# Tecumseh HM80 155169E9(1989 Toro)



## BlueBlackBird (Jan 22, 2014)

Ok, bought used, ran fine but it didnt really idle, cleaned and did the rebuild carb route. Yesterday, it started 2nd pull but was running very high RPM, it was either fast or off! Then started to pop and backfire. Today took carb off , cleaned reinstall, hard to start, will run for awhile but only half throttle, but then starts to miss and backfire and pop. Then it will stall out, and it is very difficult to restart. Getting spark, getting gas , Im pretty sure I have the linkages hooked up correctly, butterfly, and governor. New gas, cleaned out fuel tank, Im stumped, and it is going to snow tonight and tomorrow!!! Any suggestions?
Thanks


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## motorhead64 (Dec 15, 2013)

Is this a fixed jet carburetor, or do you have adjustment needles for high speed and idle? MH


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## BlueBlackBird (Jan 22, 2014)

not fixed jet can adjust both idle mixture and high speed, have the HS @ 1and1/4 out, idle mix @ 1 turn out


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## motorhead64 (Dec 15, 2013)

When you cleaned her, did you pay close attention to the little transverse holes in the high speed jet's bowl nut? If so, are you seeing any change in running quality when you adjust the high speed needle? MH


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## BlueBlackBird (Jan 22, 2014)

I put in new jet, but I did not notice those holes, I just checked on the old one and I noticed a little tiny hole on one side, , so in the morning I'll tear it off again, and do some thorough checking.


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## motorhead64 (Dec 15, 2013)

Most have 2 holes...a tiny and a teeny tiny. With my old eyes, I have to use a magnifying glass to see them. They have to be clear all the way through. MH


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## HCBPH (Mar 8, 2011)

*Carbs*

Those holes are small and accessible by holding the throttle open by hand. I take a piece of phone wire and bend a hook on the end and can check them to insure they're open.

Did you check that you have all the springs and parts hooked up correctly for the governor to choke? I also typically clean them up to remove any old buildup on them. Sometimes if improperly assembled or gunked up, it can hang up the throttle.


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## BlueBlackBird (Jan 22, 2014)

Thanks, I have a good blowup of the spring, governor attachment and carb that I found on another site(Smokestack). Here goes another disasembly.


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## Shryp (Jan 1, 2011)

Here is a good reference site:
Disassembly, Cleaning and Repair of Tecumseh (Lauson) Series 3 Carburetor 632334a

And another good place to stop:
donyboy73 - YouTube


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## BlueBlackBird (Jan 22, 2014)

*Continuing saga of Tec HM80 155169E(Pop and Bang)*

Ok, 2 days ago took off carb and cleaned AGAIN. Reinstalled new carb kit. Set everything up( initial settings). Yesterday, thought I would replace gas line and put a new shutoff valve (The one that was on was nice but too industrial and long , so it looked like it was pinching), took out the little red plastic fuel filter, and added NEW,FRESH GAS(even though the older gas was only about 2-3 wks old) octane 91(no eth). Guess what???? Started 1st pull and ran like a charm, except under load it was a bit low on the RPM but still cleaned the long drive.I have to fine tune , maybe tomorrow.
The moral, FRESH GAS!!!!!!!!! seemed to be the problem and maybe the f.filter


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## Shryp (Jan 1, 2011)

I merged your threads together. Please try to keep updates to problems in the same thread.


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## ranvette (Jan 5, 2014)

I sugjest putting a tiny tach on any of these blowers.You can get one for about 20 bucks on ebay.This way you can set your max rpm to 3600 for tec engines.I tend to run my ariens 8 HP at 3000 to 3100 rpm in recent 1 foot of snow.Than i run bursts of 3600 rpm here and there while useing it.Makes for real fun and you can monitor your rpm drop under load.It will give you a real good idea of how strong your old tec engine is to.Look for a drop of about 150 to 200 rpm or so under full load in normal type snow.And best of all you can set max rpm at 3600 which is desighn spec for the old tec L heads and know your safe.I also found thes engines really power up at the 3600.Most seem to only run around 3200 or 3300 as factory set.I set up both my old 6HP and 8HP with tachs.Works great for carb adjustments to.They both run much better and put out more power tach tuned.If anyone buys one make sure you get the tach with a separate ground wire those work best


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## Big Fish Billy (Feb 6, 2014)

Couple other refinements you might like to do. Once you get it running fairly well, buy some Deep Creep Seafoam and spray enough in while it's running to stall it out after about 15 seconds. Let it sit an hour and then restart and enjoy the smokescreen from the carbon burning off, usually to blame for excessive popping. IF you had a lot of smoke, repeat the process until it doesn't smoke. Then add an ounce of regular Seafoam to every gallon of fuel, it helps keep the motor clean and running well. Whenever I have a problem with these small engines, I always change the spark plug, it is amazing how fast the foul when they are wet with fuel or oil.


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## BlueBlackBird (Jan 22, 2014)

Thanks, the tach idea sounds interesting , do you have it mounted or portable? I did put in a new plug also. I do use Sea Foam in the gas, in this tec engine as well as in my Honda cbr1100xx I havent tried the SF Creep.


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## ranvette (Jan 5, 2014)

I have it mounted up by the controls on velcro.You could just use it portable to do the set up and take it off the machine.All you need to do is wrap 1 wire around the coil wire and put the other to engine ground.It keeps track of your run time hours to.


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## threeputtpar (Jan 16, 2014)

It sounds like you may have your problem fixed, but for anyone else searching and reading I had all of the same issues on my HM80 and it ended up being solved by pulling the head and de-carboning the combustion chamber.

I fired it up and it stumbled for about 5 seconds and then smoothed right out and ran great for the next 10 minutes. I shut it down and now it waits for the impeller control cable to arrive and then it will see its first action.


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## Kiss4aFrog (Nov 3, 2013)

_*the older gas was only about 2-3 wks old, The moral, FRESH GAS.

*_I just can't buy that one. If the problem was the high RPM as you said "fast or off" I believe the second time you pulled the carb you assembled the linkage correctly. Not that the fresh gas solved it. I think the linkage was off a hole or two the first time.
IMHO There just isn't any way gas ages that fast to cause a problem even it it does have ethanol and isn't treated with anything.


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