# Need help for my Tecumseh hm80



## Julien Morrissette (Oct 7, 2017)

Hi,

I am having a lot of trouble with my engine.

a little history... last winter everything was going well but the carb got gunked up and so i ordered a new carb three months ago(same price as a rebuild kit) but it didn't work. My engine with the old carb would surge and not idle (common). with the new carb it won't rev up as it supposed to and will backfire/ flood somehow.
So as people suggested i checked valve clearance and everything around, changed spark plug, removed the head cleaned everything off to no avail.
so i checked the new carb and noticed that the welch plug inside the bowl was missing.

So i ordered another carb, still no welch plug. Tried the new carb and it does the same thing but i was able to adjust it somehow but now the governor arm pushes the throttle to idle to maintain a somewhat low operating rpm (it blows snow but the throttle is at idle so I can't idle the engine down and it's obviously not right).

So my guesses are:

1-somehow i didn't put the linkages to the right hole on the throttle arm when i put the engine back together?
2- i bent the governor linkage?
3- the governor is bad?
4- i really don't know what is happening

the picture was taken while the engine wasn't running you can see the throttle is opened , there is resistance if i try to push it to idle .









If someone can help please i would be grateful


----------



## Julien Morrissette (Oct 7, 2017)

you can see here how bad it's running and not really responding to adjustements 
at least if it's something in the governor i have two spare engine for parts


----------



## JLawrence08648 (Jan 15, 2017)

The Welch plug inside the bowl is bogus, it does nothing.

Is there a hole behind the one you are in? Not to the left or right, if so, that is the hole.

You have an adjustable carburetor, adjust it, bottom one is high speed, side is low speed.

Maybe you should watch a video or read and set the governor first! Then readjust the carb.


----------



## strtch5881 (Oct 6, 2018)

I think you are turning the screws too far, too fast. When you get close to running decent at high speed, turn the high speed screw in slowly until it starts to lose rpm. Back it out slowly until it smooths out. Then do the same thing at idle with the idle mixture screw. Turn each screw only a quarter turn at a time and let the engine catch up to the adjustment (it takes a couple of seconds).


----------



## Julien Morrissette (Oct 7, 2017)

the engine doesn't react to adjustements like it did when i repowered it. This video was just a demonstration of how bad it runs i just don't know what to do anymore. like normally i would go by ear and would listen to it going lean or going rich but now i just need help it doesn't work whatever i do. These engines are so simple yet sometimes you don't see the problem. 

Even When i fixed my brother snowblower i slapped on the adjustable carb, changed the governor linkage which was clearly bent and the mixture adjustment was so straightforward too


----------



## strtch5881 (Oct 6, 2018)

I know that the AM carbs are as cheap as a rebuild kit, but I have not had the luck that others have had. So I usually dunk the oem carbs in an ultrasonic cleaner and put a kit in. Unless the throttle shaft and body is wore out. Then I usually find a busted engine to rob the carb from.


----------



## Julien Morrissette (Oct 7, 2017)

I just watched again a governor adjustment video and saw that the governor linkage goes to the second hole from the top of the throttle. That must not be helping.
I might end up sending the original carb for a rebuild like many people say the am carbs might not be too good after all...


----------



## paulm12 (May 22, 2015)

here is my HM80 carb linkage:


----------



## db130 (Feb 16, 2013)

I usually have the governor rod attached to the 2nd hole on the throttle lever.


----------



## Julien Morrissette (Oct 7, 2017)

won't claim victory until i tried but it seems like we may have found one problem. You guys are awesome and stupid me for not taking more pictures before taking things appart


----------



## Toro-8-2-4 (Dec 28, 2013)

on the HMSK80 it s the 2nd hole as well. When you adjust the carb start with the idle jet and end with the high speed jet. You may have to cycle through the adjustments a few times. I have been using aftermarket carbs for years and never had a problem until this winter. If you can get a Tecumseh rebuild kit you are probably better off these days. The extra labor to clean it out is not extra compared to dealing with a defective carb. My thinking on this as shifted due to a drop in AM quality and now crummy shipping times. Even if they say guarateed delivery by some date. Dont believe it. No matter who the shipper is.


----------



## strtch5881 (Oct 6, 2018)

If you forget to take pictures, you can look closely at the original carb. There will be one hole with a slight amount of wear. The top edge of the hole will be slightly rounded.


----------



## Clutch Cargo (Dec 27, 2015)

Hope it works. Take another video when you get it sorted out. Hopefully going forward you are taking precautions vis a vis fuel treatment, shutting off the fuel and running dry, E0 etc. to keep the new carburetor from gunking up again.


----------



## Julien Morrissette (Oct 7, 2017)

yeah the carb was pretty dirty when i got it but was still working probably that the seafoam i gave the engine loosened some crud up overtime and too i noticed now the high octane gas now might contain ethanol in my area... 

And yes shipping was very much delayed they lost one carb in the mail now it was my 4 th order for that carb lol


----------



## Toro-8-2-4 (Dec 28, 2013)

Julien Morrissette said:


> And yes shipping was very much delayed they lost one carb in the mail now it was my 4 th order for that carb lol


I feel your pain. Waiting on parts for as long as 3 weeks now with tracking not updated since the 16th. I am just buying local now and paying up. At least I know I am supporting local businesses. 

Happy Holidays to everyone!


----------



## Julien Morrissette (Oct 7, 2017)

Thanks everyone it works. Like i said these engines are so simple we don't see the issues that are there





I have 5w20 oil laying around should i use it in this engine? I changed car and no longer need 5w20 i guess i could use it in this engine to get rid of it


----------



## Oneacer (Jan 3, 2011)

I use nothing but 5W30 *Full Synthetic* in all my equipment.


----------



## Ziggy65 (Jan 18, 2020)

The Ariens 10000 series manual calls for 20 weight oil. I used to use it up until about 5 years ago, but switched to 5W30.


----------



## Julien Morrissette (Oct 7, 2017)

i think it'll be fine i will change it next summer anyway. Thanks again and let's hope for some snow soon. Normally we already have a foot of snow but we currently having an inch of rain.


----------



## Toro-8-2-4 (Dec 28, 2013)

Julien Morrissette said:


> Thanks everyone it works. Like i said these engines are so simple we don't see the issues that are there
> 
> 
> 
> ...


As far as I know all Techumseh snow king engines spec 5W-30. You might be fine with it but you will burn it faster.


----------



## JLawrence08648 (Jan 15, 2017)

I use Dino oil in mowers, only synthetic in snowblowers, however Dino oil can be used in the older 5hp Tecumseh engines.


----------



## Julien Morrissette (Oct 7, 2017)

Finally got snow. Shes blows very well and doesn't bog down.

She bogs down a bit when moving up to full throttle but it seems to be ok when the engine is warm. Probably could richen the idle a bit.


----------



## Julien Morrissette (Oct 7, 2017)

i received new carb kit and rebuilt the oem carb. now it runs like it used to. Took me 2 minutes to adjust it so i guess chinese carbs are really crappy


----------



## paulm12 (May 22, 2015)

glad you got it working well. I always try to clean and rebuild first. 

tx


----------

