10201 , #39089612 cycle, hard to start hot, then runs rough

[Jim S]

Hi all,

My problem, 10201 , #3908961 2 cycle, It is hard to start hot if it has been sitting more than 5 minutes. If I can get it going it runs rough from 1 to 3 minutes before it settles down. Been thru the carb numerous times, carb is tight and gaskets good. Just pulled off fly wheel to check seal. Sprayed top of it full of wd 40 two hours ago, and its still all there. I haven't checked the bottom seal. Where should I be looking, if not at seals?

EDIT: I replaced the coil last week, has spark when hot. When it acts up, adjusting mixture has no effect at all.

I don't have to shut it down while mowing the yard, but it's just bothering the heck out of me, cause it isn't right.

Thanks,

Jim

 

[Jim S]

Come on guys, I need some ideas, please.

Thanks,

Jim:smile:

 

[Fish]

Even new, one could only say that the carb was "Junk". But back when I worked at a Lawnboy dealer, if you ordered a new carb,
they gave you a box of plastic carb parts, new.....

 

[Jim S]

Hi again,

I'm feeling carb issue of some sort, it only has one needle for low speed. I get that dialed in at 24-28-00 rpm, per spec at 3/4 to 5/8 out, but it 4 cycles at max governed speed. appx 3050 +/-100. .Have to close it down to 1/2. Now I'm thinking about it, I saw on You-Tube, cw rotation of the governor collar increases speed, and ccw decreases speed. Anyone experienced on a Walbro LMR-16 carb? Must be some transition from idle to high and I just don't have it fingered out. :roll:
Any way seal on top looks good, should I check the bottom one?

Thanks,

Jim

 

[turfboy1997]

I think both seals need it. I believe the v series uses the same seal as an f series. I would check behind both welch plugs and clean till you can see light through the orifices and pressed in main jet. I have been using simple green on these walbro carbs with great success. Just don't leave them in the dip too long because it will discolor the aluminum. Only maybe 1-3 hours. I have also had bowls that were ate up so bad that the had some corrosion through the bottom that made them leak and run poorly. This is and awesome carburetor but it has it's advantages and dis advantages. It had to be super clean and have no air leaks or you will never get It dialed in. Sometimes the governor spring needs replaced and can cause it to run weird. Also replace your fuel line. Sometimes you can be sucking air through the fuel line and not know it because of micro size cracks. Other than that I go to compression issues. Good luck and I hope this helps.

 

[Jim S]

Thanks Turfboy,

Fuel line is new, as is gov spring, welch plugs sealed again every time I take carb off just to make sure. On this LMR-16 what direction do you turn the governor collar to increase and decrease speed? I've been turning cw to speed up and ccw to slow it down.

Sometimes it just gets a mind of its own, and maybe because I just went too far one way or the other.

Tried finding seals locally, no joy. Looks like e-bay will be my friend again. But I've got a nagging feeling this is a carb issue and I just don't have it set right.

Thanks again,

Jim

 

[LB8210]

Seals can be bad and show no sign of fluid leakage but the also have to hold against leaking air on the suction stroke of the piston. If they leak air the fuel air mixture is diluted to being too lean a mixture to run. Replace both seals now.

 

[turfboy1997]

Seals can be bad and show no sign of fluid leakage but the also have to hold against leaking air on the suction stroke of the piston. If they leak air the fuel air mixture is diluted to being too lean a mixture to run. Replace both seals now.

I'm with you on replacing the seals. That is a very reliable carburetor and i doubt that is the problem. yes clockwise speeds up approx 50 rpms per click and counter slows approx 50 rpms per click.

 

[Jim S]

Thanks guys,

Seals it will be. Looks like E-bay is gonna be my friend here. Would like to get local as I have a long weekend, but so far, no joy.

Happy 4th to all.

Jim

 

[Phototone]

Thanks Turfboy,

Fuel line is new, as is gov spring, welch plugs sealed again every time I take carb off just to make sure. On this LMR-16 what direction do you turn the governor collar to increase and decrease speed? I've been turning cw to speed up and ccw to slow it down.

Sometimes it just gets a mind of its own, and maybe because I just went too far one way or the other.

Tried finding seals locally, no joy. Looks like e-bay will be my friend again. But I've got a nagging feeling this is a carb issue and I just don't have it set right.

Thanks again,

Jim

Generic LawnBoy seals are under $2 each at Tulsa Engine Warehouse. Will fit all Lawnboy 2-cycle mowers. They have an internet site. Not affilliated.