Fire from exhaust

[mnmfors]

Today I got spark back to my 1977 Mercury 150. <br /><br />When it starts it shoots a flame out of the exhaust (my exhaust is ported 3" thru mid section). I only started it for a second or two, just to hear it run. <br /><br />I wonder if this is what I am to expect when running in the water? Seems kinda dangerous. <br /><br />I havent done my carb rebuild and link and syc yet. Maybe it is just the timing off or fuel buildup? Carbs are real bad, (spitting fuel)and I just changed the distributor (needs timed)

 

[12Footer]

Re: Fire from exhaust

It will do that if you cranked it for any length of time with the absence of ignition. all the unignited fuel is expelled into the exaust ports. The fuel still insdie the cylinders might also drain-down by gravity, into the leg.<br />Then, when you restore ignition, kaboom.<br />Cars do this too. It should quit in short order, If it does not, the carbs may be introducing solid fuel instead of air.fuel mixture,most often caused by choked carbs.