Sears Eska 7.5 HP Carburetor Parts and Running Issues

[CurrT]

Hello everyone,
I posted in another thread and was advised to start my own thread instead so here goes. I have a Sears-Eska 7.5 HP Motor AV817-640-02, Tecumseh Carburetor P/N 631648. I am looking for an Inlet Viton Tipped Needle Valve P/N 631505 and a small inlet valve spring P/N 631506. I have been unable find these two parts for several weeks now and was hoping someone here may know a source. Attached is a photo of the two parts assembled.

The other member indicated that I might be better off with an all metal needle valve. A rebuild kit that I purchased for the carb gaskets had an all metal needle valve, a clip/spring and a separate seat but when I attempted to use those with the carburetor on the motor, the needle valve was too long/high.

Looking for some direction and advice on this motor, carburetor and the issues.

 

[brim_buster]

Heres my reply. Ive rebuilt numerous eska motors with kits Ive purchased off ebay and NEVER had an issue with the all metal needle. I mean NUMEROUS. Your not doing something right. Did you take the old needle and compare to the new one and did you get the right kit?

 

[brim_buster]

Eska Sears Ted Williams Tecumseh Outboard Motor Carb Carburetor Kit 1961- 1987 | eBay

Eska Sears Ted Williams. This kit fits most Eska Engines. Tecumseh Outboard Motor.

www.ebay.com

 

[brim_buster]

That power head was used from 1972 to 1985 in a 7 and 7.5hp. Got a model number should start with the numbers 217 lets see what were dealing with here

 

[CurrT]

I purchased the kit on Amazon and it is found here:
https://www.amazon.com/dp/B07CSQGMNJ?psc=1&ref=ppx_yo2ov_dt_b_product_details

I believe that I got the AV817 out of an Eska Mechanics Manual but after looking at the manual again tonight I am not sure why I got that except that to say that I have been cross referenced stir crazy on this project. My apologies for the error. The plate attached to the motor has a faint T then 640-02. I keep coming across model number 217-58820 relating to this motor (Sears Parts Direct and other forums).

My plan is to try the all-metal needle valve that came with the kit I purchased tomorrow as we discussed one to one. The all-metal needle valve that came with the kit is longer than the Viton tipped needle valve that came out of the carburetor.

My motor looks exactly like the photos included on following Ebay page except that the propeller on my motor is metal and is green in color.
https://www.ebay.com/itm/314044212711?nma=true&si=R6wClRgfhkPW6DSd%2FGS%2FAAdhsTQ%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

I truly appreciate your help on this.

 

[CurrT]

Found the model number label on the motor. It is 217-58820.

 

[CurrT]

Hey brim buster, it worked!!! Never in my wildest dreams would I have thought an all metal needle valve seating against a metal valve inlet WITHOUT a rubber seat of any kind would get the motor running but poof, it did.
Motor runs slightly rough but not enough to stop me from putting it on the water.
Next up, tuning and timing!
Brim thanks man! I greatly appreciate your advice and help!!

 

[brim_buster]

you shouldnt have to time it at all. Did you notice the manual I attached to this thread? Look at it will save you alot of trouble

 

[jbcurt00]

@brim_buster please remember that unless you hold copyright, don't post manuals.

Deleted a couple posts

 

[CurrT]

Brim, the motor is running decent at slower speeds but seems to lose power and runs rough with throttle wide open. Based on your input I see that there is a high speed mixture adjustment on the bottom of the carburetor cup. I will work on that to tune the engine based on information that I have found on the internet and that you have provided.

 

[CurrT]

Follow up: There is no high speed mixture adjustment screw/bolt on this model carburetor. I assume that this is a model with high speed mixture fixed. I will keep digging.

 

[brim_buster]

@brim_buster please remember that unless you hold copyright, don't post manuals.

Deleted a couple posts

yes sir

 

[brim_buster]

Follow up: There is no high speed mixture adjustment screw/bolt on this model carburetor. I assume that this is a model with high speed mixture fixed. I will keep digging.

Did you check the points? I dont think thats a solid state model. Is the float set correctly? How is your spark? Are you sucking air anywhere? Do you have an in-line filter between the tank and the carb? Thats a necessity.

 

[CurrT]

I have not yet checked the points. Not sure on the process to do this as yet. The float has been set set/calibrated correctly. Spark is solid. It is not sucking air that I can determine. I am using a Sears remote gas tank model number 217.59730/1 with a primer bulb in the fuel line. There is a fine mesh filter on the end of the fuel pickup tube inside the tank.

 

[CurrT]

Ok brim, I am in the process of tearing down the top end to check the points and have ran into a couple things one of which I didn’t expect. Firstly, I haven’t figured out how to keep the fly wheel from rotating in order to loosen the fly wheel nut. The manual refers to a special tool that I do not have. This one I think I can solve even if I have to go get some more tools!

Now to the unexpected. I found fresh fuel in the onboard gas tank. Not a lot, only about 1/3 cup, but that fuel had to have passed from the remote tank entirely through the system past the “closed” shutoff valve and into the onboard tank. I had a thought. If that shut off valve was not entirely “closed” couldn’t air from the empty onboard tank get sucked into the carb? The knob that opens and closes that valve used to turn really hard. I freed it up with WD-40 this morning. It seems to be opening and closing fine now.

 

[CurrT]

During the process of removing the flywheel I heard an air noise from the engine as the piston moves up and down in the cylinder when rotating the flywheel. Is the normal for these kinds of engines?

 

[CurrT]

I believe I have identified one of the last remaining issues (hopefully). The air hissing sound I was hearing when rotating the flywheel was air passing under and through the first engine gasket on the spark plug side of the motor. If I can find the gasket, replacing the bad one should be straight forward (hopefully).

 

[brim_buster]

I use an impact to take flywheel nut off. Tap lightly with a rubber mallet should get it to pop up and off. If you have the means to do a compression check it wouldnt hurt

 

[CurrT]

It appears that the motor has solid state ignition. At least I won’t need to be concerned with condition of points, point gaps and all that. Attached is a photo showing the ignition system.

 

[brim_buster]

Pray it never fails. Cant get them anymore but there are videos of guys re-working them when they fail. My 77 was SSI and it was a beast