small engine problem

[Armed4defense]

I have a Sears push mower - mainly use it to chop compost which has developed a problem I can't diagnose. It had a leak at the air filter which I finally stopped -after replacing the gasket behind the air filter housing, the primer bulb and the needle valve. So gas doesn't leak any more and I cleaned everything well on final assembly, but when I go to start it, it starts but air filter housing catches fire and have to put it out. WTH? Have not used starting fluid on it recently ( although I have in the past) Any thoughts would be appreciated!

 

[Diablos]

have you cleaned the carb? kinda sounds like a float issue

 

[Armed4defense]

have you cleaned the carb? kinda sounds like a float issue

Yes - I have been working on this for awhile. I'm stumped. That;s why I asked you guys

 

[Diablos]

then i'd re-check to make sure the needle is seating correctly and that float level is good

 

[Jp8819]

Was the float needle set back where it was originally? Also not popping back threw the carb is it? That could be a stuck valve or one not closing all the way.

 

[Scsmith42]

Sounds like it’s either too lean (and backfiring) or an intake valve is sticking.

 

[BrettB]

This could be an issue in which it is firing slightly out of time , if you are chopping mulch you could have hit a stick or something hard enough to partially shear the flywheel key. This could result in a timing issue because the flywheel (that has magnet for ignition coil) is now in a slightly different spot when it fires the plug - meaning the intake valve could still be open when combustion happens
Without looking at it , i cannot be sure but this is certainly a possibility based on how you are using it

 

[Armed4defense]

Going to check these possibilities - Thanks guys! When you don't know ask CFF!

 

[71Ragtop]

Anyjuan who has spent time fixing small four and two stroke engines is familiar with this warning light.

 

[nhusa]

The easiest fix is to either scrap the mower or get anew carb on eBay.

 

[Get Off My Lawn]

Brett brought up a good point. What brand motor does the mower have?
The Techumseh has a frail flywheel key.