2082 boiling fuel in carburator?

Valleyvfdfirefighter · #1 05-14-2018, 05:05 PM

Hey guys I'm having a very sudden issue with my cub cadet 2082.

It has had a Magnum 18 engine installed into it about 6 years ago from the PO.

My issue just started last week and I'm a bit lost. I can mow with it for about 15-20 min and then it will start to die. Only way to sometimes keep it running to limp back to the garage is to pull the choke out all the way. Still then it just diesels, blows some black smoke and mostly dies.

I'm getting good spark on both cylinders during this as I've checked it with my in-line spark tester. I initially thought it to be a faulty pulse fuel pump as it seemed to be starving for fuel. However, its definitely getting furl.

What I did notice today when I pulled off my air filter was a bit of fuel in the carb under the air filter and a crackle pop noise coming from the carb.

Put a stethoscope to the bowl and it sounds like the fuel is boiling like crazy giving me a vapor lock. I pulled the carb and pulled the bowl to find a lot of rust in the bowl. Cleaned the bowl out, pulled the high idle needle and cleaned everything the best I could. Reassembled it and yet again after a few min it goes from running WOT to dying.

Thought maybe the carb needed adjusted. Closed all the adjustment screws and backed them back out 1-3/8 turn as per the cub cadet manual. I can turn the adjustment screws for both high and idle in and out and barely get any engine rpm change. I'm meaning I can turn the screws in and out 4-5 turns and engine doesnt seem to change.

Intake manifold right after the carb is cold and sweating but I'm still getting boiling sounds and an occasional white smoke coming from the carb.

Any suggestions?

R Bedell · #2 05-14-2018, 05:47 PM

I can think of two issues. (A) It is time to pull the engine, then pull the Engine Air Duct shrouds off exposing the back or flywheel portion of the engine. I am guessing it needs a massive cleaning. (B) Pull the carb, take it aparts, and do a thorough cleaning.

Once the engine is clean and moving the correct amount of air, along with a clean and properly adjusted Carb, I going to say, it will run better.

Valleyvfdfirefighter · #3 05-14-2018, 06:37 PM

R Bedel,

The engine is free and flowing massive amounts of air. I'm very big on blowing it out after each use. I actually took all the tin off the other day thinking it must be getting to hot. However, IR reads about 220°-335° around the whole engine.

I finally got it to run but I have the left tin off and the hood and left plastic off. I dont know if it will start boiling again if I put everything back on. I had to get my yard done!

R Bedell · #4 05-14-2018, 06:43 PM

The "heat" is coming from somewhere.

CubDieselFan · #5 05-14-2018, 07:10 PM

If you keep overheating it, you will kill it.

Alvy · #6 05-14-2018, 07:15 PM

You may be blowing it out as best you can after each use but if there’s any sort of oil leak from the crank seal even the smallest seepage it will gunk up all the fins where you can’t get to or see. It is an older Magnum after all. I would do as suggested to be on the safe side.

john hall · #7 05-14-2018, 10:26 PM

Kind of with Alvy on this one, better take a look and see if its insulated with grease and grass clippings. Just wondering if its running too lean, timing off (don't know how that could happen), or any kind of heat shield is missing. You say its sudden, maybe its the last fuel you bought. How about draining the tank and getting a gallon of freshly purchased fuel--myself, I'd get name brand not Bubbas quickie mart.

zippy1 · #8 05-14-2018, 10:46 PM

Going with Roland, Mike and John on this one.

So now you have four members with the same suggestions to your question. What you gonna do?

jerkin · #9 05-15-2018, 07:46 AM

Did you check the spark while it was hot or after it had cooled down? Coil going out will sometimes work when it's cold then quit after it heats up. Maybe it is the unburned fuel you are hearing and causing the occasional white smoke? Smell any gas in your oil? That would be a sure sign. Just something else to check but I'd probably still yank the engine and clean it, just did it to my 1864, not a bad job at all.

Valleyvfdfirefighter · #10 05-19-2018, 06:36 PM

The tins were taken off before I posted the question and the engine was squeaky clean. Obviously minus some dust. No oil leaks, no grass, no nests in the engine tins.

I couldn't get the carb adjustments to do anything but remembering I put gas in it from a neighbor's gas can right before it acted up I opted to dump about a gallon of gas gas of the bottom of the tank. Used the pulse pump to pull it out. Filled the rest of the tank up with fresh gas and was able to get the carb mixture adjustments to finally work. Got it adjusted right and I've not had an issue with it yet with stalling.

However that being said it has been pouring down the rain since my original post so the grass is growing tall and thick. Tuesday may just be the test day!