# hm80 tecumseh driving me batty



## teds1 (May 20, 2006)

hi all

i have got an noma snowblower with a 10 hp tecumseh... i live in snow country so its a must to have and more importantly run properly.

to the point i was given this machine and it was not cared for previously but i got it to run and run well. i did about 3 hrs of snow removal with her and when done it would not restart. towards the end it backfired a couple of times but continued to run.

i have read all the posts on the tecumseh in here and learned a lot about her.. my experience mostly with briggs.

anyways i cant get her to start cough or sputter ...

i have done the following...

rebuilt the carb.. it was really nasty.. so nasty i ended up getting a new one...
changed the fuel lines....
new spark plug...
also put a new gear on the drive system.. the old one was plastic.. i know not engine related but what a joke...
i have checked for spark.. i thought i have good spark... seem to have good compression...
pulled the head in case i blew a gasket.. gasket ok... but valves look dirty i will clean them up today....

BIG MISTAKE ON MY PART
when i changed the gear on the drive system i tilted her up and didnt shut off the gas line and gas drained into the oil.. a fair bit... brutal mistake.. i kicked myself for that stupid one...

anyways.. cranked her.. then changed the oil...oil seems okay now..

pulled the flywheel and the points seem okay but i will replace today... but more importantly one of the magnets off the flywheel has come off.. i will try and epoxy it back on today...... flywheels are expensive... but maybe a replacement is due...
also checked all the kill wires etc.. they work fine...

ANY OTHER SUGGESTIONS OUT THERE TO MAKE HER FIRE... I AM THINKING THAT THE TIMING IS MESSED UP THATS WHY NO FIRE OR SPUTTER.... I HAVE SPARK JUST MAYBE NOT ENOUGH AND OUT OF TIME....

ALSO THINKING ABOUT AN ELECTRONIC IGNITION IF NOT TO EXPENSIVE OTHERWISE NEW POINTS AND CONDENSER...

AM I ON THE RIGHT TRACK OR CAN ANYONE OFFER SOMETHING I HAVE MISSED...
THANKS


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## bsman (Jan 22, 2006)

have you looked at the flywheel key at all? could be sheared, and not making it rn, or not running good...could be out of time, but that would be the last thing id check.


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## 30yearTech (Sep 14, 2006)

If the magnet on the flywheel is not in its correct orientation that could be causing a timing issue with the spark, I have tried to glue magnets back to the flywheel with limited success. My guess is a new or good used flywheel, maybe find a similar model engine and try the flywheel off of one to be sure if you can.

Best of Luck...


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## teds1 (May 20, 2006)

Yes Checked The Flywheel Key And Its Fine... And Pretty Much What I Figured About The Flywheel Magnet Affecting The Timing... I Will Post More Later Today And See How My Success Went With Epoxying The Magnet On...
Thanks


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## briggsrepairman (Dec 12, 2006)

Yup,
I agree, the magnet not being in the correct position,even by a hair could trigger the timing to be off, thus backfiring. I wouldn't count on epoxy working due to the tremendous centrifugal force and heat. If you look on Ebay, people sell engines and parts dirt-cheap for these things, so take a stab at that.

In the slight chance that you DO get the thing glues back in, you can reset the gap between the flywheel and magneto. The easy way is to loosen the 2 screws holding the mag on slightly so the mag will move, then place a business card between the mag and the magnets. This will cause the mag to get stuck to the magnets, but the business card between the two surfaces will be the correct gap. tighten the screws and remove the card. wallah! the gap between these two components is important. also- make sure that if you glue that back in that the surface is totally flush.


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## teds1 (May 20, 2006)

epoxed the magnet to the flywheel and stuck pretty well.. however i was concerned about the exact placement.. so after going from shop to shop got a new used flywheel and installed it..

i also put new points and condenser on it.. does anyone know exact way to gap these..

i put piston to tdc and set the gap that way.. but i see in some manuals you have to use dial indicators etc.. to set it while piston is btdc.. seemed to complicated for me ..

i put all back together... and got the machine to cough,,, sputter but not run... also gas fumes coming out of exhaust...
a new carb also...
anymore ideas... 
i will fiddle with carb presets.. and check float play on carb.....
spark seems okay.. wet carb also...
what am i missing...
i also took of the head and cleaned the valves.. a little carbon build up but nothing too serious...

any suggestions on getting it going...


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## teds1 (May 20, 2006)

hi another update still cant get it to start.. it will cough and sputter its trying but to no avail... messed with the carb settings forever...

so finally i broke down and put it in the shop... hopefully just a couple of days... i will update when i find out...

thanks all....


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## briggsrepairman (Dec 12, 2006)

*More little things you can do.*

I'll throw out a few more things you can do that have given me problems, particularly on Tecumsehs. One thing is that if you notice it will have 2 linkage pieces. One with a spring, the other a solid wire. The spring is easily stretched and if it is, that can cause the engine to be difficult to start. Secondly, as simple as this sounds, make double sure that the brass bolt that holds the bowl on the carb is clean. That means checking the pin holes on the side in the threads and even the one on the bottom if it has one. Next, make sure the needle is seating properly. These tecumseh carbs have a little bendable flap where the needle seats. You can tell if it works by gently pressing up and down on the float. If it goes down and gas comes out, then it is working. Likewise, it needs to shut off when pushed up.Also- make sure there isn't any holes or leaks around the primer bulb. That'll cause the engine to flood. I've also noticed that some Tecusmeh engines will not run unless the sir filter cartridge is in place. It is integral because it forms a partial vaccum which the carb needs. This seems especially true in newer carbs with the plastic floats.
Setting the timing isn't that exacting on the points. The shade tree mechanic way that works for me is to turn the flywheel until the gap on the points is open all the way. Then slowly turn the flywheel until it starts to close again. Then turn it back until they open again. That way you know that you are setting them when the piston is set TDC. Set them for 0.20 or whatever the specs say. Then make sure the magneto is set right, as mentioned previously with a business card. 
Last but not least, sometimes I have found that Tecumsehs are sensitive as far as what spark plugs will work for them. In briggs, it seems like I can throw in anything. With Tecusmehs, I've found that if you stray from what it came with, they will NOT run at all. make sure you have the right plug.


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## teds1 (May 20, 2006)

hi all 

here is the update .. got my snowblower back from the shop it turns out there were multiple problems all minor that contributed to it not starting ..

the flywheel was bent.. that one i cant figure out or could have fixed.. it was a replacement anyways for the original one....
replaced the spark plug... did that anyways..
reset the points.. i guess i was off by a bit..
reset the carb...
decarboned the intake and valves...

the service guy was good and got it to run.. and thats all i wanted really,,, i am glad it was not the timing... i checked out how to set the timing on the web and here and it seemed a little too indepth for me and i dont have the tools anyways...

the machine is still not set up right as far as the carb is concerned... the manual says to run the machine full open and adjust the main line in until sputter and then back off till sputter and set inbetween the two points...
the idle mixture is to be set while machine is running at idle.. and the same procedure as above...

does everyone concur... 
and thanks again.. tons of help here..

oh by the way... no snow up here in canada to blow yet... go figure...


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