My MTD 115/76 with a Tecumseh Formula 12.5HP Engine was working ok but then will no longer start. I have changed the inline fuel filter & fuel ssems to be getting to the carburettor ok, but there is no sign of wetting on the spark plug. Reading comments there seems to be an issue with this type of carburettor involving a solenoid. I cannot seem to find any specific information on these carburettors. Should I look to replace it or is there a better alternative to fit? Any help would be much appreciated. Terry

Did the machine sit for awhile  (months) , with fuel in it?
 
Also, a model # for the engine itself would help us.
 
The carb very likely just needs a good cleaning BOTH outside and especially 
inside.  
 
A carb clogged and varnished up:

 
After cleaning:
   
 
Pulling your carb apart will likely look like this:

 
It has to come off the machine and disassembled.  All internal jets and orifices must be clean and open.
 
 

Hi, thanks for the reply. No the machine hadn't been sitting & when I removed the float chamber it seemed to be clean. I wondered if the problem lies with this particular type of carburettor. I have attached a picture of the Tecumseh model label. Thanks, Terry

Here is the picture.

Pic is too small for me to make out the model #...
 
Did you pull out the main jet to make sure it was clear?
Squirt carb or brake cleaner thru all the orifices (and have it come out somewhere)?
 
**Did you try removing the air cleaner and spraying some starting fluid down the carb just before starting?
If it's a fueling issue, it light off momentarily.
 
You also mentioned solenoid earlier. You pic doesn't show a shut off solenoid attached to the bottom of the fuel bowl, or am I just missing it?    The solenoids do have a habit of clogging the fuel flow, but I don't think you have one..
 
.
 
.

Hi, I posted before on the problem I am having with my MTD 115/76 Ride on Mower. It has a 12.5HP tecumseh engine (model number shown in the picture. I thought at first the problem may have been the fuel, so replaced the inline fuel filter, carburettor etc., But it appears the problem is electrical. I couldn't get any sign of a spark, so replaced the coil & spark plug but still no joy. Even removing the kill switch wire doesn't make any difference. Any help on troubleshooting would be much appreciated. Thanks, Terry

Model # is OV358EA   
 
https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/tecumseh/4-cycle-vertical/ov358ea/ov358ea-206940g/engine-parts-list-1
 
Did you use the OEM coil, part # 100?
https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/tecumseh/4-cycle-vertical/ov358ea/ov358ea-206940g/engine-parts-list-1 
 
Also did you try another known to be good spark plug well grounded to the block?
 
 
.
 
 
 
 

Many thanks. I will try again today. Regards, Terry