Carb question

#1
I just picked up this MTD and the carb had this rigged up plug on one side of the carb. Im not sure what it is. On the other side is where the fuel line is hooked up. Can anyone tell me if the carb is original to the engine or was it replaced or if this other plug is used for something else... Like a dual feed fuel system??? Thanks. 68936052_10216639599077442_8957401862017908736_n.jpg 68899620_10216639596757384_5645377169312972800_n.jpg 68588488_10216639428393175_7424021060430856192_n.jpg 69290010_10216639356191370_8359726878965104640_n.jpg
 

markus

Well-Known Member
#2
It is the atmospheric vent, run the tube into the hole of on the back of the air cleaner if you are going to use the carb as it needs to breath. It is not the original/correct carb for that engine, it is a non adjustable unit so it cannot be fine tuned. Those are mostly found on things that are fixed throttle type application, so it may not like to to run at certain speeds etc.. With that said though I bought a bike that somebody had put one on once (different version with a primer bulb built in) and much to my surprise it ran pretty well with it.

You would want to get a fully adjustable if you were going to replace the unit with a stock type carb in the future that is intended for 3.5hp application at the very least ( use your engine part numbers to look up your original carb number). Remember to block that hole off or replace the air cleaner backing plate as well though so there is not a big open hole bypassing your filter and going strait into the engine....as the proper type carb for you engine will not have type of vent on it.
 
#3
It is the atmospheric vent, run the tube into the hole of on the back of the air cleaner if you are going to use the carb as it needs to breath. It is not the original/correct carb for that engine, it is a non adjustable unit so it cannot be fine tuned. Those are mostly found on things that are fixed throttle type application, so it may not like to to run at certain speeds etc.. With that said though I bought a bike that somebody had put one on once (different version with a primer bulb built in) and much to my surprise it ran pretty well with it.

You would want to get a fully adjustable if you were going to replace the unit with a stock type carb in the future that is intended for 3.5hp application at the very least ( use your engine part numbers to look up your original carb number). Remember to block that hole off or replace the air cleaner backing plate as well though so there is not a big open hole bypassing your filter and going strait into the engine....as the proper type carb for you engine will not have type of vent on it.
It is the atmospheric vent, run the tube into the hole of on the back of the air cleaner if you are going to use the carb as it needs to breath. It is not the original/correct carb for that engine, it is a non adjustable unit so it cannot be fine tuned. Those are mostly found on things that are fixed throttle type application, so it may not like to to run at certain speeds etc.. With that said though I bought a bike that somebody had put one on once (different version with a primer bulb built in) and much to my surprise it ran pretty well with it.

You would want to get a fully adjustable if you were going to replace the unit with a stock type carb in the future that is intended for 3.5hp application at the very least ( use your engine part numbers to look up your original carb number). Remember to block that hole off or replace the air cleaner backing plate as well though so there is not a big open hole bypassing your filter and going strait into the engine....as the proper type carb for you engine will not have type of vent on it.
Would you happen to know the model number of the carb i need??? Thanks
 

markus

Well-Known Member
#4
Would you happen to know the model number of the carb i need??? Thanks

Not a clue, but like I had stated above, use your engines model number to look up the parts listing which will pull up the carb number. Most likely you will not find an OEM replacement anymore, but that number will usually cross or show on some of the low budget universal replacement carbs that come out of china (quality is bad, but if you cant get OEM you have to work with what you can get). They kind of whittled down to just a few different carbs in certain ranges of HP and design so they could cover more bases with less products, but usually you can find your number associatied with one that will be close in bore size, and have needles, some type of universal (bend to fit) chike lever and correct throttle shaft cnfiguration.
 
#5

markus

Well-Known Member
#6
Thanks @markus my model number is H35 - 45355H I think i found 2 carbs on line and would like your opinion. Im not opposed to paying up for one as long as its correct and or will work. Id even buy a used one if it can be rebuilt. Any thoughts or suggestions are appreciated. Youve been a big help already. thanks

https://www.jackssmallengines.com/jacks-parts-lookup/part/tecumseh/631795a

https://www.monsterscooterparts.com/carburetor-632615-632208-632589-tecumseh-h30-h35.html
The downside for the OEM replacment in your situation is they are incomplete (so they can fit a few different engine configurations). So it will come without the levers and fuel inlet. to do that correctly you would also need to order the parts you can't swap off your current carb. Thats not a big deal but of course the cost just keeps climbing from the $60-100 that those service/replacment carbs usually run from vendors.

The aftermarkets like the 2nd link you show of course come with the parts (bend the choke lever to fit your application), quality control is not there at all on those and they can be problematic as to the way they run sometimes. If going with one of those I suggest going through it before install. I have had them arrive with pinched gaskets, holes in the float, loose fuel inlet, cracked jet/bow gasket, etc.....and I have only bought about 4 or 5 of them in my time with these o_O Pull it down, test the float, grease the gaskets blow out any shavings/debris etc..

With both of those, I would suggest perusing ebay, both units can most likely be found at a cheaper cost that what both those vendors are showing. the aftermarkets you can usually find as cheap as 9-10 bucks but watch that its coming from a US vendor so you dont end up waiting for it from overseas. That version you show (aftermarket) is probably the better fit out of the box for you as it has a straight fuel inlet, since you have a remote tank bike.

I dug around but looks like I am pretty much cleaned out out on the H30/35 sized original carbs from what I see so I cant help there, I swear I had 3 or 4 spares....if I do I stashed them away really good cause I cant find them!
 

DaddyJohn

Well-Known Member
#8
The downside for the OEM replacment in your situation is they are incomplete (so they can fit a few different engine configurations). So it will come without the levers and fuel inlet. to do that correctly you would also need to order the parts you can't swap off your current carb. Thats not a big deal but of course the cost just keeps climbing from the $60-100 that those service/replacment carbs usually run from vendors.

The aftermarkets like the 2nd link you show of course come with the parts (bend the choke lever to fit your application), quality control is not there at all on those and they can be problematic as to the way they run sometimes. If going with one of those I suggest going through it before install. I have had them arrive with pinched gaskets, holes in the float, loose fuel inlet, cracked jet/bow gasket, etc.....and I have only bought about 4 or 5 of them in my time with these o_O Pull it down, test the float, grease the gaskets blow out any shavings/debris etc..

With both of those, I would suggest perusing ebay, both units can most likely be found at a cheaper cost that what both those vendors are showing. the aftermarkets you can usually find as cheap as 9-10 bucks but watch that its coming from a US vendor so you dont end up waiting for it from overseas!
I wholeheartedly agree with checking-out the eBay Tec carbs (I think they're identical to the Monster Scooter Parts offering in the link).
I've bought a few of these and have had good luck with them. For the low purchase price, there isn't much of a risk either.

Heck, once you find if one of these will do it for you, order a spare. ;)
 
#9
I’m running newer Tecumseh carbs out of the Czech Republic...one on an hm80 and one in a hs50....about $90 shipped....bolt and go....sle equipment
 
#10
I’m running newer Tecumseh carbs out of the Czech Republic...one on an hm80 and one in a hs50....about $90 shipped....bolt and go....sle equipment
SLE Equipment in Antioch Tennissee?
sleequipment.com?
We’ve been searching for a reliable supplier since the ROP shop hasn’t carried much carb inventory.
 
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