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View Full Version : Tecumseh snowblower engine: High RPM issues


Glenn J
11-26-2005, 06:08 PM
The engine is on a Snapper 826 snowblower from the mid/late 80's. Luckily for me, it saw very little use from the previous (original) owner and has served me well for the past few years.

Last year, I noticed some fluctuating/sumbling at high rpms. It liked to have the choke one just a bit in order to run right. Only after the engine was good and warm, could I take the choke off.

Today, I pulled the bowl off the carb and gave it a good cleaning. After getting it all together, I could not get the machine to idle correctly. The idle kept going up and down...without me touched the throttle. That little arm on the block kept moving. I played with the screw under the bowl and the one on the side of the body of the carb. I'm now at a point where it idles good and the RPM stays constant when I move the throttle.

The problem now is, it won't run smoothly past say 3/4 throttle. Once it gets passed that point, it stumbled really bad. And sounds like it wants to die out. I'm not sure if I'm running too rich or too lean. Any ideas where to start?

hole in one lco
11-26-2005, 06:14 PM
what color is the smoke

Restrorob
11-26-2005, 06:43 PM
The adjuster on the side is for the low speed circuit and sounds like you have that one adjusted just fine. The one on the bottom is for the high speed. When screwed in it leans the carb. out, When screwed out it rich-ens the carb. I would suggest pulling the spark plug and look at it, If it's black and sooty looking replace it and start the engine and rev wide open then adjust the bottom or high speed adjuster screwing inward slowly and see if it smooths out. If it gets worse screw it back out until it smooths out.
These older carbs. had a non serviceable check ball inside, If it is clean and still wont run properly at any adjustments the carb. needs to be replaced.

Good Luck

Glenn J
11-26-2005, 06:53 PM
Thanks for the quick reply restrorob! Is that ball located in the bottom screw? I thought there was something in there when I took it out. I may have been lost in the shuffle. D'oh!

Restrorob
11-26-2005, 07:06 PM
Thanks for the quick reply restrorob! Is that ball located in the bottom screw? I thought there was something in there when I took it out. I may have been lost in the shuffle. D'oh!

No, It's inside a passage that can not be accessed for cleaning. It will get stuck in the passage and cause the engine to hunt and run erratically.

Glenn J
11-26-2005, 11:10 PM
Gotcha! I'll try the adjuster on the bottom of the bowl.

If that doesn't do it, does the entire carb need to be replaced?

Restrorob
11-26-2005, 11:18 PM
Yes, I'm afraid so thats the easiest way to go.

Glenn J
11-28-2005, 12:50 PM
Yikes! What's one of those run?

Restrorob
11-28-2005, 01:30 PM
Yikes! What's one of those run?

Probably somewhere in the 50 to 75 $ range if I had to guess, Not too bad to make a unit run and perform correctly. Continued use of any unit that is running incorrectly only causes more harm than good.

Glenn J
11-28-2005, 02:24 PM
I'll be adjusting it this week again. If I can't get it dialed in, I'll pick up a new one.

Too bad that spare carb I have from the old 12.5 Briggs won't work. :D

Glenn J
12-22-2008, 10:40 AM
Talk about bumping an old thread!

The blower is doing this at all RPM ranges right now. I'm thinking of giving the carb a good dunking in a bucket of Berryman's and seeing if that cleans things up. Not only is the stumbling annoying, it smells bad. I need a good breeze when I snowblow. :rolleyes:

SLR
12-22-2008, 02:57 PM
Is that your '84-87 200X in your avatar Glenn J?

Restrorob
12-22-2008, 07:22 PM
Boy you did dig up a old one !!!

You can try the soak and if that doesn't work do as I posted YEARS ago.....LOL

Two Seasons
12-22-2008, 08:05 PM
Sounds like the L-Head engine you have there. To me, it doesn't sound like anything other than it may need a little more choke to smooth it out.

I have two Ariens with the L-Head and they are cold blooded beasts. Hard to break them though.

Ever since new, both tend to surge at mid-range until they get a good heat soak. What I've done, and this doesn't seem to eat any more fuel (I get about 2hrs per gallon, is set the choke to either mid-range or a little more to the right (rich) and the surging will stop.

These engines tend to wick in the moisture too, as you will see your dipstick foam up after a hearty run with it. I change my oil every month during the winter season, then put away with fresh oil and a little oil fogging in the cylinder. I run synthetic oil in both. L-Head is noisy compared with the OHV engines out now, but they will take a beating and come back for more, year after year. Oldest one we have is a 1996 model. Just used it again today for 7hrs straight! I put between 100-125 hrs per season on each L-Head.

Glenn J
12-23-2008, 10:35 AM
SLR: That's my old 1985 200X. It had a white front fender on it, which almost made it look like an 86 or 87. I sold it and bought a 2003 Wolverine...which is what a currently have.

Rob,
LOL! I'm getting smarter as I get older. If a soak doesn't work, I'm going directly to the new carb route. No if's and's or but's about it!

Two Seasons,
I'd wager this one is from the mid/late 1980's. I'll have to take a pic. I agree that it is a cold blooded engine. When it was running smooth, I'd always let it warm up for a bit...even make a pass with the choke on one click before it smoothed out and ran fine without the choke.

But now I can't get it to run at all without stumbling. It's even stumbling a bit when it's under load. It's really bad when it's not under load. It practically stalls if you don't have the throttle set to full tilt.

Two Seasons
12-23-2008, 01:06 PM
SLR: That's my old 1985 200X. It had a white front fender on it, which almost made it look like an 86 or 87. I sold it and bought a 2003 Wolverine...which is what a currently have.

