B&S Intek 900 carb rebuild - no welch plugs???

[mooch91]

All,

Yesterday I picked up a used rental Bluebird aerator with the B&S Intek 900 engine on it (122000 series).

It runs very well, though it surges at idle unless 1/4 - 1/2 choked.

I broke down the carb, cleaned it thoroughly. It's spotless now, in and out.

Upon tearing it down the second time, I realized something interesting - I saw no welch plugs inside the carb.

Are there not supposed to be two welch plugs covering the two round cavities? Is it possible this model carb has no welch plugs? Would the motor even be running this well without the welch plugs?

I also noticed what looks like no replaceable seat on the needle/seat assembly. Based upon the documentation I've been able to find, it doesn't look like there is a replaceable seat (the needle has a rubberized end on it).

Advice appreciated.

Thanks!

 

[reynoldston]

You are comparing this carburetor to a Tecumseh carburetor, different carb.

 

[mooch91]

You are comparing this carburetor to a Tecumseh carburetor, different carb.

The 797634 rebuild kit for this carb (carb number is 591299) comes with a series of welch plugs and the parts PDF for the engine shows them in the rebuild kit. Of course, the documentation does say "parts shown may not be included in all kits". I have seen similar B&S carb pictures online with them, though no guarantee that they are all the same...

 

[Rivets]

I'll bet if you did a little more info searching you would find that the seat for that carb is replaceable. Second, before you put the carb back together, did you check the float height? It needs to be set slightly rich (meaning the edge of the float opposite the pin should be slightly lower) to eliminate surging. As reynoldston said, you are comparing apples and oranges.

 

[mooch91]

I'll bet if you did a little more info searching you would find that the seat for that carb is replaceable. Second, before you put the carb back together, did you check the float height? It needs to be set slightly rich (meaning the edge of the float opposite the pin should be slightly lower) to eliminate surging. As reynoldston said, you are comparing apples and oranges.

Are you aware of any specific instructions for this rebuild? I have found nothing talking about float height adjustment. Considering the float itself is plastic, I'm not sure how one would make an adjustment.
Thanks.

 

[mooch91]

Attached is a picture of the rebuild kit for this carb:

My needle is like the one in the center, with the little rubberized tip.

 

[Rivets]

Two ways I have adjusted the float height on that carb are: one tapping the seat down into the carb body and two using a heat gun slightly bending the tang on the float. Unless you understand and except the responsibility that even a minor screw up can cost you a new carb, I would not attempt either. Both take a steady hand and fine touch, plus an understanding of what needs to be accomplished and what can go wrong. This is not for the faint of heart and could get very expensive.

 

[mooch91]

Two ways I have adjusted the float height on that carb are: one tapping the seat down into the carb body and two using a heat gun slightly bending the tang on the float. Unless you understand and except the responsibility that even a minor screw up can cost you a new carb, I would not attempt either. Both take a steady hand and fine touch, plus an understanding of what needs to be accomplished and what can go wrong. This is not for the faint of heart and could get very expensive.

The needle hangs off of a thin wire frame. I don't think I will attempt.

Still not entirely sure it's the float, but I priced a rebuild kit at $24 and a new carb at $54. I might just spring for the new carb and call it done.

Disappointed I can't just clean this one up. This will be the first one that beat me.

 

[mooch91]

Third time was a charm. I soaked and blew through all the passages again. Also re-gapped spark plug to 0.030 (it was at 0.040 or better). Surged for about 3 seconds and smoothed out. Happy now!