New to the forum and really need help. 1998 seadoo GTS backfiring

Note: This site contains eBay affiliate links for which may be compensated
Not open for further replies.


New Member
So I bought a couple of seadoos 2 yrs. ago. Last summer my mother (crazy) in law wanted me to leave them at the cabin to play on, stupid me I did. The next day they brought them home to me and told me, " I got to the middle of the lake and it flipped over on me, I couldn't get it flipped back over so i told Garrett (my son) to bring a rope and the other ski. I tied it on to the ski and pulled it back UPSIDE DOWN".when I got it back I done the drain technique and got it running and ran it for awhile in my yard. I would let it get hot then shut it down for awhile then do it again till all the water was out. Every since then it hasn't ran like it did. The first few times out it ran just ok. Then a couple of weeks ago it really started bogging down and I heard a back fire. I figured I got some bad gas so I just went out and ran it, didn't do any good. I was working on it today, changing plugs, lubing it and cleaning the flame arrestor on it. After I got done with that I started it up and it was really backfiring and sputtering. It back fired so bad it blew the exhaust apart from the other connection. Please help, I'm really stuck and would like to get them back out on the water. Sorry for the long story. Just thought you would get a laugh out of it or need the whole story for a proper diagnosis? When I start and idle it, it does fine. When I give it gas is when it backfires.
Last edited by a moderator:
There are a bunch of threads out here regarding carbs and fuel lines. You will probably get some other good hints here from the experts.

My additional thought is that you may have ingested water into the electrical/electronics and I would recommend removing the mag cover and covers to the electronics, take the seat off and let it sit out in the sun for a day or two to insure there is no residual moisture. Hair dryer might accelerate the process.

I do not know if bad contact to the spark plugs would cause this, but it does not hurt to remove the spark plug boot and trim back the plug wire about 1/4 inch as suggested numerous places here. New plugs can never hurt.

Not open for further replies.