2 Tecumsehs Same Motor, Same Problem

[Maritime Storm]

My spring ritual has occured over the weekend, drop into my father's, sister, & father-in-laws dig their mowers out get em ready for the season. Did 2 of the 3 yesterday, the third is today's project. I introduced all three of them to fuel stabilizer last year in order to make my life easier in the spring, apparently not soon enough. My father's & sister's mowers are identical l-head 148cc 3.8 hp Tecumseh engine MTD 22" lawnmower. Both have primer carbs, both of them the primer is gummed up after sitting over the winter. After a bit of coaxing I got both to start. I always put 30ml of Carb cleaner & Marvel Mystery oil in the tank of each mower in the spring to help clean out any [censored] that has developed. Do I have to go through the trouble of pulling the carbs & disassembling them or is their a chance that they will clean themselves out after a bit of running?

 

[Pablo]

A few questions. What kind of fuel stabilizer? Was it run through?

The carbs may clean themselves. Sometimes I find adding a good synthetic 2 stroke fuel mix in gummed up systems yields very surprising cleaning results.

 

[1sttruck]

I never used a fuel stabilizer, and never had problems with a Murray motor that had a Tecumseh engine. We bought it used from a friend about 15 years ago. One year I tried some Seafoam, carb cleaner and such to see if it would make anything better, it didn't, so I just stuck to changing oil and spraying the while mower down with WD40. We finally gave it to someone after someone gave us a newer mower, and they're still using it.

 

[shoz123]

If the carb is like that on my snowblower with a Tecumsehs OHV motor has about three or four very small ports/passages in it. They are so small they are hard to see. These will easily clog up and you need some very fine wire to clean them out.

 

[Lost1]

I've found both Tecumseh & B&S engines to be temperamental if fuel stabilizer isn't used before winter storage, with Tecumseh's being the worst. When they sit outside in the elements it's worse as condensation will build up in the float bowl & gas tank, making starting impossible. The internal carb parts will also tend to corrode, but can often be salvaged by simple cleaning.
You can usually drain the gas tank, then drop the float bowl & clean it out along with the float & float needle, then spray out the little passages with carb cleaner- all without pulling the carb off the machine. This will usually get the machine running, after which a little fuel stabilizer and a covered storage area will go a long way in preventing it from happening again.

I use Sta-Bil fuel stabilizer year round in all my OPE- it keeps the fuel systems clean and as long as I keep the equipment in my shed I never have starting problems regardless of how long the engine sits.

 

[paulo57509]

There might be some self-cleaning action that takes place, but the crud that gets cleaned off is the stuff that causes the problems. I would think that using Sta-Bil would help during long term storage after you get the carbs cleaned up.

I use Sta-Bil year-round and prior to putting the mower away for the "winter" (this sounds WEIRD as I live in CA) I close the fuel valve and run the carb dry. This might be a problem in a more humid environment, but it doesn't seem to be a problem for me.

I don't have any such ritual for the string trimmer or the blower, though. Craftsman states that their 2-cycle oil has stabilizer in it, so I don't bother with mixing in additional fuel stabilizer.

Haven't had any start-up problems in the spring.

 

[Maritime Storm]

I'll try that. Number 3 was the real fun, blade worn flat, primer not working, carb varnished up to the point that it almost won't stay running at idle. The carb on it may end up having to come off. I'll start by dropping the bowl & trying to clean that way first. Thanks for the advice guys. Anything else that may help?

 

[Saturn_Fan]

Sta-Bil is great stuff. I store my boat outside year round with Sta-Bil in the tank (73 Johnson 25HP outboard) and every year it starts and runs on the 3rd pull. My Tecumseh Sno-King gets Sta-Bil year round as well and performs flawlessly. You gotta keep the fuel fresh in these small engines.

 

[Rolf]

Originally Posted By: Maritime Storm
Both have primer carbs, both of them the primer is gummed up after sitting over the winter. After a bit of coaxing I got both to start. I always put 30ml of Carb cleaner & Marvel Mystery oil in the tank of each mower in the spring to help clean out any [censored] that has developed. Do I have to go through the trouble of pulling the carbs & disassembling them or is their a chance that they will clean themselves out after a bit of running?


I have had a series of equipment, including mowers, with the Tecumseh 5-6.5HP vertical shaft engines with the 7/8 x 3 5/32 crank.

Every year before I put them in storage I give them a liberal dose of Chevron Techron Fuel System Cleaner, about 25% of the gas tank, for the last two tanks of gas.

It completely eliminated the problem you describe.

I'd dose then with the Techron - I think you'll find that the crud will dissolve after a tank or two.

 

[Cmarti]

Honestly, I have worked on hundreds of small engine carbs in my life, and I use Seafoam at 1 oz per gallon in all my fuel when I bring it home (to dry and stabilize). Regardless of this, i recommend buying a $4 fuel line shut off valve and running carbs dry. Then use the drain on the carb or drop the bowl. If you can't afford the valve, or can't get at the fuel line, waste the $1 of gas in the tank and run/dump it dry. Fog the tank if not plastic and leave the cap off.

I did have a great summer job in college working at my uncle's power equipment store.I cleaned float needles and seats and nozzles of gum every March, april and may when everyone went to start their equipment. Snowblowers were big in November, but I was gone. We would not have had the work if people would just get the gas out of them. Many claimed to use a stabilizer, but who knows if they did the right amount or ran it through the carb.

 

[browning300wsm]

i close the petcock under the fuel tank and let it run till it dies from lack of fuel ..ps. no fuel no gum ...

 

[Bill Kapaun]

Except from the little bit of gas that doesn't get burn out of the carb. You don't think the bowl empties completely do you?

To the OP-
IF the Tec's have the plastic bowl carb, there is a complete bowl kit available for $15-20.
It basically like installing a new carb.

 

[browning300wsm]

Originally Posted By: Bill Kapaun
Except from the little bit of gas that doesn't get burn out of the carb. You don't think the bowl empties completely do you?

To the OP-
IF the Tec's have the plastic bowl carb, there is a complete bowl kit available for $15-20.
It basically like installing a new carb.


yes BILL you r right !!!!!,the little gas left in the bowl drains out when i remove the mixture screw on the bottom of the carburator bowl ..

 

[Cmarti]

Originally Posted By: browning300wsm
Originally Posted By: Bill Kapaun
Except from the little bit of gas that doesn't get burn out of the carb. You don't think the bowl empties completely do you?

To the OP-
IF the Tec's have the plastic bowl carb, there is a complete bowl kit available for $15-20.
It basically like installing a new carb.


yes BILL you r right !!!!!,the little gas left in the bowl drains out when i remove the mixture screw on the bottom of the carburator bowl ..


Many Tecs have a spring operated drain screw. Just press it in. Be careful droping the bowls on some Walbro carbed Tecs, as the bowl has to go on a specific way for the float to work(Sno King snow blower engines). Hondas have a screw in drain, and most Many briggs use Nikki and Walbro that you can just drop the bowl with a retention bolt. Not all the gas gets out running it dry, but it is not sittting turning to goop in the pick up tube of the nozzle/jet. Also, if cleaning the carb try WD 40, easier than solvents on the o rings, gaskets and nylon tipped float needles.


You are right though, just get the gas out of it for storage, and save yourself 50$ at the hardware store next spring.

 

[Maritime Storm]

No plastic, all three are dual system Tecumseh carbs with metal float bowls on them. Attempt no 2 showed improvement, sprayed most of a can of carb cleaner(aerosol) inside the carb with the bowl removed & in the throat. But it still isn't running 100%. Will continue to fight with it.