boiling fuel problems

cubby102 · #1 08-31-2012, 12:08 PM

I just mowed with my 102 for the first time this season because of a belt problem I got that fixed but now I seem to be having a heat problem I know for a fact the shroud as well as the fins are clean and clear but it got so hot it started to blow some slight smoke out of the vent on the side and when I got done I was checking everything out. I pulled the gas cap and the fuel was boiling like it was on top of a stove. I only ran it about a hour or so at 3/4 to WOT in some areas . Also another thing that might or might not be related. I thought I had it licked but my starter solenoid is sticking to where the engine will keep cranking even after key is off and key switch is even unplugged . Any ideas would be great. Sorry for the book but I'm kinda lost

jim102 · #2 08-31-2012, 12:43 PM

i dont know about the starter issue but i had a similar condition when my carb was dirty and engine was running lean. my muffler was nearly glowing. i removed carb, cleaned it thoroughly and reinstalled, adjusted it and no more issues. hope yours is as simple.

CADplans · #3 08-31-2012, 02:22 PM

Quote:

Originally Posted by cubby102

I thought I had it licked but my starter solinoid is sticking to where the engine will keep cranking even after key is off and key switch is even unplugged . Any ideas would be great. Sorry for the book but I'm kinda lost

The points in the voltage regulator are "welding" together!! I had a "148" that would do that, I tapped the regulator to get the starter to stop turning the engine!!

I finally replaced the regulator.

cubby102 · #4 08-31-2012, 09:11 PM

Quote:

Originally Posted by CADplans

The points in the voltage regulator are "welding" together!! I had a "148" that would do that, I tapped the regulator to get the starter to stop turning the engine!!

I finally replaced the regulator.

ill have to check that out i have a few spare regulators floating around i never even though of that. it only seems to do it on longer runs when she really gets worked. thanks for the idea ill check it out in the am

cubby102 · #5 08-31-2012, 09:12 PM

Quote:

Originally Posted by jim102

i dont know about the starter issue but i had a similar condition when my carb was dirty and engine was running lean. my muffler was nearly glowing. i removed carb, cleaned it thoroughly and reinstalled, adjusted it and no more issues. hope yours is as simple.

ill go through it again maybe i just have it set to lean. it was just rebuilt about 4 months ago along with new sediment bowl and line. wouldnt hurt to go through it again just to see. thanks

darkminion_17 · #6 08-31-2012, 10:52 PM

I would also check your points. The motor will run hotter if it is not set to the correct gap especially if it is set less than. 010.

save_old_iron · #7 09-01-2012, 04:19 AM

One quick check would be to confirm the Cutout Relay contacts in the VR are not "welded" together from pitting. If they stick together, current can go backward from the battery to the starter generator EVEN WITH THE KEY IN THE OFF POSITION.

Open the VR

Locate the Cutout relay. The wire windings on the Cutout relay will be a much larger diameter than the volt / current relay

Press down on the relay contact arm (marked with the "X") and observe the contacts - they should open up completely - probably around matchbook cover thickness.

If the contacts fail to open or "pop" open, there may be significant pitting bridging the gap.

Cleaning the relay contacts with a points file can temporarily restore proper operation to the VR.
400 grit wet / dry paper on the contacts can also be used as a temporary fix.

save_old_iron · #8 09-01-2012, 04:32 AM

The "boiling gas" is interesting. Different blends of gasoline will "boil" at temperatures from 100 F to near 500F.
If you did not burn your fingers on the metal cap of tank then I assume the temperature of the tank was less then 150 F.

Is it possible you are at a high altitude or have a winter blended gasoline pumped earlier this year in the winter / spring time frame ?
Winter blends would vaporize / boil at lower temperatures.

R Bedell · #9 09-01-2012, 06:15 AM

Quote:

I only ran it about a hour or so at 3/4 to WOT

Being a HVAC/R Tech, to get the maximum amount of engine cooling, the motor needs to be run at WOT (or 3600 RPM). This is also recommended in both the Cub Cadet and Kohler manuals.

PaulS · #10 09-01-2012, 07:04 AM

All good info here. One more point is to keep all shields and tins around the engine. These direct air from the cooling fan around the cylinders mostly from back to front to keep things cool. One more point, inspect the shroud area where the engine fan is to be sure critters have not built a nest in there obstructing air flow and after mowing I blow air between the tins to get rid of detritis that tends to build up there. Once per year at least I remove the shields around the cylinders and thoroughly clean the fins around the cylinders.