Your starting problem is the classic symptom of your ignition coil failing. It may take a long time for it to completely fail. I've had the same hot starting problems on a couple three Lawn Boys.

Don't know about the self propel though.

Thank you for the fast reply. Much appreciated! I hate show my lack of knowledge...but is an ignition coil the same as the 'C.D. ignition pack' (electronic ignition) on the parts list?

Don't see any reference to an ignition coil.

I did figure out that the carb bowl removal is just 4 screws. Even I can handle that!

Thanks in advance.

Yes, the CD ign. pack is what you should replace. Make sure you properly gap the new one to the coil. Methinks it is a very common failure on the

The neat thing about Lawn Boy's is you can get an electronic version of the service manual from lawnboy.com for free. That may also help your SP problem.

Well, you have a 35 y.o. motor....so I think it's a compression issue ......I have been wrong in the past ,but I was mistaken:o)
The CDI (Capistor discharge ignition) unit are noted to fail,rust,improper gap (from a loose crankshaft journal),will change the spark timing and voltage...Clean the flywheel magnets,and the legs of the CDI pack,and have the airgap set at .010" of an inch....also check for end play on the blade side of the crank shaft ,back and forth or side to side movement is a bad thing....
The carb is easily cleaned by removing the intake reed valve assembly from the block(4-7/16 hex screws with phillips screw heads in them also) and then removing the carb bowl (inverted carb)for inspection and cleaning while the carb is still attached to the reed valve assembly,(be sure you install the float and needle the same way it came out(carb still inverted))there should be a fine screen cylider shaped filter surrounding the main jet,once that is removed you should be able to remove the main jet,with a reg.screwdriver,inspect it and clean it and reinstall it,the screen and the bowl without mush mess....you should use a new gasket between the reed valve assemby where it attaches to the block.see ya Jim

Do you have any oily buildup on the muffler that looks fresh?
Check the top side (towared engine) for any fresh oily residue from the shaft area. The lower seal could be bad. Like jim said I think I'd check out any loss of compression. The lower bushings wear out and that causes crank shaft end play and it streches out an already 35 year old seal causing compression loss. You need all the compression you can get to start the engine so air will suck through the carb and into the combustion chamber with the fuel vapor causing an ignition explosion.

You could check the gap on the CD pack and flywheel. It should be .010 Use a feeler guage or a business card that is .010 or else you could be setting it to far so some say. I've used a business card successfully on many coils though.

Neal

Thank for the replies guys! I only wish my knowledge and experience were better.

I just ASSUMED the CD Ignition pack was a bolt off/bolt on thing. This measuring the gap to the coil part has me a bit..hesitant..:-).

You have to place yourself (low) at my level..I have done only basic maintainance, I have a pile of ebay parts, a shop manual, and precious little experience actully taking things apart. I'll have to look at the book some more.

Picture a rookie surgeon staring at a book while standing next to the operating room table, and you get the idea..

I was taking a close look this past off season at the possibility of a worn lower bushing issue, due to vibration. Turned out to be only a bad blade re-sharpening at the shop (they did two blades, both equally as bad)- I bought a new blade (on a hunch) and that cured that.

While investigating that, I found no side play at the bottom end. A slight oily residue has always been there, seems for decades. While I can't totally rule out compression/lower bearing, I suppose a better shop can measure the compression?

So, ignition pack? Compression? Little of both? Hmmmm...

Well at least I today I scored a pair of self propel axle sleeve bearings, as well as a pair of R and L roller pins. That should take care of the axle hop-I think.

Did some reading, and now I have an idea of what the air gap is all about. I think I cn measure the gap easy enough for a starting point.

The air gap is a breeze, just use a 5/16 socket or nut driver, loosen the two nuts and place a feeler gauge or similar.010 gauge in between the flywheel magnets and the CD pack, tighten and your done.

Neal