vertical exhaust pipe fumes

[marshall]

I'm finding that an hour or two on the tractor with heavy exhaust fumes in face is really foul. Sometimes my eyes burn and I get a headache from it and I always come in stinking and need to shower and change clothes. Not looking for a catalytic converter or major modifications but has anyone got an idea about improving what comes out of the vertical stack on a 50 cub? It seems worse since I replaced plugs, points and coil (which makes it run WAY better than it used to).

[Dale Finch]

Install an underslung exhaust!

[radioguy41]

Does it have a rain flap? Is it turned to the left rather than front or back?

[Scrivet]

First question is what do you have now? Just a short pipe? Pipe and muffler?

If whatever combination you have is not exiting over your head then you're driving right into it as you move forward.

[jsfarmall]

Your carburetor could be a little rich. More fuel equals more exhaust. Not always but does help some. Taller muffler or taller pipe under the muffler. Can put an elbow on the end.

[KETCHAM]

Two things to do....Taller pipe or run it under the tractor....Or quit breathing!!!!

[john2189]

Two things to do....Taller pipe or run it under the tractor....Or quit breathing!!!!

.


That’s three things

[KETCHAM]

Third thing is not an good at all

[Don McCombs]

What plugs are you running and what is the gap set to?

[Crimson Tim]

Thinking outside the box: propane or CNG conversion?

[marshall]

Hmmm. I didn't have a gapper when I installed the plugs and gapped them to visually match the old ones. I used Autolite 3116. You think that could account for more smoke? Manual says 0.023-0.027. Is that right for these? Are you talking about the idle adjustment on the carb or some other? The pipe does go into a muffler and then back to pipe with a hinged cover over the top of the stack. The whole exhaust pipe unit is a loose where it goes into the engine and thus it can rotate to any position especially while vibrating as I drive around around mowing.

What's a little odd is when it needs a surge of power say if I'm driving up hill or hit thick grass and I give it a little more gas, it responds with a extra puff of smoke out the exhaust that really smells foul. Like something other than gas. Oil? I'll have to see what color it looks to be.

[marshall]

After some more investigation I see why the pipe is loose. Both pipe and exhaust manifold where it screws in are stripped. See photos attached.
Not sure what I'm gonna do about this. Replacing the manifold is expensive. I'd like to make this a cheap fix. I wonder if a new pipe might tap into the manifold with some good twisting. I also found the the muffler has a clamp that doesn't firm tighten it down onto the exhaust pipe. So that spins around too. As you can see I also need a new cover for the air intake. That got hooked up in some other trees and fell off into deep grass.

[Don McCombs]

You can clean up the threads in the manifold with a 1”NPT tap.

[Scrivet]

Regular black iron pipe, not galvanized. If you can't find a 1" tap and you have a pipe with threads at both ends you can cut one end off about four inches above the threads. Make it into a tap by cutting a couple slits across the threads and use a pipe wrench to screw it into the manifold working it back and forth with your favorite snake oil.

Muffler clamp may need a new bolt. Or you can make a shim out of an aluminum can to increase the diameter of the pipe.

As for the air cleaner, time to trim some limbs if they're knocking that off, especially if you're going to be working under them with a taller exhaust, or you won't have a taller exhaust long.

[Dale Finch]

Trust me, and this is from experience...you will NOT find that lost air cleaner cap until you purchase a new one!!!