# Mantis tiller no start



## 84HyperZ (Jul 28, 2010)

Working on a mantis tiller for my aunt's friend. Would idle but bogged and died under throttle. Was informed that they had messed with jets a bit and upon removal of the carb and primer found stale gas in the carb. Replaced carb for new rather than rebuild and fight the jets and now won't start at all. Getting spark. Cleaned the magneto and armature with carb cleaner and fine grit sand paper. Haven't yet checked the compression. Any thing i'm missing?

thx 
Chris


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## jsouth (Jan 31, 2008)

check compression,should be a least 90# or better to run.Also check the spark arrester screen in the muffler,could be clogged.Hope this helps.

Jerry


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## nnyparts.com (Dec 28, 2009)

Jerry is right on about the compression...to low and it won't start and run. Another thing to look at and I can't stress it enough is what part ethanol is playing with small engines. If no additive is used, ethanol will separate and tend to lay at the bottom of the tank. Most of the small engine equipment out there draws from the bottom of the tank...so you end up getting straight ethanol through the engine. There are many additives out there and I would look for one that does both...fuel stabilizer and ethanol treatment.


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## 84HyperZ (Jul 28, 2010)

thanks guys i will check into the both and post back with the results. :thumbsup:


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## 84HyperZ (Jul 28, 2010)

checked compression by pull: 45, 70, 90, 120, 135
spark arrester screen was somewhat clogged, soaked in cleaner for a bit then replaced.... still no start

also the additional info on the tiller its a Mantis 21.2cc
engine family# TEH021UB24RB
the carburetor that replace the original is a Zama C1U KS4A


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## 30yearTech (Sep 14, 2006)

nnyparts.com said:


> If no additive is used, ethanol will separate and tend to lay at the bottom of the tank. Most of the small engine equipment out there draws from the bottom of the tank...so you end up getting straight ethanol through the engine. There are many additives out there and I would look for one that does both...fuel stabilizer and ethanol treatment.


Phase separation can occur with ethanol laced fuels, but it's not the ethanol that separates out from the fuel. Alcohol has a natural affinity for water, and can draw water out of the atmosphere like a sponge. That's how water ends up in a lot of fuel tanks and containers in high humidity areas. In a 2 cycle engine where oil is mixed in the fuel any water that ends up in the tank can separate out and settle to the bottom (since water is heavier then gas and oil). Alcohol will mix with water and can burn this way, and since there is no oil present in the mixture, it can cause damage to a 2 cycle engine.

*As for the Mantis tiller, I would suggest trying to start it with a prime to see if it will at least start. You have plenty of compression base on your post, so this will tell you if the problem still lies in the carburetor or if there is something else that may need to be checked.*


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## LowRider (Dec 23, 2008)

disconnect the on off switch. have had a few go bad.


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## Lawnmowertech (Nov 12, 2008)

84HyperZ said:


> checked compression by pull: 45, 70, 90, 120, 135
> spark arrester screen was somewhat clogged, soaked in cleaner for a bit then replaced.... still no start
> 
> also the additional info on the tiller its a Mantis 21.2cc
> ...


How is the spark on this unit will it show blue spark or is it orange ?


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