Puff of smoke from the engine

Started my bike up after letting it sit for 4 days. Choked it, hit the ignition and got a loud enough pop to startle me, and a puff of smoke from somewhere near the bottom front left of the engine, if you were sitting in the seat. Smelled gassy, didn't fire up, then I hit the ignition again and it fired right up.

It's pretty cold out, upper 30, low 40's been rained on a little also, any idea what the cause may have been?

 

Unburned Fuel gathering in the Collector Box that ignited when the Bike started.

If the Mixture is Rich it just Pops and smokes.

A Lean Mixture doing that can ignite with such force that it will cause a weak seam to separate and damage the Collector Box.

Looks like you are the lucky guy this time.

 

Is there something I need to do to keep it from happening again?

 

Do a tune-up and keep your Battery charged-up.

Don't keep cranking-over an engine that doesn't start right away.

If your Battery is charged-up good and the Plugs are not fouled ... investigate why the Bike isn't catching and starting right away.

Whenn the cooler weather descends upon us ... it's a test for how well tuned the engine is with regard to the Cold Start Circuit and the Pilot Mixtures.

There is also a chance that it means you have a Tight Valve. You should Measure your Valve Clearances to be sure that you don't have a Valve too tight that gases are escaping to the system past a Valve not fully closed and seated.

 

Gotcha, this puff of smoke happened on the initial crank, as soon as I tried to crank it up. The plugs have 1k miles on them by now, could probally use some new ones also.

 

How often you change Plugs depends on how well the engine is tuned. If you are so rich that the plugs are easily fowled ... you need to take corrective action to prevent that.

Otherwise, a well tuned engine is good for several thousand miles on a new set of plugs.

I change mine when I do Oil Changes. Usually, 25-hundred miles or something short of 3-Thousand Miles. I dispose of Plugs that are still "Good" but I'm doing a "Living-Tweak" reading the Plugs quite often looking for the Best Fine-tune I can put on a 750 Max.

I'd say ... right about now, she's where the most fun is!