Tecumseh sputter, worse under load!

[formariz 11,849]

Here is timing procedure for Tecumseh engines from Brian Millers site; Great simplified description on how to do it. I always follow this one.

 

First of all, on virtually any spark-ignition engine, advancing or retarding of the ignition timing is performed by widening (advancing) or narrowing (retarding) the ignition point gap, and on Tecumseh engines, it's also performed by rotating the ignition stator (the aluminum part the points, condenser/capacitor and coil are fastened to) one way or the other. On all aluminum block flathead Tecumseh engines, the entire ignition system is located under the flywheel. (There is no points lobe on the camshaft.)

Using a feeler gauge, set the ignition points at 020". NOTE: Be sure the end of the plastic lever arm is on the highest side of the rubbing block (points lobe) in alignment with the arrow (6). And make sure that the feeler gauge, points contacts and rubbing block are absolutely clean! Also, apply a small dab of automotive grease on the rubbing block to prevent the plastic lever from wearing.

With the cylinder head removed, for all Small Frame engines (up to the small block 5hp; including all walk-behind lawnmowers, some small snowblowers, garden tillers, etc.), rotate the crankshaft in normal rotation (clockwise when facing the flywheel) until the piston is positioned at .070" BTDC. For all Medium Frame 5hp [big block] and 6hp cast iron and aluminum block engines, position the piston at .050" BTDC. And for the Medium Frame 7hp, 8hp and 10hp aluminum block engines, position the piston at .090" BTDC. To position the piston at the correct height in the cylinder, use a dial indicator or a large flat washer of either .050", .070" or .090" thickness placed on top of the piston with the piston even with the cylinder deck height.

Slightly loosen the two stator retaining bolts, and rotate the stator by hand JUST when the points begin to open. It is at this point when spark occurs. Do not rotate the crankshaft to do this! You can visually see the points open. But for a more accurate setting, use an ohmmeter (d) (make sure the battery is fully charged) or a battery-powered test light in the points only (the points will act as a switch to turn the light off and on).

Tighten the stator bolts and the ignition timing is correctly set.

NOTE: If the ignition timing is set correct and the engine kicks back upon starting, sometimes, but not always, the compression release mechanism on the camshaft isn't releasing enough compression from the combustion chamber. When this happens, try setting the valve clearances to specs (.008" intake / .010" exhaust) and see if that makes a difference. If the timing is retarded to reduce the possibility of kickback, then the engine will be hard to start, run sluggish and not produce adequate power.

 

Here is link to actual site http://gardentractorpullingtips.com/ignition.htm

Lots to read and learn from in addition to great reference information on parts #s. I am on it all the time.

 

Here is also a good reference video for it. Nothing like watching someone do it. 

 

[Team70R 157]

Awesome thank you! I got the new coil on, pulled the plug and grounded it on the head and it is still doing the same thing. Only sparks when it wants to. I can feel it if I grab the plug but it's very weak..  help!! Haha

Does the condenser need to be in full contact with the mag here?

[Team70R 157]

Got the spark back by moving the condenser to contact the stator.. but it still won't rev. Just sputters and smokes 

IMG_2434.MOV

[formariz 11,849]

I am not sure you got the correct condenser. Should be screwed down on stator so it is properly grounded otherwise it will not work right. There is a specific condenser for that one. Let me see if I can get you a # and photo of it.It is an h60 you got correct?

[Team70R 157]

Correct. It is screwed down underneath as well! The coil ground wire is also connected with the same screw. I bought the condenser for my old hh60 and never used it 

[formariz 11,849]

Lets see. New condenser, points ok, new coil, new carburater. Still same condition ? Did you get to check timing on it yet?

[6bg6ga 271]

https://www.harborfreight.com/timing-light-with-advance-40963.html

 

It doesn't have to be a SUN or other high dollar light. Got one of the old unpowered timing lights? May have to run the machine into the garage to get out of sunlight to use it and those straight connections to the spark plug wire can zap you when you forget its not an inductive pickup but will still work. The harbor freight link will steer you to a cost effective light or you may possibly have a car parts store that will loan one out.

[Team70R 157]

6 hours ago, formariz said:

Lets see. New condenser, points ok, new coil, new carburater. Still same condition ? Did you get to check timing on it yet?

Gonna try to check the timing tonight. May have to get a light if I can't get it set 

[Molon_Labe 731]

Wes, have you checked the flywheel magnets to make sure they are firmly in place? The main reason the timing is so critical on these things is that the points must break at the exact same time the coil reaches peak voltage. If you have a spare flywheel you might try swapping them to see if it makes a difference.

[Team70R 157]

11 minutes ago, Molon_Labe said:

Wes, have you checked the flywheel magnets to make sure they are firmly in place? The main reason the timing is so critical on these things is that the points must break at the exact same time the coil reaches peak voltage. If you have a spare flywheel you might try swapping them to see if it makes a difference.

 I checked be magnets and they are still firmly attached and have good strength. I thought about trying a different flywheel wheel. I've got a spare I'll put on if the timing doesn't fix it. 

[Team70R 157]

Well I feel like an idiot for not checking it sooner but the timing was way off!!! Points were opening after TDC advanced the timing as far as possible and it runs great!! Just need to adjust the Rpm now!

[Molon_Labe 731]

1 hour ago, Team70R said:

Well I feel like an idiot for not checking it sooner but the timing was way off!!! Points were opening after TDC advanced the timing as far as possible and it runs great!! Just need to adjust the Rpm now!

Wes, glad you got the old girl going. As you have learned, there is not much room for error on these old Tecumseh's! When they are dialed in, there is nothing better. Congratulations!

[Team70R 157]

3 minutes ago, Molon_Labe said:

Wes, glad you got the old girl going. As you have learned, there is not much room for error on these old Tecumseh's! When they are dialed in, there is nothing better. Congratulations!

Thank you, Major! It's definitely a good feeling! And another lesson learned!

[Molon_Labe 731]

Forgot to mention, when they are not dialed in... well you know the answer to that. Tecumseh made great engines, however, the ignition systems and carburetors were "marginal". When everything was set to specs they were (are) as good as anything offered today.

[Team70R 157]

I agree!!! Just takes time and patience!