Tecumseh Timing problem

[web4xn]

Hello everyone ...First timer here!!!! Have a question on a Tecumseh engine..... Here we go......I picked up this mower the other day for free thinking I could fix it and have a free mower ...HA HA HA !!!! Tricks on me!! The mower blade hit somthing very hard and broke the blade adapter and bent the blade. I pulled all broken pieces off and tried to start the motor it backfired through carborator jerked the pull cord out of my hand and ripped off 3 fingernails...ouch!
I figured the timing was off so I pulled off flywheel and found keyway was sheared and replaced with a new one. Put mower back together thinking that everything was good, gave it another good pull to start and ripped off last 2 fingernails...
Tore motor down to look at eternals to see if maybe timing was off inside and found all timing marks lined up and good nothing looked broke or displaced inside the motor. Put everything back together and still firing before top dead center and trying to rip my HAND off. Anyone out there with any ideas....the free mower is turning into the project from !!!
Thanks for any help that you might have for me.

 

[jr dragster T]

I had the exact same mower and probelem even with a new timing key. your probably not torqueing down the flywheel tight enough or the taper on your shaft is messed up.

 

[web4xn]

What would cause the timing to retard or advance if the keyway is back in alignment Thanks

 

[Russ2251]

Is blade still off engine? If so, this would cause starter cord to rip out of your hands. Blade acts as a kind of flywheel that aids in starting. Vertical shaft engines have lighter flywheels to compensate for weight of blade. Put another blade on and it will run like a...well...a lawnmower.

 

[jr dragster T]

If your sure the key is in properly and the timing is retarding or advancing then thats pretty weird. If you cant figure it out I think there was a reason for it too be free...so it can rip somone elses wrist

 

[web4xn]

Thanks for the advice The weight of the blade makes sence Thanks for your time .....and i will let you know the out come

 

[Russ2251]

Make ABSOLUTELY SURE crankshaft is not bent first.

 

[Russ2251]

Tore motor down to look at eternals to see if maybe timing was off inside and found all timing marks lined up and good nothing looked broke or displaced inside the motor.

Internal timing cannot change or 'jump' unless gears were timed improperly to begin with, or stripped, which would be near impossible with engine still intact. If it is known that engine was never disassembled, valve timing won't need to be checked (unless it's Over Head Cam).

Put everything back together and still firing before top dead center

This is normal.

 

[web4xn]

Great idea !!!! I will keep the kids in the house for my first start up!!!!

 

[Russ2251]

Great idea !!!! I will keep the kids in the house for my first start up!!!!

I would not start it until I checked it. If it throws the blade....need I say more?

 

[web4xn]

YES !!!!! I will check and make sure crank is not bent befor start up would hate to lose a foot or worse!!!!!!! Thanks for all the input I will let you know:biggrin5:

 

[mckutzy]

Is blade still off engine? If so, this would cause starter cord to rip out of your hands. Blade acts as a kind of flywheel that aids in starting. Vertical shaft engines have lighter flywheels to compensate for weight of blade. Put another blade on and it will run like a...well...a lawnmower.

hello people new guy here on the forum, i just saw ur post here and was wondering if the blade when taken off could be replaced with a fly wheel of some sort and simular weight but a smaller dia. I have figured out a twisted V belt setup to use a vertical shaft for a mini chopper.

anyways glad to be here and see great stuff too....

 

[oscaryu1]

It depends. Some engines use the "flywheel" just as a cooling fan, and the blade to make up for it... some are the opposite.

 

[Russ2251]

It depends. Some engines use the "flywheel" just as a cooling fan, and the blade to make up for it... some are the opposite.

Can you rephrase that? I'm a little slow.

 

[kibble]

No, Russ, you're not slow. I don't get it either..either that or we're both slow... :arf:

 

[oscaryu1]

Can you rephrase that? I'm a little slow.

Well I've read that some flywheels are really flywheels, so the blade makes no difference, while the "flywheel" on other engines are just used as a cooling device, and the blade as the "flywheel".

If you don't understand, screw it

 

[mckutzy]

i could understand that the blade counterbalancing the motion of the engine flywheel spin, for me if this is the case of genning a hand ripped off, im thinking i might just make a fly wheel for the blade end. i can grind and balance it at work. what is the weight of a blade?

 

[I like karts]

I guess mowers are just set up to have really advanced timing or something...

 

[Russ2251]

I guess mowers are just set up to have really advanced timing or something...

Nope...If anything, less so.

 

[Magice]

i great idea when trying to start a backfiring mower is 2 tips:

unhook the recoil cord from the handle so its right from the engine, alot easier to start.

also, wrap a kitchen towel around the handle when you pull it, that way it doesn't rip your hand off + the cloth comes out. I've had a bad experience with my last mower.