Tecumseh won't run past half throttle

[Roadrunner123]

I'm not sure how that link helps It did identify the numbers on my carb as being 631400 with a number 272 on it but now I'm not sure what to do with this?
Here is a link to my carb without the diaphragm on. The welsh plug is still off and the hole is where the little metering ball is. As you can see it can't be removed.
https://photos.app.goo.gl/bCyxigHTfkeYpxCm6
https://photos.app.goo.gl/72fEXsCFmtiWsjfx9

[Arkie]

Question:

In the 2nd picture are the idle intermediate and air bleed orifices under that welch plug on the side of that carb and if so it appears that would have them orifices located on the side of the carb throat inside by the throttle butterfly? Two of them orifices have to be open for the transition to High speed and if blocked the H jet would have no affect.

If them 3 orifices access channels are under that welch plug did you remove that staked welch plug and clean/check them?

That carb does not look near as clean externally as the engine. Looks like maybe it's been under salt water for a long time or the snow blower has been used blowing salted snow and not cleaned off good after use.

[Roadrunner123]

Yes that is a new welsh. I'm sure how many times I can spray carb cleaner and blow out the holes. I've also run it through the ultrasonic twice. The carb is as nice as the engine. Its the new hd camera that makes it look like that. The other side where the paint is looks like new. Heck the auger has most of the original paint, I don't think this machine has had much use. It was on display in a huge Ariens dealer's showroom.
What I need now is to find the number of bowl carb that was used on a similar engine. What's confusing to me how to put a bowl carb on this machine unless its desgined for the same hp. Case in point, I turned my 75 hp outboard into a 90 hp by changing the carbs. The diffenece in the 3 carbs were air restrictors in the throats and the main jets were smaller on the 75.
If you go onto an Ariens forum they talk about this engine all the time as 2.7 hp (which is what the sticker says on my engine) but on tecumseh sites and the manual it call this a 3.5 hp. I have never gotten an answer for why is says 2.7 hp vs 3.5.

[bgsengine]

Yes that is a new welsh. I'm sure how many times I can spray carb cleaner and blow out the holes. I've also run it through the ultrasonic twice. The carb is as nice as the engine. Its the new hd camera that makes it look like that. The other side where the paint is looks like new. Heck the auger has most of the original paint, I don't think this machine has had much use. It was on display in a huge Ariens dealer's showroom.
What I need now is to find the number of bowl carb that was used on a similar engine. What's confusing to me how to put a bowl carb on this machine unless its desgined for the same hp. Case in point, I turned my 75 hp outboard into a 90 hp by changing the carbs. The diffenece in the 3 carbs were air restrictors in the throats and the main jets were smaller on the 75.
If you go onto an Ariens forum they talk about this engine all the time as 2.7 hp (which is what the sticker says on my engine) but on tecumseh sites and the manual it call this a 3.5 hp. I have never gotten an answer for why is says 2.7 hp vs 3.5.

HP can change based on how fast the engine runs, among other things - That is part of the reason behind the lawsuit long ago that caused manufacturers to start rating engines by Gross Torque - Because due to CPSC requirements (blade tip speed) engines had to be "throttled back" and thus produced less than the sticker HP.

Just get a carb for a 3.5 or 4 HP Tecumseh H35 or H40 (or HS40, or HS35 or HH35, etc) from the picture, that's a pretty common throttle lever - your main difference in a new float carb likely will be the choke lever configuration (but if you get one with manual choke, the lever can be bent to the needed shape if you have to)

This one for example - https://www.amazon.com/dp/B094MV76YT/re ... s9dHJ1ZQ== should be a drop-in fit , you may need to bend or re-configure the choke lever in some way to fit the snowblower, but the fuel fitting is straight in like your diaphragm carb, and the throttle lever is about the same configuration, so it should fit right in and not need to modify the throttle link at all - just take a couple measurements on your old carb and/or your intake tube to be sure it'll bolt up, and that float carb (which is fully adjustable) should do the trick, and at 16 bucks a pop, I'd get two , if the first one works, you got a spare.

