21 HP B&S Black smoke from muffler, possible Carb adjustment?

[wgmarti]

Thank you Sir. I need to order the carb kit and follow your directions for a rebuild. Most likley wont get to it until next week got a lot going on for the rest of the week. I appreciate your detailed instructions and the time you took out of your day. I''ll be sure to follow up once complete.

 

[wgmarti]

Finally got to work on the lawn tractor today. Rebuilt and cleaned the carb per guidance, adjusted the valves and put the new head gasket on. Ran it for about 10 minutes and so far no black smoke (little puff only on start up). Figured I would check the plug and it was burning normal no black carbon at all after 10 minutes. BUT while pulling the boot off the plug, to get the plug out the metal connector on the spark plug wire pulled off the wire and was stuck on the plug. How do I fix this? Do you bend the wires back against the insulation then clamp the metal piece around it?

 

[wgmarti]

Re: Update 21 HP B&S Black smoke from muffler, possible Carb adjustment?

Update. Finally got it running right for 3 weeks now. Ended up taking the carb off soaking and rebuilding it and draining the old gas. Also readjusted the lifters (slightly out of specs) and put a head gasket on it (although there was nothing wrong with it). I feel rebuilding the carb did the trick. Special thanks to Rivets for the instructions and suggestions. Thanks again for saving me a few bucks.

 

[Lizardskeep]

I need the torq. specs for the head bolts on this engine if anyone has them.

Model 331877
Type 2371G5

 

[Rivets]

Should be able to find everything you need in this manual.

https://docs.google.com/open?id=0B6NaqjIxWV1ybEN0LWo3azl6OUU

 

[SeniorCitizen]

I have one of those engines on my JD and it's the worst engine I ever owned. No black exhaust visible, sometimes blue at start up, but the plugs have been black from the beginning since shortly after the tractor was new. The strange thing is it drinks gas, but even after it is warmed, after being off for 30 minutes it has to be choked to start.

 

[Lizardskeep]

Thanks a bunch for the link. It helped a lot with the torque and a few other things I had questions on.

 

[Lizardskeep]

I have one of those engines on my JD and it's the worst engine I ever owned. No black exhaust visible, sometimes blue at start up, but the plugs have been black from the beginning since shortly after the tractor was new. The strange thing is it drinks gas, but even after it is warmed, after being off for 30 minutes it has to be choked to start.

My problem was a blown head gasket that was making the engine burn oil and puff out white smoke. I've been told this is a common problem with this engine.

This engine is on a Craftsman riding lawnmower and does really well on gas and usually doesn't need to be choked at all, except in the winter. Along with cutting grass it has to pull "mule" duty all year long too.

I believe that a little puff of black/blue smoke at start up, shut down, and engaging the load is normal for OHV engines, this one does it, but don't take my word for that.