davidsmith** » Sat Feb 26, 2011 7:39 pm

Sounds like ignition coil or condenser to me.

rbcool · Post by **rbcool** » Sat Feb 26, 2011 10:18 pm

Patrick, you obviously have read my posting from the past on the very same problem. Mine will run for days if I let it at the dock, but when out after running for awhile it will only run for 10-12 minutes then crap out.
When I bought the boat I noticed the PO had installed a small in-line blower above the Genny (you can see it in my pics) with a hose that sucked air from the bottom of the bilge and dumped it directly on top of the points housing. While going through all the paper work included with the boat, I came across several pages of copied e-mails from an engineer from Onan suggesting that the condencer was getting too hot.
There was also a couple of reciepts from a mechanic who had replaced almost EVERYTHING on the Genny, including new carb, fuel pump. It looks like the only thing original is the block.
I did a test while fishing one day....... I pulled the hatch up directly above the genny and sure enough it ran for 4 hours while trolling at 3mph and continued to run all the way back to the marina (1 hr @ 22mph)
The next weekend it would not run with the hatch in place. I know this sounds crazy but Hey!!!!

Ron

Obaby · Post by **Obaby** » Mon Feb 28, 2011 6:40 pm

Big D wrote:Curious, when you say it runs fine at the dock, is shore power plugged in? By your post, it seems to be the only time it works is when you may be plugged in. If so, this may take us into a different direction. Have you ran it at the dock with no shore power hooked up?

I tried it both ways , plugged and un plugged. I feel like an idiot I cant duplicate the problem.. I'm thinking a fuel related problem like the others stated.. Thanks

Obaby · Post by **Obaby** » Mon Feb 28, 2011 6:51 pm

prowlersfish wrote:Any chance it shares the fuel pick up with the main engine ? also check your fuel tank vent if its partly plugged the added pull of the main engine may cause a slight vacuum in the tank that the genset fuel pump can not over come .

Paul, I'm thinking the same thing. Both engines and the new generator share the same main tank. The VENT is clear ! My engines and generator are only a few years old, every hose and connection is new. I do have a seperate pickup (3) for each.
Sitting on a calm fishing spot for hours it still shuts down.. I need to see if my anti-siphon valve might be causing this, why I dont know but it's got to be something.. I've even opened my fuel cap and that didnt help..
I'll let you know what I find this weekend..

Thanks
Patrick

Obaby · Post by **Obaby** » Mon Feb 28, 2011 6:55 pm

Paul wrote:Possible fuel restriction at the pick up or anti-siphon valve. I've seen this same effect on a main engine for this reason.

Paul, that's the consensus. Everything was new at repower but I need to check if the anti siphon values were replaced. I'm going to give it a shot and replace all three regardless.

Thanks
Patrick

Big D · Post by **Big D** » Mon Feb 28, 2011 9:52 pm

Patrick, when it runs for hours, does it by any chance coincide with filling the tanks with fuel....you do know that the pick up for generators tipically sit higher in the tank so you don't inadvertently use up all the fuel on the hook and leave none for a return trip? Depending on the manufacturer, it may cut out at half tank. Probably already considered but just in case!

prowlersfish · Post by **prowlersfish** » Mon Feb 28, 2011 11:02 pm

Big D wrote:Patrick, when it runs for hours, does it by any chance coincide with filling the tanks with fuel....you do know that the pick up for generators typically sit higher in the tank so you don't inadvertently use up all the fuel on the hook and leave none for a return trip? Depending on the manufacturer, it may cut out at half tank. Probably already considered but just in case!

Good thought , the pick up tubes are normally a little shorter also I lost a engine a few years back do to hole in the pickup tube . The don't run on air