View Full Version : Backfire

08-12-2007, 11:27 AM
I have a 91 maristar 210 454 that I just had the carburator rebuilt. It runs better, but two things I noticed.

1. When I start it on the trailer (in the water of course) it requires nearly full throttle for at least one to two minutes to keep it sputtering along before it will run smooth enough that I can put it in neutral and doesn't die.
2. When I am pulling a wakeboardeer/waterskier there are a few times it backfired when I went from Neutral to a good amount of throttle. This never happened before.

Are there some minor adjustments that can be made to clear a few of these issues up?

08-12-2007, 01:16 PM
Make sure it's not leaking gas when it's on that angle by removing the flame arrestor and looking into the carb. You don't need to run it for this and I would recommend NOT running it with the arrestor off, until you get the problem fixed. How were the idle screws set- on the motor or off?

08-13-2007, 01:41 AM
Backfire through the intake is a lean condition.
through the exhaust is rich, sounds like your carb still needs work or proper adjustment.

08-13-2007, 10:58 AM
If you had a backfire you might need a new powervalve also. Backfires ruin them.

08-13-2007, 06:40 PM
Where is the powervalve and what does it do?