1996 DT40 Backfire Damage

[WhiteKnuckles]

Hello. Last year I purchased a 1997 Lund 1600 Rebel SS with a 1996 Suzuki DT40. Its been parked for a few months, so before taking it out this weekend, I was going to run it on the muffs. It didn't start the first few times, then started, backfired and stalled. After the backfire, I noticed fragments of what appears to be a thin black rubber membrane exit the exhaust. I'm curious to know what everybody's thoughts are as far as the source of the rubber fragments.

Additional information: The previous owner (original) didn't take it out much. Probably run less than 200 hours since new (he was a very big guy....like not quite 500 lbs big). Everything looks brand new when you take the top off. Water pump/impeller replaced when purchased. Consistently only starts about half of the time. Oil fouling on bottom plug only, with very light tan coloring on top plug. After the backfire/stall, there is no more electrical power at the motor. The choke does not move when the key is depressed, and there is no movement on the starter.

Before I start checking fuses and shooting wires, I kind of wanted to identify the source of the rubber fragments in the exhaust. I do intend to take it in for service at this point, but was hoping to have a better idea about what is going on before I bring it in. Your thoughts are very much appreciated. Please let me know if you want to know more.

[Solarman]

dt40, '97, backfire

When you say the rubber came out of the exhaust, do you mean the prop? Or the back of the mid section?
Can you see any loose fragments under the flywheel, such as fragments of magnets? Can you remove the flywheel without turning it, something may have come apart under it, and if you turn the flywheel you might cause more serious damage.
Tell us what you find.

[WhiteKnuckles]

The rubber came from the prop area. There are actually pieces still clinging to it. They are very thin, like a heavy rubber glove. I'll have to take a look under the fly wheel after work. Thanks for your reply.

[Solarman]

dt40, '97, backfire

The rubber sounds like a grommet, possibly the grommet from exhaust hosting to exhaust outlet in the midsection. It may have dry rotted and dropped into the lower unit, then to the prop. You should remove the gear case/ foot, and remove what's remaining. Would inspect all the grommets in the lower unit between exhaust and water section. There are several grommets that seal between the two Chambers.
You might be able to check the grommet in midsection with flashlight and your finger to see if it's still intact?
Let us know what you find. And under flywheel.