I have a model 10515 that has become hard to get started. I changed the plug and cleaned the carb. If I prime it with WD-40 I can get it started and it runs pretty good. When I let it sit I choke it and it will pop and try put can't get enough fuel seems like. I have drained tank and replaced the line and the choke mechanism is closing fine. It has stopped while cutting and I can't get it started without priming but usually stays running as long as I want so I don't think the coil is the problem. It has the metal walbro carb. Gotta be something simple just kinda new to Lawnboys and aggravating to have so much starting trouble with something so simple.....or maybe not. Any advice appreciated.
22R
#2
BlazNT
Dirty carb, air filter or fuel filter. Compressed air for the little holes in the carb. Im betting carb.
#3
22R
Thank you for the reply. air filter is new, fuel screen filter is clean and I took carb apart and blew carb cleaner and then compressed air thru each passage. What boggles my mind is that it runs well once I prime it but it just won't draw enough gas on choke to get it going. I guess I missed something but I have an extra carb so maybe I will clean and try it.
You need to replace the top and bottom crank seals. Leaking seals let in air on the suction side of the piston compression stroke. This leans out the fuel air mixture.
#5
BlazNT
Not saying the seals don't need to be changed but the rest of that is not true. Rings keep stuff from the crank case out of the combustion chamber.
Air that is sucked by leaking seals into the crankcase leans out the fuel air mixture in the crankcase. This lean mixture is then routed through the transfer port to the top side of the piston to be burned in the combustion chamber. The rings have nothing to do with the path the fuel air mixture travels through the carb past the reeds to the crankcase through the transfer port to the combustion chamber on the top side of the piston to be burned.
You need to replace the top and bottom crank seals. Leaking seals let in air on the suction side of the piston compression stroke. This leans out the fuel air mixture.
I think that we may have a winner. upon further inspection I found the bottom seal down around the shaft away from the bearing where it should be. I have ordered two new ones. After I remove the flywheel do I have to take apart the housing to get the top one out or can I just pop it out in place to change it ? The bottom one being out I suppose that I can just caress the new one back in ??
Hopefully this will get me straight. Appreciate all the replies gentlemen.
There are videos online Youtube, that show you how to remove the seals with a screw and an electric screwdriver. Works like a charm. You pop them back in using a pipe, or deep socket that you can press on the seal and tap with a hammer lightly to get them seated.
The Lawnboy carb is a very simple device, on late models, there are really no adjustments for fuel mixture, and they are jetted lean, so any obstruction, or leaky gaskets between carb and engine block can lean the mixture out even more, to the point you have poor or no running. You have to actually remove the main jet (under the screen in middle of carb float bowl), and clean it separately to really get it clean. This is a long brass tube and there are several tiny holes in it, that can get closed up due to old gas turning to varnish, and just blowing thru from the bottom with air or carb cleaner will not truly get this clean. The main jet just unscrews, just like the needle seat does, by using a screwdriver in slots on bottom.
