Honda engine on older lawn mower. Starts then stalls.
 

Honda gas engine on older small lawn mower will start ok then shut off. I've had the carb apart twice,no dirt,clean.Needle looks good not new though. Float has drop,then is flat when flipped over. New fuel. Have brand new mower that runs fine. So I took new plug and placed in older mower same results. Checked gas cap seems ok. Even tried running with loose cap same results. Havent done anything with electrical. I know I could junk it but I want to find out what is going on. It's for trimming in rough areas plus its light and chassis is in excellent condition. Would advance spring on carb be culprit?

How long does it run before it stalls? Does it have spark when it stalls?

Small engines can be a PIA.

Murf


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drop the fuel bowl, clean the screw that held the bowl on, it has a small hole horizontal near the bottom.

It almost stalls immediately then I pull once it fires up does same. The nut is metal not brass so i didnt look close at it. Just sitting checking weather I watched video on you tube about cleaning out nut. So out I go to check it. It's funny that the plug is sooty and when I checked it yesterday was wet. I'm thinking electrical breakdown but not sure. Thanks

The nut is solid no holes. I have ckd fuel delivery seems steady. Thinking hose was crushing. Either its spring on advance or electrical. I'm going to try spring off new mower since it works.Looks same length just less coils.guy on net recommended spring change from one of his videos. I want to learn how and why.

https://www.amazon.com/Lisle-20610-I.../dp/B0002STSC6

LISLE 20610 the short plug wire comes off the bulb housing and you can flip it around for 90 degree
or use it for a straight in style plug wire,,, worth the extra couple bucks over the cheap ones


this is always my best buddy when I have similar issues ,,,

spark
fuel
compression

Last winter I helped a neighbor with his old wood splitter been sitting a year.
Would start and stall.
After flushing old 87 octane(7% ethanol here) from tank, line, and carb, it started, but idled ruff, and die rite off idle.
Finally found fuel line was mushy and collapsing inside.
Keep telling everyone around here use 89(midgrade) in your lawn and garden tools.
Especially 2 cycles. I've had no starting/running problems for several years. And it stores well for 6-12 months. Here anyway.

Hmm gas line ,huh I just checked fuel flow. I'll remove and replace... thanks another base covered.

Yup sounds like another case of alcohol abuse. Ethanol fuel has to be making small engine shops a ton of money. Yank the carb again and blow out every port you can see with carb cleaner. Mechanic in a Bottle has worked for me too, https://b3cfuel.com/product/mechanic-in-a-bottle/

https://www.youtube.com/results?sear...+engine+saloon

This guy has a lot of great vids on small engines.

I run non ethanol 87 octane gas in all my small engines. I can let them set during the off season and they crank right up when I need them. But, my "off season" only lasts about two-three weeks! :D

Thanks again. Yes I pulled up the 'saloon" guy very helpful. He said about stalling and chugging the spring needs replaced. We ll see. Try to get spring today locally.

FWIW, I had a Honda clone engine on a generator that was giving me fits doing the same thing, starting and running out of fuel.

Looked at everything in the carb and had it off and on probably 10 times. I finally found a partial blockage between the inlet nipple and the needle and seat that would let it fill the float bowl, so it would run until the float bowl emptied, and then run out of fuel. It's such a small area, maybe 1/2 inch long total, but it has a 90 degree turn, and that's where I finally found the blockage to be.

It took a bit of troubleshooting to find it, I blew air through it and I didn't see what finally came out, could have been dirt, or even something left in the carb during machining. Low hours and ran fine for probably 8 hours on the hour meter. The engine always had a fuel filter on it, so hard to figure out where it came from.

I blew the inlet, out with carb cleaner. Then blew air both ways. Clean. Just read on net something I've never heard of,to much oil in crankcase can case a problem. The oil goes into combustion chamber,drain some out. Thanks for all the ideas.

Pulled carb back off late last night and disassembled it. Looked closely at all passages. Clean. What I didnt know was the brass tube above main jet is suppose to come out with jet. It didnt so I pried where it came into housing very carefully,it finally came out. Its has alot of crude,small orifices clogged,so today clean throughly and try. Live and learn

My Dad had a Honda push mower that I was replacing a part on and had to take the air cleaner off. I tried to start it and no go. Checked and had spark and fuel still wouldn't start. Finally I put the air cleaner back on and it fired right up. Took it back off to verify and no start again. Would only run with it on.

After all the cleaning. Worse,runs for 5 seconds. Geez back to start. Got only carb gasket dealer had. Place on a back burner for awhile. It's got to ge something simple.

Bob, the replacement carbs for most of these engines are pretty cheap most times, unless you have something that is rare, or extremely old. You might want to just buy a new one and ease your stress level.

Amazon has them for mostly under $20.

Link: https://www.amazon.com/s?k=honda+sma..._sb_ss_fb_1_23

E Bay has then too:

https://www.ebay.com/sch/i.html?_fro...etors&_sacat=0

If you still want to fix your's, these brush and needle cleaning kits work well:

https://www.amazon.com/Carburetor-Cl...-garden&sr=1-2

I have a fuel shutoff and filters on all my small engines so I can run them dry when storing them. Storing them without fuel in the carb seems to minimize the pain come springtime.

One other thing is the low oil shutoff switch and fuel shutoff solenoid on the carb can give you fits too.

Didnt notice low oil shutoff as on my Honda generator. I just looked at vid on net he has identical carb. He rebuilt, I did exactly the same. I'm going to back off for a day or 2 and let my senses digest the problem. Something I'm missing. Thanks all.