Almost impossible to pull starter cord

[docrocky]

Sears Suburban 10 garden Tractor with a 10 HP Tecumseh engine. Reconditioned the engine by taking off the head, redoing the valves, seals, seats excellent, cylinder and all excellent. Have excellent compression and with the spark plug removed pull rope has no trouble turning the engine with excellent compression, etc. But when we replace the Plug, I can barely pull the starter rope. It does move but I use all my stamina after 4 or 5 pulls and it will not fire. I understand most modern small engines have a compression relief to allow easier starting. Has anyone ever tried removing the recoil starter and using an electric drill with a flat disk torquing against a similar disk like a clutch plate attached to the crank shaft. I am thinking about the small starters we use on model airplanes by pressing a rubber cone over the prop cover to get those small engines to start.
I don't want to get too detailed with this because the tractor has only a very minimal usage as pulling a small Sears self propelled rototiller to be used for crop cultivating weeds. I have other tillers for the ground prep that my bigger MF 300 will take care of. Any recommendations?
Thank You
I also did some earlier posts on the same tractor you might refer to.

 

[tcartwri]

You're confident that you set the valve clearance properly?

 

[docrocky]

Thanks Tim: We had to trim the valve stems down to set the valve lash according to specs. I may have miss stated , I can pull the cord and it does move freely with the plug in but it is tight. I even tried using gas with the 2 stroke oil additive (weed trimmer) but no read difference.

 

[KennyG]

It's not clear, but did you put in new rings? If so were they the correct size? Sounds a little like oversize rings. My experience is that large Tecumseh engines start hard. I have an 8 hp that runs fine but I can only start it with starting fluid.

 

[Ken]

For a short while had a Sears 10 h. p. garden tractor it was given to me and very hard to pull to start.
after working most of one morning and could not start. a neighbor that was a mechanic came over to watch and explain what I was doing wrong. he sprayed in some either and pulled the cord it back fired and almost took off his arm . The next person interested in it I gave it to him and this was about 20 years ago and never has he mentioned the gift.
ken

 

[bigtiller]

I have a 5 hp Briggs that is very cold blooded. I took the starter rope recoil assembly off and start it by turning the crank with a 22mm 12 sided socket attached to a cordless drill. If you have never done anything like this before, be careful the socket doesn't stick on the crank when it starts.

 

[ray66v]

This is classic Tecumseh. They once made a decent product, but everything they made at the end was questionable.

I have a 10 hp Tecumseh powered chipper, that is exactly the same way. It is almost impossible to pull start it. It takes two people, one to stand on it, and one to pull the starter with both hands, and then it barely turns over.

Conversely, my 11 hp Generac generator, is almost effortless to pull start.

 

[Willl]

a neighbor that was a mechanic came over to watch and explain what I was doing wrong. he sprayed in some either and pulled the cord it back fired and almost took off his arm .

Almost sounds like a slightly sheared flywheel key.

 

[Barry 1]

Pull the head off,turn it over by hand and see if the compression release is opening the exhaust valve slightly (.030??) on the compression stroke.If there is too much clearance on the exhaust valve,it won't work.If the spring on the cam is missing,or the pin is worn down,it won't work.

 

[Ken]

Almost sounds like a slightly sheared flywheel key.

it did have a different type of ignition . but since I passed it on and never saw again can give no update to the problem.
Looked like would of been a good garden tractor if had a starter and battery.
ken

 

[docrocky]

KennyG: No, we did not do anything to the piston or cylinder since they were in excellent shape. The pull was difficult even before we got started on the "redo", basically no change. Like I mentioned before, with the plug removed, it pulls with ease. I see reasonable spark, Have tried starting fluid both in the cylinder as well as thru the carb. Also a small bolus of gasoline into the cylinder, but still no success. I even tried the cordless drill with a make shift rubber clutch against the housing of the recoil/flywheel, but it can not overcome the resistance that the cord pull can deliver.

 

[Hooked_on_HP]

I am not sure about Tecumseh but most of the larger single cilinder engines have an automatic compression release. It is usually on the camshaft and opens the exhaust valve early to release some of the compression so you can crank it.
Bill