SportJet 120.. Needs Help!

I have a 95 Bayliner Jazz with a Sport Jet 120. Last year she ran great. Plenty of power. Smooth out of the hole. Great. This year (with the same 2.5 poeple) It takes forever to get on plane and the top speed seems to have slowed significantly. I looked at the plugs. They do not look bad but, I will replace them today. Any other suggestions?<br /><br />SalManilla<br />rlewis@intrex.net

Re: SportJet 120.. Needs Help!

Welcome to iboats.<br /><br />Same boat, same year, same motor. Had a trade-in that acted the same. I put a timing light on it and most of the time it wasn't even firing on the scale. There is a magnet bonded in the center of the flywheel. Basically it's a refrigerator magnet. It's bent around in a circle and it developed cracks. The trigger signal is supposed to be where the two ends of the magnet meet. The sudden switch from North to South poles on the magnet is what is detected to trigger the spark. With cracks, there were multiple N/S joints, so the motor fired irratically. If you have a timing light, check this out. Don't be suprised to see the timing jump around a bit, but if it flashes off the scale I'd suspect you need a new flywheel.

Re: SportJet 120.. Needs Help!

Could Old Plugs and Wires Contribute to this? What about Gear Lube? I have only had the Boat for 1 Year. So, I do not know the history.<br /><br />SalManilla

Re: SportJet 120.. Needs Help!

Check for spark on all 4 cylinders. How old is the gas, when were carbs last rebuilt.<br /><br />Click on my homepage (icon above) to see ignition troubleshooting info for the Sport Jet.<br /><br />First I would change the plugs, then check for spark on all 4, if OK, then your carbs could need rebuilding.<br /><br />Also, on the jet drive, make sure the gate is opening fully. Inspect your wear ring for wear.<br /><br />I suggest a manual, find one here on iboats, or a used one on ebay. Seach for "sport jet".<br /><br />Ken