SH exhaust leak

My SH exhaust leaks just enough to spit sooty condensate on the
sheet metal. This is right at the junction of the new 2" manifold
pipe and the new muffler. I've got the clamp as tight as I think I
can without twisting something off.

Any suggestions on how to seal it up?

Motor is rebuilt and runs perfect. I only get a shot of black smoke
at start up. It does not otherwise smoke.

This is an intermittent issue depending on how much condensate
the weather creates. I keep it inside and the ceiling above is black.

Thanks in Advance

(quoted from post at 10:59:24 04/18/11) My SH exhaust leaks just enough to spit sooty condensate on the
sheet metal. This is right at the junction of the new 2" manifold
pipe and the new muffler. I've got the clamp as tight as I think I
can without twisting something off.

Any suggestions on how to seal it up?

Motor is rebuilt and runs perfect. I only get a shot of black smoke
at start up. It does not otherwise smoke.

This is an intermittent issue depending on how much condensate
the weather creates. I keep it inside and the ceiling above is black.

Thanks in Advance

Click to expand...

If the ceiling above where you park the tractor is black and sooty, the carburetor is set way too rich. Plain and simple. Are you using an original style muffler clamp, or an ordinary muffler clamp?

Dean - A puff of black and shot of sooty condensate in the exhaust is perfectly normal when cold-starting a carbureted gasoline tractor. My IHC's, Olivers and M-M all do it. So do also friends' Deere, M-H, Allis, etc. All our shops with low ceilings are spotted with hundreds of black "cold start" smudges.

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As for spitting condensate out the muffler joint, I've had success lightly buttering the outside of the manifold pipe with muffler cement before sliding the muffler on (stove cement works too - it's the same stuff). Clamp the muffer, then let the cement air dry for several hours before starting the engine.

Over time (usually a year or two) the cement will gradually break up and blow out and the spitting will return. But it's a simple matter to renew as required.

Ordinary/modern muffler clamp.

Will an "original" help? I now remember that the original is a flat
bar type rather than the round bolt type of the new style.

This carb came off of a good running 300 with the transmission
blown out below both bull gears. I disassemble ,cleaned, and
put back together and it runs great. It has no adjustment on the
bottom, only a plug. I read that this was the "full"power option.
Once the engine is warmed up it will not leave a black smudge
on the ceiling. The only other time it will blow black smoke is
momentarily when going from idle to WOT.

I don't think it's running too rich BUT how do I tell and what do
I do about it?

rustyfarmall

I'm of the opinion that the black smoke upon a cold startup is the result of too much fuel from choking to start!? and not a carb setting?

Have some patience with this amateur

You got it Dean!

However in order to start a cold engine with an updraft carburetor, a "blip" of the choke is usually required. This results in an excessive rich condition - and thus sooty exhaust - for the first few revolutions of the engine.

Leaning the carburetor will not change this. Rather it will make MORE choke necessary to start So you will still get a sooty puff of exhaust. Also leaning the carb will cause running problems (stumbling, loss of power) while running.

As long the engine starts easily and runs well once it's warmed up simply leave it alone. (Consider instead the momentary sooty exhaust a "feature"!)

(quoted from post at 18:58:09 04/18/11) Ordinary/modern muffler clamp.

Will an "original" help? I now remember that the original is a flat
bar type rather than the round bolt type of the new style.

This carb came off of a good running 300 with the transmission
blown out below both bull gears. I disassemble ,cleaned, and
put back together and it runs great. It has no adjustment on the
bottom, only a plug. I read that this was the "full"power option.
Once the engine is warmed up it will not leave a black smudge
on the ceiling. The only other time it will blow black smoke is
momentarily when going from idle to WOT.

I don't think it's running too rich BUT how do I tell and what do
I do about it?

Click to expand...

"Full power option"? That is a new one on me. If that carb were mine, I'd be finding the adjustable needle, packing nut, and packing gland and replace that plug. I've got 2 Hs that get started on a regular basis. Niether of them gives a puff of black soot at start-up.

What does the bottom needle do?

Sooty exhaust adds character as far as I'm concerned. I just don't like it staining my new paint. I've been pretty diligent about wiping it up but still have some staining.

Dean sounds like you have the 361525R91 carburetor. Put pete 23 in the search box then go to international IHC discussion board to where it says pete 23 carb info.4-2-11. I posted information about the carb. and picture. If it runs okay I would leave it be though. If the SH has 3-9/16 pistons installed you would be close to the same engine IH used the carb. on. Putting a high speed adjustment screw in that carb is not ideal. The main seat or jet may not be contoured for the screw tip.
Unless you can seal the joint its going to have moisture or unburned fuel run down. With the upright exhaust condensation and any unburned fuel at start up will find its way back down.
Short runs are worse, but even if started and worked hard some will happen before complete warm up.

I did put the 3 9/16th dome pistons in. Great power!! Sure is a different tractor after the new motor.