Disphragm Carb No Mixture screws

[ClipperBuggy]

I picked up a Tecumseh diaphragm carb with no mixture screws. Has anyone ever seen this set up before?
how could it not need adjustment?

What do I have?

 

[ClipperBuggy]

Part number 630884

 

[MB165]

post a photo, is there a primer nipple on the bottom? since there are no adjustments its a newer manufacture, "emissions" spec., maybe off a snowblower??

 

[lawn-boy biker]

Has anyone ever seen this set up before

I have at least 3 of them.

how could it not need adjustment?

The same can be said for the bowl carbs.

Thanx to the EPA.

 

[ClipperBuggy]

 

[ClipperBuggy]

You are absolutely right. I just found a Tecumseh manual notting fixed jet is "emissionized"

So what do you guys think about these types of set ups? am I going to have a hard time getting this thing to feed the correct amount of mixture? Am I putting my motor at any risk?

What is the draw back i am dealing with?

 

[lawn-boy biker]

I going to have a hard time getting this thing to feed the correct amount of mixture?

Possibly. Best to put it into service and see how it fares. Might be fine "as is".

Am I putting my motor at any risk?

Not even a little bit.

What is the draw back i am dealing with?

At worst it will be unusable which would bring you back to square 1.

 

[MB165]

it sure does look old, I don't think its gonna make a good minibike carb. There is no welch plug on the side, no fuel passages either..... I guess it has no idle circuit.....no idle speed screw either, its probably off a fixed speed engine. can you make out the 3 digit code stamped on it?

 

[ClipperBuggy]

it has stamped on it: 31 4311

 

[CarPlayLB]

I may have some diaphragm carbs with adjustment screws...PM me if you need one

 

[joshua. c.]

it sure does look old, I don't think its gonna make a good minibike carb. There is no welch plug on the side, no fuel passages either..... I guess it has no idle circuit.....no idle speed screw either, its probably off a fixed speed engine. can you make out the 3 digit code stamped on it?

no welch plug? then what is that big round thing on the side in the third pick? looks like one to me.

the fixed jet carbs are intentionally run lean for emissions so they don't run as good as the older adjustable carbs. its also I diaphragm carb so you'll need a new diaphragm every time you clean it but on the upside after you clean it there is no re tuning needed. Its not the greatest carb in the world, just get an adjustable float bowl carb and you'll be much happier.