View Full Version : Black smoke, clean plugs new EI

07-13-2005, 12:22 AM
1990 Tristar 220 - Just put new plugs, EI & Coil on motor. I am putting new wires on this weekend. Runs great, but at idle & startup it puffs out black smoke/fumes. I can get around 42K RPMs opened up, but at idle, it doesn't appear to be burning clean. Any suggestions? Any suggestions on fuel additives to make it burn cleaner? By the way, what octane fuel should this baby have in it?

Also, thanks to all you prop heads! - we are at the lake house this summer & if it weren't for you guys, my boat would be collecting dust at the dealership waiting on service instead of resting down at the dock after pulling my kids around the lake! You guys are awesome!

07-13-2005, 07:39 AM
Check the flame arrestor to see if it's clean and recheck the timing. Also, you should get closer to 5000 RPM(42K is 42,000) unless it's a big block.

07-13-2005, 11:27 AM
Ok I'm learning here - what and where is the flame arrestor? The guys at skidim told me that on the 351 ford 44,000 rpm was about max - does that sound right?
Thanks for your help!

07-13-2005, 11:29 AM
Looks like the air cleaner, but is used to prevent backfire sparks.

07-13-2005, 11:30 AM
THe flame arrestor is like the air cleaner on a car motor. on the top of the engine above your carburetor. Have you fiddled with the carburetor any since you added new ignition components? Did it smoke before adding those things?

07-13-2005, 11:35 AM
I broke an alternator belt a month ago - when it broke, the belt got chewed up into a million little pieces. The flame arrestor was coated solid black. I cleaned it with gasoline, but not with a brush. Would there be a problem with removing it just to see if that solves the problem? I haven't touched the carb but it is filthy, any good suggestions on cleaning it?

I'll check the timing - haven't done that.

07-13-2005, 07:13 PM
Gas is OK to clean with, but I use the carb cleaner sold by NAPA. A lot stronger and evaporates really fast so if it's hot and humid, don't be surprised to see frost on it when you clean it. If you have access to an air compressor, you can blow the arrestor out from the inside so the debris doesn't get driven deeper into the element. You can idle and rev the motor without the flame arrestor, but don't drive the boat anywhere with the motor box closed if the arrestor isn't in place and secure.

By the way, as I said before, the RPM is not 44,000, it would be 4400. I have seen them rev higher than 4400, but not very much higher.