2185 muffler getting cherry red
 

Hi all, my 2185's muffler has been getting cherry red lately right around the inlet. I did find a hole, where the center muffler bolt has broken off and am assuming that's the cause. But I'm also suspecting that because the muffler has been getting so red that it's also the cause of the stud breaking. It's been doing this on and off for a few weeks now.

I've recently replaced the intake gaskets, and the coils (tapped to factory specs), and also the carb ( was chasing the bad intake gaskets). From the look of the plugs, it's running a tad lean. What could I possibly do to remedy this. It runs fine while under normal operation and while mowing. So I'm not sure why this is happening (other than the hole in the muffler currently.)

And also, other than spending 300 dollars on a new muffler... Has anyone replaced it with another type of muffler with success (I.e the cylindrical style muffler)?

Running lean is exactly what would cause this. Running on the slightly rich side is better for these engines than lean.

Looking at your last few threads, looks like that engine is probably done for. You had a bolt break in the valve cover too. Too much heat. Running lean, way lean for a while, like Couperino stated.

Honestly. The engine has good compression, I fixed the broken bolt and have no oil leaks. I'm just stumped on how to make it run less lean with no carb adjustments. I may tinker around with throwing the stock carb back on there and seeing if it's any better.

Ok, so with new Intake gaskets, (intake torqued to spec) new coils gapped to spec, new plugs, also gapped to spec. What the hell could I do to make the thing run slightly more rich? I mean, it's got 150-155 psi on each cylinder, and other than running lean, it runs fantastic.

Have you cleaned the carb?

I cleaned the old factory carb when I was chasing the dead cylinder issue. And decided to buy a china carb as well for testing purposes because I thought the old carb was bad. So it's a brand new carb on there with the old one cleaned and sitting in a box.

I never took the china carb off after I figured out that the intake bolt was loose causing my dead cylinder issue. That's also when I replaced the intake gaskets.

This may be a stupid idea, but could the throttle linkage springs being weak cause any issue? I mean, I don't necessarily see how it could... But then again. I could be very wrong lol

When I throttle up, it takes like a good 1/4 throttle before the mower will idle up.

You did not put a BRAND new carb on it, you put a no name chiseum carb on it and it is jetted lean obviously, or it would not show lean on the plugs and lean by running red hot on the muffler.
(get the muffler hole fixed) as that will cause the muffler to glow red also as oxygen is induced in to the muffler.
(it can also cause a backfire in the muffler on throttle down.)
But not to worry, soon it will blow a hole in the piston(s) and problem solved.
Either change the main jet to a step richer if it is not adjustable, or put the factory carb back on it.
Your engine will thank you.
Just my opinion. :bigthink:

I'm on board with this. And I know it's a china carb lol. That's why I said it that way and was wondering if maybe that could be the issue.

Now, the factory carb isn't adjustable. So how could I change the main jet a step richer?

I've also already fixed the muffler once. And I doubt at this point I have much material to work with. I do not want to spend the 300 that a new one costs so I'll look for a good used one.

My next question is... I've found a 20 horse from a 2544 (same year) . I know the ch18s manual says it's the manual for the ch18s-25s.... Would a swap be a simple thing/worth my time if I could snag it for cheap? Guys asking 80 bucks for the whole mower. Not sure if it runs or not, waiting on his reply. Obviously this would only be a possibility if the mower ran.