stevek433

HI Group:

I now have have TWO Simplicity Sunstars with the Kohler Magnum 18 engines sitting in the garage. Both came from the same person and were used for snow removal here in CO. Both in rough shape but hey, I paid 200.00 for both.. with a nice 42" snow plow.

So, starting with the "better" one, I did a complete tuneup -- new battery, plugs, new oil, new fuel line, new fuel filter in the gas tank, changed the transimission fluid, pulled and de-carboned the heads and replaced with new head gaskets, checked the piston/bore, checked the valves-- all within spec. New tubes in the tires, new bushing in the axles. Hey this is FUN!! Maybe for once in my life my "cheapness" scored big.

Of course, I rebuilt the carb. Soaked the carb overnight, blew it out, put in the new carb kit and viola -- the sucker started!!!! I had a BEAUTIFUL running tractor. Sounded just great. Good for me-- I restored my first Sunstar!!

10 minutes of driving it around the house, putt putt putt and gas begins spewing out of the carb. Great. Just great. What did I do? Tore the carb apart again, looked at the needle, rechecked that the float was parallel... sprayed everthhing with carb cleaner... it all looked good to me. Put the carb back together, started the Sunstar and the gas was just spitting out of the carb. Even worse than before. My wife was laughing at me.. not funny.

Obviously I am not missing something. Is it the needle not seating? Any ideas?

Thanks Steve

HYDROGUARDIAN16

If the float is made of brass , they are notorious for leaking and sinking to the bottom of the bowl. That is one thing I know that has happened to me before

__________________
2003 Simplicity Regent 18HP Vtwin
-
1986 Bolens 1800 / 5018H
-46" 2 stage snow thrower
-
1966 Wheel Horse 606
-
Gravely 3 Wheel Triplex mower
-
70's Jacobsen 1000 chief

dangeroustoys56

Did you check the float needle seat( its made of rubber) ? If that didnt come in the rebuild kit- you might need to get one. That or somethings is sticking- usually if extra gas goes in, itll use it- when its shut down, it can fill the combustion chamber and seep past the rings into the oil ( id check that too) - if gas dilutes the oil it can blow the motor up.

Probably wouldnt hurt to add a fuel shutoff valve either.

stevek433

HI Group

Well progress. Today, after doing some more research, I found that spitting gas out of the carb usually means a intake valve sticking open -- and NOT a carb issue. Not to say the carb is/was working perfectly, but this is a deeper problem than just the carb.

Sure enough I pulled the heads and the intake valve on the No 2 cylinder was stuck partially open. I jimmied the valve with a screwdriver and was able to get the valve to "release", i.e. jimmied the valve stem which allowed the valve spring to retract and seat the valve as I rotated the crank with a wrench. Net I got the intake valve "working" again.

Just to see if the tractor would run, I put the head back on (used original gasket) and sure enough the tractor started. Ran rough, but started and NO leaking gas from the carb. So success on the leaking gas.

Now I need to really recheck the carb for any tiny holes that are blocked to see if that is why the engine runs rough. I do want to do a cylinder leakdown test to determine if the valves are truly sealing. The valves looked pretty good for a 20+ year old engine, but one never knows. After this test I can see if I need a new head gasket or a valve job.

I will change the oil this week just to be safe, and re the float... it is plastic and no leaks. Net progress today but still not quite there.

Steve

dangeroustoys56

I never wouldve thought of that - ive had some carbs doing the exact same thing- id clean the carb and problem was solved. Ive never had a sticky valve either - not even the ones with the upper intakes full of rusty water.

Usually when i drag my non running hulks home, i spray the heck out of the combustion chamber with PB blaster and let it soak in for a while ( itll burn when it fires up) - that way stuff will free up a bit and gives a lil bit of pre lubrication as well.