[Roadrunner123]

thanks bgsengine, for the link. The measurements were good but the darn choke lever wouldn't work not because it's bent down but because it goes off to the side which would be outside of my shroud. I will keep looking. I still need to clean the carb one more time, seal the welsh and reinstall. I will update.

[bgsengine]

thanks bgsengine, for the link. The measurements were good but the darn choke lever wouldn't work not because it's bent down but because it goes off to the side which would be outside of my shroud. I will keep looking. I still need to clean the carb one more time, seal the welsh and reinstall. I will update.

but be sure to compare apples to apples - choke lever position when choke is open , or closed, on both , also, choke lever like that, being fairly soft metal (stamped steel) can also be bent sideways a bit.. and lastly, may also be possible to swap out with your old choke lever (assuming choke shafts are same sized, or close enough) also note the "spring" that provides friction to choke detents, actually threads in /out much like a screw (Though almost never comes OUT in condition to be re-used again, but it IS a replaceable part) But as I noted, just run a search on Amazon or eBay for Tecumseh H35 carburetor, and odds are good you'd find a suitable replacement for cheap.

[Arkie]

AND
You might think about going over to the m&d site and looking at some H25 to H40 or other H35 engines (find the Tecumseh list that is about 3 ft long and scroll to each side of your model) and get a part number from another engine that is a float carb and check the part number of the intake gasket for that carb and see if it's the same as yours for the bolt on dimensions and then do a on-line search.

Also when you see a carb on Amazon for instance if you will look close at the fine print sometimes you can see the SELLER listed and then if you cannot contact them through Amazon before purchasing about dimensions do a browser search on-line for their store and do the asking and they will usually answer if in the USA.
If you have Amazon Prime and get a wrong part you have the option to return FREE with a FULL refund.
Several of the clone carbs on flea bay have the mounting mm dimensions listed.

Using Tecumseh part numbers for carbs, gaskets, etc will still come up online for browser searches and on flea bay if available as OEM NOS or clone.

About the linkage wires. I take construction tie wire (concrete rod tie wire or baling wire) because it's easier to bend and make the linkages then after all is working ok I use that softer wire as a pattern and use throttle or choke wire or survey flag wire for the stiffer wire linkages.
You also will find that different type chokes were used due to the different breather mounting and you may have to mod the carb breather mounting with an adapter to the carb.

If you can find any fully adjustable carb that will bolt on to your manifold at first just to see if it will run GOOD.
You will find that Tecumseh used different types and sizes on intake manifolds at the carb mounting and some of the carbs just bolted straight to the engine with no manifold and they used a pulse fuel pump or externally mounted gravity fed gas tank for those.

If you get to the strike out stage sometime later:
If you will post up the mounting dimensions of your carb and show a picture of the breather side of the carb with the breather mounting hole dimensions, I think maybe I have some old float type small engine 3.5-6hp Tecumseh carb bodies in a box and if I see a dimension match maybe I can get a Tecumseh number off of the carb body for a clone replacement search.

[Arkie]

One example on flea bay at this link.

https://www.ebay.com/itm/253374294776?_ ... BM3IqVwvdf

[Roadrunner123]

Here is a picture of my carb without the diaphragm on the bottom.
https://photos.app.goo.gl/v7wvdx7CKdqrj3Qe6

[Arkie]

Here is a picture of my carb without the diaphragm on the bottom.
https://photos.app.goo.gl/v7wvdx7CKdqrj3Qe6

I seen one of my buckets of small engine carbs today and
I will need the center to center spacing of the throttle side bolt holes on your carb and the throat bore size on both ends and the center to center of the machine screw holes on the breather end, so as to see if any of these float carbs that I have is same. If any of mine are same measurements I can then maybe pull up a Tecumseh casting stamped part number and see if a clone is available doing the part number search.
I also have some H-35's in use with carbs mounted that look like yours visually, but the carbs on them are dirty so hopefully I will not have to try to get numbers off of them.

Your measurements can be mm or inches or both. (try to be within 1/16 inch in your measurements One of my old H 35 carbs body has a drop manifold bolted on like yours and it looks like your carb per the choke lever, etc. but close is no cigar when doing a sub. I can faintly see some numbers stamped onto it's body.