Onan Gen--hard starting and surging
I was gifted a 95 Bounder 34ft with the big block Ford engine. 30kish miles. Sat a lot. I've resurrected it back to 90% operational. I've made several statewide trips. The generator. At f...
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My unit is a 5000, not a 5500. The carb faces the rear of the coach.
I never could get the brass connection to the bottom of the filter. So I cut the line leading to the filter, from there I removed the filter, blew out any fuel and gunk that might have been there.
After removing the filter from the carb, I pumped some SeaFoam spray down into the carb. Cranking the motor just briefly I could then determine the fuel pump is working...so the line was plugged with a bolt so I could crank the motor without getting a face full of gas.
I got it to start with the inlet fuel line loaded with Seafoam sorta kinda. I opened up the connection to the carb from the air filter, where I sprayed the innards also with Seafoam.
It ran better----smooth, after connecting back the inlet fuel line. UNTIL I put some load on it. Then the surge came back slightly, then got worse and worse until it quit.
I fired it back up, this time playing with the throttle, I am guessing that there must be a FAILSAFE that if the RPM's get too high the unit shuts off. I tried to get the RPM's up higher to see if it would self-clean with some fresh gas from the main tank, but nope...nada.
Opening the fuel line back up I poured more Seafoam into the line leading to the carb, where I let it sit for an hour. Again, it surged and finally quit.
SO.....I guess I will try one of those carbs off Ebay. I see I can get one for about $50-60 bucks. The swap looks easy enough. I am sure if I take it to the Cummins shop they will sell me a new carb at $400 plus labor.
One thing I did do is blocking the inlet gas line with a bolt, I checked after cranking to see if any of the leading gas lines from the main tank were wet indicating a crack. None.
**Footnote** The adjustment at the bottom of the carb for altitude, I have it set at Sea Level. If I turn it to 5000 or upwards the unit really does run rich.
I guess I could try some more carb cleaner, like BG or another product, but it appears whatever is going on with this Genset, the years of sitting in that storage yard has destroyed the carb just enough that it does not want to operate anymore.
I never could get the brass connection to the bottom of the filter. So I cut the line leading to the filter, from there I removed the filter, blew out any fuel and gunk that might have been there.
After removing the filter from the carb, I pumped some SeaFoam spray down into the carb. Cranking the motor just briefly I could then determine the fuel pump is working...so the line was plugged with a bolt so I could crank the motor without getting a face full of gas.
I got it to start with the inlet fuel line loaded with Seafoam sorta kinda. I opened up the connection to the carb from the air filter, where I sprayed the innards also with Seafoam.
It ran better----smooth, after connecting back the inlet fuel line. UNTIL I put some load on it. Then the surge came back slightly, then got worse and worse until it quit.
I fired it back up, this time playing with the throttle, I am guessing that there must be a FAILSAFE that if the RPM's get too high the unit shuts off. I tried to get the RPM's up higher to see if it would self-clean with some fresh gas from the main tank, but nope...nada.
Opening the fuel line back up I poured more Seafoam into the line leading to the carb, where I let it sit for an hour. Again, it surged and finally quit.
SO.....I guess I will try one of those carbs off Ebay. I see I can get one for about $50-60 bucks. The swap looks easy enough. I am sure if I take it to the Cummins shop they will sell me a new carb at $400 plus labor.
One thing I did do is blocking the inlet gas line with a bolt, I checked after cranking to see if any of the leading gas lines from the main tank were wet indicating a crack. None.
**Footnote** The adjustment at the bottom of the carb for altitude, I have it set at Sea Level. If I turn it to 5000 or upwards the unit really does run rich.
I guess I could try some more carb cleaner, like BG or another product, but it appears whatever is going on with this Genset, the years of sitting in that storage yard has destroyed the carb just enough that it does not want to operate anymore.
