My exhaust is glowing on my lawn tractor

Hicksie

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BlazNT

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I am almost certain you need a new muffler. Looks as though it is broken and clogged.
 

reynoldston

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I am almost certain you need a new muffler. Looks as though it is broken and clogged.

Its really something that I can't figure out. Yes it dose look like the muffler is broken. I have had clogged mufflers come into my shop but then they lose high speed and run bad. I was thinking more like maybe running rich? or maybe a partly clogged muffler. This is one of then reasons its hard to trouble shoot on a forum and we are only guessing. :thumbsup: I was waiting for some ideas before I posted and I am not disagreeing with your post.
 

ILENGINE

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A mildly glowing muffler is not unusual and is present on most newer mowers, but is only visible in low light conditions. Your muffler appears to be too hot. I suspect your issue has to do with the ill running surging misfire that is dumping raw fuel into the muffler making is run hotter than normal.

May need to check flywheel key for being offset, make sure carb is clean, and check valve clearance. Could also be a leaking valve, so may need a cylinder leakdown test to determine. Also replace the spark plug. It sounds like you have a misfiring issue.
 

bertsmobile1

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Back in the adjustable main jet days a muffler like that was 99% a too rich mixture sending unburned fuel down into the muffler which combined with the air and continued to burn.
Now days we have fixed jetting so it is not quite so common.
Modern EPA regulations dictate a more complete burn within the engine and this is done by setting the carb at the leanest possible settings , way too lean for prolonged life of the engine and maximum power output.
Regulations specify what comes out of the exhaust as a percentage of the gasses so a trick used is to fit the mufflers loose which allows some air to be sucked into the exhaust both keeping it cooler and diluting the gasses coming out the other end so they comply with emmission regulations.
Add to this modern fuel burns hotter and headder pipes are generally way too short so the exhaust cops a beating and glows red hot around the input end.

Mufflers do three things, they slow down the speed of the exhaust gasses, they cool the exhaust gasses & they break up the wave fronts of the power pulses all of which reduce the noise levels.

For yours to be glowing red hot all over either the gasses coming in to the muffler are too hot, they are being held in there for too long or they are burning inside the muffler.
Or combinations of the above and here is where it gets tricky.
If the main jet is obstructed or the carb is leaking air then the mix will be too lean thus burn too hot in the cylinder thus be too hot when it hits the exhaust.
Obversley if the main jet is too big ( careless cleaning with a hard object ) or air intake is restricted ( filters dirty ) the charge will not have burned completely so will continue to burn in the exhaust making it too hot.
Or if the timing key has cracked and the ignition takes place a little too late then the charge will still be burning when it enters the muffler so will make it glow red hot.
Once the muffler gets really red, it will start to burn itself, making the metal thinner and that will make the ehaust glow even hotter in a self feeding loop.

So start with the basics, pull the flywheel and replace the flywheel key = timing correct
While the cover is off, clean the cooling fins and in particular the region around the head.
Fit a nice new air cleaner & prefilter
Check the carb manifold for air leaks by sprayng around the carb, including the choke & throttle pivots with WD 40 or similar, FROM A TRIGGER PACK NOT A SPRAY CAN (yes I was shouting )
Remove the float bowl and clean both the main jet & emulsion tube
Check the spark plug gap ( too big retards the spark just a little )
Check the valve lash

Or to put it another way do a full & proper service on the engine.
And yes you muffler will be toast so changing that is not a bad idea either.
If the condition persists then the only other things that can cause the over hot muffler is the govenor allowing the engine to over rev , the cam being out a tooth or on engines with more than 1 cylinder a burned exhaust valve allowing unburned fuel into the exhaist system.
 
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