Changed out a fuel filter last night on my 94 carb 22R. Could not believe what came out of the filter in terms of water and debris. Amazing fuel even flowed.

Went to start it this morning and it ran like crap. Thought it might be water so I ran it up to 2000 RPM for a minute or so. Let of the throttle and it died. All kinds of smoke out the exhaust (not white smoke as in blown HG). Smelled like unburned fuel so I looked under at the exhaust and saw the catalytic converter was red hot. Looks like fuel was loading up in the convert and burning. The timing is

Give me some suggestions on what to troubleshoot. Thinking it could be a choke stuck open, dumbing excess fuel in the barrels?

 

Catalytic converter could be clogged... I've heard them blow up and completely seperate from the rest of the exhaust system. If there was actually water in the fuel system, and the mixture and timing adjustments were both off, these all contribute to a very short life for your catalytic converter.

If it unbolts, try running the motor without one and see if it runs any better.

 

Will do. Thanks.

 

Could not get the cat off owing to rusted bolts. Have to borrow a grinder tomorrow.

Can't get the #$% thing to start now. Plenty of fuel in the barrels, but don't even get a burp when turning it over. Could a clogged catalytic converter totally prevent combustion? Silly question, I know, but have to ask.

 

Mine was clogged badly and it still started and ran fine at idle.
Once there was a load on the motor it ran like crap and didn't have ANY power.

 

a little off subject i had an old 4 cyl beemer that clogged a muffler and it wouldnt start at all backfired through the intake pulled the muffler off ran like a champ but loud as well u know.

 

and usually if your burning fuel in the cat it will smell like rotten eggs running an engine lean will do the same thing sure u didnt clog a line or the carb??

 

Could easily have clogged a line or jet in the carb, but woud think this would cause low or no fuel in the barrels. I did notice that the fuel line in the window was above the window. Had to rock it back and forth to see the level line. Guess I am going to have to pull the carb off as well. Just rebuilt it two weeks ago.

 

Never seen the inside of a catalytic converter. I understand it is high in surface area to maximize exhaust contact with the palladium surface. Is it a mesh or series of flat surfaces inside?

 

Ditto on XSLO/XCAB suggestions. Heard the same about not starting once also.

 

your not leaking fuel out the vaccuum ports on the carb ru?? i had the same problem with my 81 carbd 22r

 

I pulled the vacuum line off the aux accelerator and accelerator diaphrams and saw no fuel. Don't suspect broken diaphrams if that is what you are thinking.

 

hmmm id say float adjustment and cat but thats just an educated guess

 

THat would explain the high fluel level in the sight glass.

If the float level is set wrong, it will kick off the fuel inlet ;ate and alow an overflow of the bowl. Overflowing gasoline enters the intake as a liquid, and has not passed through the venturi. Therefore, you have the extremist of running rich.

THe spark plugs are probably too wet and too much unburnt gasoline probably got inside the cat, causing the cartoonish, exploding boiler effect.

Take all the plugs out, c;ean them, and crank the starter to blow all of the old gasoline. THen let the rest evaporte out for an hour. THen pop your cleaned plugs in and give it a shot.

 

Pulled the cat off and could see through it well enough. Not clogged. Pulled the carb off and disassembled it. Found water in the bowl and other areas. Cleaned it up and blew air through all jets, etc. and put her back on. Runs again! Thank