GX160 hard to start

I have a 5.5 hp honda GX160 engine that is hard to start, but once it gets going it appears to run solid unless you throttle down quickly and then it sometimes will stall out. I have let it run for several hours and then try to restart and may have to mess with it for 15-20 minutes to get it going again. The engine is 13 months old and runs a salt spreader; when under load it runs ok. Total hours on the engine can't be more than 20. The air filter had some oil on it,and I changed the plug even though it didn't appear bad other than carbon build up.
Thx for any help
jim b

 

drop the float bowl , drop the fuel seperator bowl. check the main jet for a blockage.. if you see any water in the fuel bowl or seperator that may be the problem. also make sure your fuel filter is ok

 

Thanks for the suggestions. I dropped the bowl and cleaned the jet and replaced the filter with the same problem. I had it running this afternoon while driving I hit a bump and the engine quit. Could the problem be the oil switch. If it could how could I jumper it out? Could the coil be giving me an unpredictable charge, and therefore difficulty in starting?
Thx for your help

 

yes it could be an oil alert problem. it happens... disconnect at the wire that goes to the kill switch after you have made sure the oil level is ok. the oil alert switch is really just another kill switch and they do fail. that's usually the first thing i do on a honda. not because it is a chronic problem, but because it is easy to check. and for your use, not worth replacing. by your last post i still think yo have something in the carb. check the cross driling in the main jet again and completly flush the fuel system. add an inline filter while you're at it. that gx motor is one fine machine and is what i spec on any new rental equipment when possible.

 

I removed the carb and cleaned three times, with no success. Finally I replaced the carb(and gaskets), replaced the coil, the plug, air filter, and flushed the gas tank three times. Could get it to start with the pull cord on occassion, but only once with the electric start. Also unplugged the oil alert system. Could it be compression and if so is there anything I could do about that. Getting frustrated.
thx
Jim b

 

check your valve clearance just to rule it out and then get a compression reading. if you can bum a leakdown tester that would help.

 

The problem you're having can be difficult to diagnose, but it's usually something simple. It could be a valve clearance problem, but not likely. It could be a coil, but I'd check other things first. Look at the plug wire and see if it is chaffed or burned somewhere, and the kill wire too. Try unplugging the kill wire from the coil and that will eliminate the kill wire, switch, and low oil sentry as culprits. If it works fine with the kill wire removed, then it's a problem with one of those things. It could be a fuel related problem....like the gas cap not venting. Try loosening the gas cap when it begins to die and see if it straightens out. I don't think that's it because that wouldn't be affected by throttling down quickly, but still worth a check.

It could also be a valve seat loose in the head. This will usually let an engine run when cold until the engine warms up and the head expands and lets the seat work loose. Then the engine usually pops and spits and backfires. Usually it will come out of the head eventually and get hung up and stop the engine until repaired, or it will break something. That doesn't sound exactly like your problem either, but possible.

Try it with the air filter removed, even if the filter looks good. See if that makes a difference.

Lots of "could be, but probably not" things to check, but that's the kind of problem you're having.

 

Thx for your help. It turned out that the cable from the truck cab that plugs to the engine had a splice that had gotten some moisture and was causing a less than solid ground which allowed it to start sometimes and once started evidently not sufficient enough to cut out the engine.

 

Glad you found it, and thanks for the update!