# Gas running into crankcase



## Caper50 (Jan 7, 2017)

Hello, I have a Simplicity P1728E snowblower. It's 4 years old with a 342cc Briggs and Stratton engine. Problem is the gas is running into the crankcase. I took the carb apart and everything appears clean. I figure it's a problem of gas getting by the little valve attached to the plastic float. I expected to see a little rubber seal in addition to that valve but there was none there. Is this supposed to seal up against the hole on the plastic once gas fills the bowl and the float rises? I tried to find a diagram showing the breakdown of the carb parts for my machine but can't seem to find one to see if my carb is supposed to have that extra seal. Any help is greatly appreciated.


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## Mike C. (Jan 28, 2016)

Your assumption as to the cause of the problem is more than likely correct.

Please post the entire model,type and code numbers for your engine.Nobody can help you if they don't know what your working on.


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## Caper50 (Jan 7, 2017)

My manual says engine model 210000 machine model # is 1695990


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## Mike C. (Jan 28, 2016)

We need the numbers on the engine.There should be a model number,type number,code number.


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## Caper50 (Jan 7, 2017)

Mike, here is the info off the tag:
Simplicity P1728E, Model# 1695990
Engine Family: Briggs & Stratton BBSXS.3422SW BBSXPNHEQPH1, 342cc
Model 21M314
Type 0127F1
Code 111012YD


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## Caper50 (Jan 7, 2017)

Ok I think I found the Parts manual. It looks as though the needle valve just seats into the hole in the plastic housing. Surely this can't be worn already, but it's the only thing that I can think of as a cause of this. Am I missing something else?


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## motorhead64 (Dec 15, 2013)

A small spec of dirt in the seat will prevent the valve from adequately sealing, allowing fuel to migrate into the crankcase. Always use your shutoff valve and run your machine dry and you can minimize this. A better alternative is clean the float chamber and seat. MH


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## Caper50 (Jan 7, 2017)

I removed the carb and picked up a can of carb cleaner and will give it a good cleaning. I also plan on adding one of those red inline filters between the tank and the carb. Strange that the manufacturer didn't have one from the start.


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## Mike C. (Jan 28, 2016)

Is the tip of the fuel inlet needle rubber?If it's sealing against plastic,I would think it would need to be-but who knows.
If it's rubber,it may be deteriorating from contact with ethanol-if your gas has ethanol.

Also,isn't there a small diameter o-ring under that plastic plate?That might be worth looking at.

I've never seen the inside of one of these carbs in person-it's too new.I work mostly on older stuff.Just throwing a few ideas out there.

Be careful with the carb cleaner around the rubber parts-it's not always a good combination.


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## Caper50 (Jan 7, 2017)

Something else comes to mind...could my problem have been caused by my gas cap? Are these machines supposed to have a vent cap system? After finding the correct model number for the engine 21M314-0127F1 I was able to find the complete Illustrated Parts List for Model Series 21M300 Type Numbers 0017 through 3475. I see there are 2 different carb kits: Part #'s 796137 and 696146. Looks like the difference in the two are the float bowl gaskets. Mine appears to be 796137. This should help me in the future. Btw, I'll be using the fuel shut off valve after each use and for long term storage from here on in. Hoping a spec of dirt was in fact the real problem but worse case scenario the rebuild kit should solve the issue.


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## Caper50 (Jan 7, 2017)

Well this thing is kicking my ass. Flooding, running very rough and when I try to increase throttle it bogs out and stalls. Wondering if a small part dropped out that I may be overlooking.


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## Caper50 (Jan 7, 2017)

Well as it turns out a small part did drop out...it was the main jet. Thankfully I found it on the floor. Lesson for the day is make sure you take something apart in a parts basin or something similar. Bought a new carb kit from the dealer, only thing I changed was the gaskets, O-rings and needle valve. Running much better now.


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## motorhead64 (Dec 15, 2013)

Glad to hear you are up and running Good luck with it during the snow season. MH


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