baker01
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Re: Genny starts, runs rough and then cleans up
Sound like the electric choke is the issue now. Electric choke assembly and vacuum breaker assembly (Figure 8-10). Conduct the following checks and adjustments before replacing a carburetor/choke assembly: 1. Apply 12 VDC across the heater terminals. The choke should open fully in 2 to 3 minutes. 2. Check the heater alignment marks and realign if out of alignment. The choke should be closed at temperatures below 70° F (21° C). It may be partly open above 70° F (21° C), but should close almost completely when vibrated (engine cranked). If your electric choke is closed when hot it sounds like it is out of alignment or not getting power. try step one and see what it does. You should be able to loosen the three screws on the choke to adjust it.851Views0likes0CommentsRe: Genny starts, runs rough and then cleans up
From the manual Electric choke assembly and vacuum breaker assembly (Figure 8-10). Conduct the following checks and adjustments before replacing a carburetor/choke assembly: 1. Apply 12 VDC across the heater terminals. The choke should open fully in 2 to 3 minutes. 2. Check the heater alignment marks and realign if out of alignment. The choke should be closed at temperatures below 70° F (21° C). It may be partly open above 70° F (21° C), but should close almost completely when vibrated (engine cranked). If your choke is open when cold it sounds like it is out of alignment. You should be able to loosen the three screws on the choke to adjust it.446Views0likes0CommentsRe: Genny starts, runs rough and then cleans up
The Onan vacuum pull off is not cheap at $55-70. I tried to match up an automotive/small engine unit and could not find one that would fit. here is a link to a cheap vacuum pump tester http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html You put vacuum to the canister the arm on the unit should suck in and stay in. if it moves back out you have a hole in the diaphragm445Views0likes0CommentsRe: Genny starts, runs rough and then cleans up
Here is a link to a pic of the carb. It is the silver canister upper right side. Onan carb A quick way to check it. Pull the air cleaner element out. you should see the choke plate is almost completely closed (only do this with the gen cold). Start the generator the choke plate should open slightly more but not all the way. If it does not move, open it slightly with your finger. If the stumble stops It is most likely a bad canister or vacuum line going to it. You will have to pull the carb to test the canister.364Views0likes0CommentsRe: Genny starts, runs rough and then cleans up
I had the same symptoms on my 5.5 Onan. Check the vacuum choke pull off. My issue ended up being the vacuum choke pull off. The pull off had a bad diaphragm. The diaphragm can be checked with a cheap Harbor Freight tester. This caused the choke to stay completely engaged until the electric bimetallic spring opened the choke. This caused it to run rough the first few mutes until it warmed up. I replaced the pull off and no more issues. Good luck363Views0likes0CommentsRe: Throttle non-responsive after batter disconnect
Found this 2006 V10 procedure for you A dirty throttle body can cause a low idle condition after disconnecting the battery. The engine computer will "learn" a new idle position over time as deposits build on the throttle body. When you disconnect the battery this memory is lost. The computer should relearn the idle speed fairly quickly. To help it along try the following: Warm the engine (hold the idle up with the gas pedal if necessary). When the engine is warm slowly release the throttle until the engine will idle on its own, let it do do for about one minute. Next with your foot on the brake place the transmission into drive and let the engine idle for another minute. Next with the trans in drive turn the a/c on for another minute. If this procedure does not restore the correct idle for your 2006 Ford F-250 Super Duty you can try cleaning the throttle body deposits by spraying some carb cleaner on a rag and wiping the throttle bore.689Views0likes0CommentsRe: 1986 Onan BFA 4 - Suddenly running rough
Gas, Spark, and Air. I had the same symptoms on my newer 5.5 Onan. Check the easy things first Float bowl: did a piece of dirt get through? Clean out float bowland jets. Plugs: is one fouling? Pull and check plugs. Fuel pump/filter: Is it pumping enough fuel? Is it getting weak after it gets hot? Is a dirty filter restricting flow? Check filter and pump. Vacuum leak: Vacuum leak will cause your symptoms. Check carb gaskets. Check vacuum line going to choke pull off. Check vacuum choke pull off. My issue ended up being the vacuum choke pull off. The pull off had a bad diaphragm. This caused the choke to stay completely engaged until the electric bimetallic spring opened the choke. This caused it to run rough the first few mutes until it warmed up. The secondary effect was once the choke was open the vacuum leak would cause the generator to run lean. Lean caused it to run hot. Eventually it would start to surge and then shut itself off. I replaced the pull off and no more issues. Good luck74Views0likes0Comments
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