YouCanDooIt
New Member
Just dropped another motor in my 97 GTX. Went to start, turned the engine over several times with choke to prime gas through the lines, and it started for a few seconds and stopped. I pulled the choke and hit the start button again, and BOOM!! Huge, loud ass backfire out the exhaust. When I say loud I mean shotgun blast X2, ears still ringing an hour later, wife running out of the house in a towel screaming "wtf was that" loud! Needles to say my butt hole was puckered, and my wife said I looked like a scared puppy when she ran out.
After calming down and having myself a cold one, I went outside to see exactly what went wrong. After looking the ski over a bit, I noticed my water box looked pregnant. The blast expanded out the side of the water box, and blew a hole in the exhaust hose, and pulled the hose right off the exhaust outlet!
The motor was from a ski with a burnt pto side piston, I put a fresh top end on the engine, and didn't touch the bottom end. The GTX was running at the end of last season, but the compression was low and the crank seals were leaking pretty bad. I do not think it is a timing issue, simply because I did not mess with anything in the bottom end of the motor, and as I said the gtx was not having any ignition or timing problems last season. I will say this, some how I forgot to fill the tank up when winterizing it, but I know i put stabil in the tank. Also the ski has been sitting in my garage up until about two months ago.
I am wondering if a critter climbed up into the water box and made a nest blocking it somehow? however, when the ski started up and ran for a few seconds, the normal blue smoke was coming from the exhaust outlet. Maybe bad gas or carbs filling the crankcase somehow? I don't really think bad fuel would cause such a strong backfire? I have a extra waterbox and hose lying around, but I am afraid I will destroy them too, so I want to make sure I have this figured out before I try starting it again. Any body have ideas on what could cause such a thing?
After calming down and having myself a cold one, I went outside to see exactly what went wrong. After looking the ski over a bit, I noticed my water box looked pregnant. The blast expanded out the side of the water box, and blew a hole in the exhaust hose, and pulled the hose right off the exhaust outlet!
The motor was from a ski with a burnt pto side piston, I put a fresh top end on the engine, and didn't touch the bottom end. The GTX was running at the end of last season, but the compression was low and the crank seals were leaking pretty bad. I do not think it is a timing issue, simply because I did not mess with anything in the bottom end of the motor, and as I said the gtx was not having any ignition or timing problems last season. I will say this, some how I forgot to fill the tank up when winterizing it, but I know i put stabil in the tank. Also the ski has been sitting in my garage up until about two months ago.
I am wondering if a critter climbed up into the water box and made a nest blocking it somehow? however, when the ski started up and ran for a few seconds, the normal blue smoke was coming from the exhaust outlet. Maybe bad gas or carbs filling the crankcase somehow? I don't really think bad fuel would cause such a strong backfire? I have a extra waterbox and hose lying around, but I am afraid I will destroy them too, so I want to make sure I have this figured out before I try starting it again. Any body have ideas on what could cause such a thing?
