Pump Element on a Ted Williams 7.5TG

Steve M.

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Oct 21, 2008
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A friend of mine has a Sears model 217.58821 s/n 200751 made by Eska. 1971 I think. It has a Tecumseh power head & carb. I've worked on small engines (at Sears) for a number of years and still work out of the garage but have never had any experience with this type of 2-cycle carb. I'm in Illinois and he's near Detroit...trying to help LD.

What I'm curiouis about (and hope someone might shed some light on here since there seems to be YEARS of experience) is what the "pump element" is in the carb...it's function and/or purpose. In other words, does it function in the "normal operation" of the motor itself, when the external tank is in use, or both?

When he took the carb apart to clean it, this rubber element had a hole it it, so...thinking it just functioned with the external tank, he removed it and plugged the hole. We met up in Michigan last week, took out the boat, and it ran good, but wanted to cut out at full throttle. I adjusted the mixture and seemed to run a little better. I suspect the pump element and found one at Boston Lawnmower Co. out on the East coast. BUT...I'd still like to know what the heck it does!

"Enquiring minds"...ya know:confused:

Thanks in advance if anyone can help solve the riddle.

FYI: The part numbers shown on the Sears website for this unit are actually Tecumseh numbers.

Great forum.

Steve
 

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
28,555
Re: Pump Element on a Ted Williams 7.5TG

I had a 5HP Eska of about that vintage. The pump element looks like a small balloon. As the piston moves up and down it alternately provides suction to the pump element to expand it pulling gas from the tank, and then provides pressure to the element collapsing it and pushing the gas into the carb.

If that motor has an built in tank, you can probably plug the pump element hole and run on it.
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: Pump Element on a Ted Williams 7.5TG

Actually, not. All the carbs that use the fuel pump element also have a set of tiny flapper valves right behind the fuel inlet. They look like a little gasket behind the flat housing that is attached to the fuel inlet. Even with the internal tank, the engine won't run right without the element and flapper valve in place. Along with pumping fuel, it also makes those flapper valves open and close.

The pump element isn't expensive. Replace it and your outboard will run at its best, at least for a while. Bring your oars, though, or an electric trolling motor. One day, and you won't know when, you'll need another way to get back to the dock with those Eskas.

My advice for Eska-based outboard owners is to get them running well, shine them up, then sell them and buy a Evinrude or Johnson of similar horsepower. You'll be far happier.
 

Steve M.

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Oct 21, 2008
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Re: Pump Element on a Ted Williams 7.5TG

Sorry it took so long to say this, but Thanks for the input CA I had a feeling that might be the case. I ordered the parts for him from Certified Parts Corp. When I pulled the carb apart up in Michigan a few weeks back I noticed the rubber tip on the inlet needle was damaged, so he's getting a new one along with a pump element. (It stared flooding on us)

Wish I could post a pic of his boat. John Deere green & yellow. Sure turns a lot of heads on the road. Looked best when we took it to the back lake with my father0in-laws JD tractor! LOL

Once he gets that motor running decent he might take you up on your advice as he already had an offer of $500.00 on it. ($500 more than he paid for the whole rig & trailer)

Take care!
 

Steve M.

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Joined
Oct 21, 2008
Messages
3
Re: Pump Element on a Ted Williams 7.5TG

Here?s a question for the experienced ones (CATransplant and/or steelspike):

(Wish I had the dang carb here so I could pull it apart and find out first-hand, but it?s still on the boat up in Michigan.)

Does anyone know off hand if this carb has a replaceable rubber seat? The Sears/Eska originally had a Viton-tipped needle with a tiny spring that sat on top of it, similar to a very short ball point pen spring. Received a new needle from Certified Parts today (along with the pump element) and although it?s the right p/n its a solid aluminum needle.

To the best of my knowkedge, solid aluminum needles are designed for use with replaceable rubber seats and Viton-tipped needles are usually found in carbs with non-replaceable seats.

BTW, I spoke with the owner of CPC. He couldn?t answer, but the substitute needle has the spring built into the needle itself instead of the little round one that sits on top. No wonder Tecumseh went to a new design. It must have cost a fortune to make these.

Thanks guys!
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Pump Element on a Ted Williams 7.5TG

Early carbs viton needle seats into the carb body.Later carbs have a removeable viton seat that can be removed with a wire hook.These carbs have some involved procedures that if you need to do you should work from a manual.I may be able to email a page of my manual.if I can get my scanner to work.You could pm me your address.
 
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