kohler magnum 20 , major flooding .. help..

patp744 · May 18, 2014

ok .. first weekend with my new to me terramite t5c..

i have no history so i decided to do as much maintenance as i could .. hydro, oil and filter, fuel lines , filter , shut off .. oil change , plugs ..

there was fuel leaking from the bowl, so i took the carb off, cleaned it out , resealed it , tuned it ..
i had it running pretty good ..

went to the shop to play with it today ..nope..

it would not turn over this morning after checking a few other things i took the plugs out, turned it over and shot fuel 12 feet high !!!!!
drained all the oil and fuel from the crank case .. took the carb off again , the float seems fine , sprayed out all the ports .. put it back together ..

hooked up the fuel lines , by time i got the linkage done the carb was full of fuel again.. i hurried and pinched off the fuel line and called it a day ..

i don't think its a float problem , the float moves fine .. i think i may of lost the little solenoid gasket that pin drops on to .. but not sure..

partstree seemed to be the only ones that had a listing for the parts.. not holding my breath ...

so... any help tracking down parts or what i could use as a new carb would help very much

the carb is a WALBRO adjustable main jet .. not sure which #'s are the model #...... i ordered # 21 and 16 on the parts photo .. hopping to at least get # 16 .. but doubt it ..

kohler magnum 20 khp 49629 ... m20s

J_J · May 18, 2014

Check your needle valve and seat for debris or corrosion.

The float might move up and down, but if the needle valve is not sealing, it will leak and fill the crankcase.

I would go ahead and install a fuel shut off valve.

Spanky100 · May 18, 2014

J_J said:
Check your needle valve and seat for debris or corrosion.

The float might move up and down, but if the needle valve is not sealing, it will leak and fill the crankcase.

I would go ahead and install a fuel shut off valve.

I would second the infomation JJ posted including installing a fuel shutoff switch. I have a Kohler Magnum 18 on a Cub Cadet that was purchased new by my Grandfather. After over 25 years of service it would not start after leaving it set overnight or longer. It would not start due to flooded condition. You can verify this condition if you have have a fuel line shutoff to turn the fuel off when you stop the engine. Carb looked the same as your pictures. Purchased a carb rebuild kit (IIRC about 10 USD). Included gaskets and the needle valve and seat. After replacing the needle valve and seat it is starting great again.

Good luck.

hawkeye08 · May 18, 2014

My Kohler has an electric gizmo on the carb that is supposed to stop backfiring or something... it went out and was expensive to replace. I put a shutoff in the fuel line and just turn off the fuel when not using it. It has worked fine for more than 5 years. Before I figured out what was wrong, I had gas in the crankcase a couple of times.. it was flooding when sitting and flowing into crankcase..

mrmikey · May 19, 2014

The Bolens I use in the woods has the same carb. First problem I had was the brass float was leaking and filling up with fuel and flooding the engineso I replaced that. Next problem was every couple of months or so I'd have to reset the float height. Apparently going over the bumps in the woods would eventually bend the tang on the float allowing the fuel to flood the engine leading to the same symptoms you have. If it's not the needle and seat like JJ said check out the float and height......Mike

patp744 · May 19, 2014

thank you for your help,

fuel shut off valve already installed ..

i also found a repair/rebuild kit at ope engines and a replacement float kit there.

there on order, i hope they have them ..
i found it supreisingly hard to track down parts for this carb ,
and very little info on it other then the needle settings in the kohler book ..

waiting for shipping notice

i guess in the mean time i can take the carb back off and take a closer look ..

is there any way to bench test this carb ?

mrmikey · May 19, 2014

is there any way to bench test this carb ?

I put a small hose on mine and blew lighty in it while turning the carb upside down to check the seat. Not what you'd call a professional assesment but it worked for me

.....mike