small engine problems

[Kook]

I have a generator with a 9 HP Honda engine. Had a batch of OLD gas run through it. It would run fine for while, then sputter and backfire. I brought to a local mechanic/shyster who said it needed a new carb. OK Fire it up, runs fine for 5 minutes, then starts to backfire again. I fooled around with the fuel line to the carb to make sure fuel flow wasn't impeded. Seemed to run OK. Then all of a sudden, it starts to backfire again. Noticed the tank was running low

So, if the fuel was sloshing around in the tank, and carb sucked air, would this be the problem? Or is there something else I'm missing? Engine ran like a top until the bad gas issue. Bringing it back to a mechanic is a last resort, as the generator is at a camp, and finding a friend to help load in the boat is hard to do.
Any suggestions?

 

[jms]

take it back tell the "shyster " to do his job right this time !

 

[jrfount]

Check the fuel cutoff valve that is attached to the underside of the tank. The Honda design is pretty notorious for clogging when old fuel is left in the tank. You can often blow air back up through it to temporarily clean it but once it cloggs again you'll start getting a lean condition and a backfire. Also if they changed/rebuilt the carb but there isn't an inline fuel filter you may have a clogged port in the carb again. Remember a speck smaller than a grain of sand can really play hell on a carb, particularly Honda's. Their intricate carbs give them great fuel efficiency and easy starting but they also suffer more from bad fuel and trash than a simpler carb.

On another note I've only ever had to replace one carb in all my years of working on engines and that was on a Tecumseh because it was designed to be a throw away. IMHO they shouldn't have had to replace the carb on a honda, a rebuild would have been cheaper and likely just as effective. But I didn't see it so I can't be sure.

 

[SVTFreak]

Run some good gas through it first man.

Did he "fix" it? Could be a couple things. One is sucking air. Or draining the bowl of carb and can't refill. That could be either plugged fuel filter, restricted fuel line or sticking needle/seat.

FYI, bad gas won't ruin a carb. Maybe make it need a rebuild but not ruin. Chances are if the bad gas didn't sit in it, was just ran through it, running good gas through it will clean it up.

 

[posse comatosis]

take it back tell the "shyster " to do his job right this time

That's easier said than done. You gonna tell him he screwed it up the first time around and they you're gonna let him have another crack at it? He sees you comin', bro.

 

[Kook]

It has GOOD gas in it now.
Pulled the lines and has good fuel flow.
I cleaned the original carb 3 times before bringing it in. I was so frustrated I agreed to the new carb.

 

[Quickdraw22]

Check your valve lash. If the valves are tight, they will only get tighter as the engine heats up, and the engine will sound like crap and then die.

That *MIGHT* be the problem, and isn't crazy hard to fix.

-Dave

 

[dantheman]

Put a couple of ounces of fuel injector cleaner in the gas , and a fresh spark plug . See if that helps . It's worked for me before .

 

[bearfutedninja]

how is the plug is it properly gaped? was the tank, petcock, and fuel filter cleaned before installing the new carb? its like shitting your pants and putting on a new set of underwear without washing your ass. at the time it sounds like a good idea but next time you take them off there is going to be crap in them