Rob,
LOL! I'm getting smarter as I get older. If a soak doesn't work, I'm going directly to the new carb route. No if's and's or but's about it!

Two Seasons,
I'd wager this one is from the mid/late 1980's. I'll have to take a pic. I agree that it is a cold blooded engine. When it was running smooth, I'd always let it warm up for a bit...even make a pass with the choke on one click before it smoothed out and ran fine without the choke.

But now I can't get it to run at all without stumbling. It's even stumbling a bit when it's under load. It's really bad when it's not under load. It practically stalls if you don't have the throttle set to full tilt.

There is your problem. After you adjusted the carb, your settings are not correct. Follow RestroRob's advise or take it to the dealer and let them do it. Most of us shadetree mechanics think we can do about anything, but the truth is the professionals do this stuff every day, not once every 5 years or so. If you have any doubts, take it to the dealer.

SLR
12-24-2008, 02:02 AM
SLR: That's my old 1985 200X. It had a white front fender on it, which almost made it look like an 86 or 87.

I loved those old Hondy's,Nothing would stop them,only issue i had back then was that blasted forward kicking shin busters when starting it.

Glenn J
12-24-2008, 10:01 AM
TwoSeason,
Yeah, the adjustment is certainly finiky. But the last time I took the bowl off, there was a sum crud in there. I should really add a fuel filter to it. I'm also thinking this gas with ethanol in it may be part of the problem.

SLR,
You're right! The kicking was a PITA! For a smaller 4 stroke, they were a bear to start. That was my biggest grip with that machine. Electric start on my current machine is awesome. I love pressing a button!

Glenn J
12-29-2008, 08:32 AM
I did the soak this weekend an no dice. I inspected the carb and all appears well. I have to say, this carb makes more "sense" to me than the other tank mounted briggs carbs I've work on. This one is more like an ATV/Motorcycle carb.

With regards to that adjustment screw on the bottom of the fuel bowl...is there a "starting" place for that? For example, on a few ATV carbs I've rebuilt, the manual will tell you to turn the pilot screw all the way in, then back it out 2.5 turns. From there you make your adjustments to get it to idle smoothly. Anything like that for the bowl screw? How about that screw on the side of the carb?

I was going to bring this to the dealer later this week, but they're now calling for snow. LOL!

Restrorob
12-29-2008, 09:05 AM
1 1/2 turns on the low speed (side) and 2 turns on the high speed (bottom).....Take it to a dealer and they will most likely put a new carb on......

Glenn J
12-29-2008, 09:16 AM
Thanks Rob! I'll give that a shot this week and see what happens. If that doesn't work, maybe I'll go the new carb route. If that's all they're going to do, I might as well save myself having to trailer it over, pick it up...and pay them for something I could do myself. :dizzy:

RidGFieLdPoWERMeChanIx
12-30-2008, 06:59 PM
Let me start out saying that i hate tecumseh carbs even the one's on the new units suck no matter what is done they will surg a little. but with the older carbs i never work on one with out putting a carb kit in it and the big thing that people dont do when they rebuild carbs are the welsh plugs b/c there cant get them out there one just above the low speed adjustment and one under the float i use a small punch that i ground a flat sharp edge on just hammer it into the center of the welsh plug and pry it off and the new plug go's in the hole and hit it in the center with a 1/4 extension to seat it. the one above the low speed is the on that must be removed and CLEANED we use a ultrasonic bath take great care removeing the old plugs the plug holes are not deep and if you go to far you can destroy the carb. i hope this help any other thing that i can help with just let me know.... DEANO

Restrorob
12-30-2008, 08:48 PM
Deno,

The biggest problem with Tecumseh carbs is the one passage that can not be gotten to for cleaning, I have soaked a couple of these carbs for as long as two WEEKS in NAPA cleaner. I have tried to cut the ball out of the end to gain access to this passage but it's not a ball but a pin, By the time you get this pin out the carb is damaged past being able to be reassembled.

Once this passage gets restricted the carb will cause the engine to hunt.

At a shop labor rate of $50/$75 a hour plus the cost of a kit, One is better off spending the $65/$75 on a new carb and KNOW that carb will run that engine properly. If a shop rebuilds that carb and it still hunts due to that one restricted passage they lost the labor time to rebuild and the price of the kit.

"Here" is the passage I'm referring to and is on most Tecumseh carbs with the exception of the plastic bowl carbs.


http://i107.photobucket.com/albums/m314/Restrorob/Tecumseh/TecuCarbNonCleanablePort.jpg

salvagedrover
01-02-2009, 07:31 AM
I am f'ing shocked!!! I agree w/ resthome rob on something! I would simply replace the carb. its probably easiest for you and the best investment. keep the old one for parts like the butterfly or bowl, things like that, but that's all, no jets, butterfly shaft, anything like that. I can get those tecumseh snow thrower engines running correctly every timeand 9 out of 10 of those times, its a new carb that does it.

Glenn J
01-05-2009, 11:05 AM
I think I'm just going to get a new carb. That pic Rob posted helped quite a bit, I saw that exact spot he pointed out in the pic.

Here's the number I pulled off the engine: HM80 144331N Any idea what the part number is for the carb? Is this a ready to install carb...or do I have to swap some parts over from the old, to the new?

Thanks in advance!

Restrorob
01-05-2009, 01:16 PM
It's plug-n-play right out of the box;

http://search.cartserver.com/search/search.cgi?cartid=a-8671&category=Tecumseh_Parts&maxhits=20&keywords=632334A&go=GO%21

Glenn J
01-05-2009, 02:10 PM
Sweet! Thanks Rob! More snow on the way...I gotta order this thing! My snowblower still runs...but it certainly sputters a lot. I used it again on Wednesday.