# Tecumseh Vector Carbs- Starving for Fuel



## Tamfan (Jun 20, 2010)

Hi Folks,

Just wondering if anyone else is having similar problems to mine when it comes to the Tecumseh Vector Carbs.

I worked on a YardMachines Rider with a 13.5 HP Tecumseh. 
Engine was acting like it was starving for fuel. Replaced all new fuel lines, filter, and put on new Vector Bowl kit (Plastic Bowl assembly-basically the entire lower half of carb + new diaphram).

Unit ran fine as long as it was on level ground, but started to struggle under a load going uphill. 
Eventually it would surge and sputter and die. Some attempts to restart worked, but eventually it failed to restart.
Had some luck spraying starter fluid in carb, but after it quickly burned off--No luck.
Checked Choke plate function and plate opens and closes properly.
Throttle and linkages are not binding and work properly as well.

Checked fuel line to ensure gravity flow wasn't hindered, steady flow all the way to carb. Pulled bowl off carb and hardly any gas was in the bowl.
I would expect the bowl to be somewhat full if I have a good fuel stream coming from the fuel line to the carb.

Almost seems like the needle sticks in the seat, restricting incoming fuel. (just my guess)

Just wondering why after installing new Bowl Kit why these symptoms occur. These Vectors seem to fail alot. 

This unit used part #770639.(Carb Bowl Kit)

Engine is a Tecumseh OHV135-206904E


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## jsouth (Jan 31, 2008)

Try loosing your fuel cap,cap may not be venting causing a vacuum,and very little fuel flow.Hope this helps.

Jerry


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## John Lolli (Nov 3, 2005)

The Vector engine used two different carbs Split and Married. The only way I can tell the difference is to remove the drain bowl screw. On the Married variety there is also a spring, main fuel jet, and o ring. The o ring over time flattens out and blocks the main jet. If you have a Married carb then try replacing the o ring. I have seen this on a few Vector engines that run poorly adn the o ring solved the problem.


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## Tamfan (Jun 20, 2010)

Thanks JS and JL.

I tried loosing the gas cap while I was on the service call (forgot to mention that), it had no effect.

I'll check the O-ring. This is a "Brand New" Bowl kit w/ a new diaphram. Unless it was defective, the total run time after install was less than 1 hour before the failure started.
It would be hard to believe the O-ring failed so quickly.


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## 30yearTech (Sep 14, 2006)

Is there an inline fuel filter? If so is it one specific to a gravity feed system. The wrong kind of fuel filter will sometimes cause fuel starvation.


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## Tamfan (Jun 20, 2010)

30yearTech said:


> Is there an inline fuel filter? If so is it one specific to a gravity feed system. The wrong kind of fuel filter will sometimes cause fuel starvation.


Thanks 30Year, I'm going to try it with another filter. 
Hope it makes a difference. I matched it to what was on it on the service call, which was the common small red filters that are on a ton of small riders with Tecumseh and Briggs. Some of them are red, some are white, like Briggs #394358.


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## Tamfan (Jun 20, 2010)

*Vector Still acting up*

Customer wanted a new carb.

Installed a new Vector carb on this unit and they had it for 3 weeks and are now reporting the same problem is occurring again--- spits, sputters and stalls on an incline.

Anyone got any ideas?


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## geogrubb (Jul 28, 2006)

Not trying to be real scientific or technical, however, on this incline, if the engine is gravity fed and in one direction of the incline the tank is below the carb, no fuel flows and depending upon the relationship of the carb float to the incline in the other direction the float will not drop far enough to let fuel in as it thinks the bowl is full. It may be as simple as they started mowing in a different direction. Newton and I ate from the same apple tree. Have a good one. Geo


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## Tamfan (Jun 20, 2010)

geogrubb said:


> Not trying to be real scientific or technical, however, on this incline, if the engine is gravity fed and in one direction of the incline the tank is below the carb, no fuel flows and depending upon the relationship of the carb float to the incline in the other direction the float will not drop far enough to let fuel in as it thinks the bowl is full. It may be as simple as they started mowing in a different direction. Newton and I ate from the same apple tree. Have a good one. Geo


Thanks Geo, I considered that as well.

Here's where I'm at on this machine:

I put on a new fuel line without a filter (just to rule out a filter problem). 
Once I conquer this machine, I'll re-install a filter again.

I checked the O-ring in the jet, it wasn't flattened out, but I replaced it anyway to rule it out. 

I can get the engine to run on level ground for 2-3 minutes and then it sputters out and dies.

Once I move throttle to Full Choke, I can restart it with no problem.
It does get finicky when restarting and it will stay running as long as I play with the throttle cable, engaging the choke back and forth. 
It still seems to "want" to run rich.

BUT....
if I spray starter fluid in the throat, Fully choke it, it will start. Then I can back off the choke to open the choke plate wide open, and it will run 2-3 mins and die again.

Now about the Fuel Tank Cap:
I ran all the above mentioned test with the fuel cap off.
I should know this, but I'll ask anyway,... is this an acceptable way to rule out a clogged fuel cap? 

I'm still stumped, but determined to get it solved.

Thanks Guys!


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## John Lolli (Nov 3, 2005)

Have you solved this problem yet ???


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## Tamfan (Jun 20, 2010)

John Lolli said:


> Have you solved this problem yet ???


John,

I tried replacing the O-ring on the new carb and still had the same problem.
I went back and took the original carb and replaced the O-ring for the second time and it performed well with no hic-ups.

Thanks for your advice!


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## John Lolli (Nov 3, 2005)

One thing I have learned regarding these vector carbs is that you have to really push down on the red plastic jet when you seat it. I has to sit just a little below the thick gasket that is between the upper and lower halves. Sounds like you got it squared away -- thanks for the response.


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