1999 Seadoo Challenger Oil in Cylinder 1 fouling out spark plugs

[JRO11]

Hi All,

I'm having an issue with a 99 Seadoo Challenger (787 Seadoo motor) where it constantly fouls out the spark plug in cylinder 1 after sitting for a few hours. I can get it started by removing the plug, turning the engine over for a few short 5 second bursts to remove the oil then putting in a new plug. Once the new spark plug is in it will start right up but smokes a lot due to the excess oil.

Has anyone come across this or a similar issue before? I'm hoping it's something simple such as a bad gasket...I'm just not sure where to start. Any help would be appreciated!

James

 

[kgray61340]

787 Engine NOTE: The adjustment nut and jam nut for the oil
injection pump cable are located at the cable support
on PTO side carburetor use a mirror to make sure marks are lined up

 

[martin18152]

Sounds similar to what happened to me. The oil injection system injects oil into the base of the carb, and a separate hose injects it down to the crank shaft bearing. What happens is a seal that keeps the oil in the bearing and out of the engine fails, oil starts to enter the crank and gets scavenged into the pistons, then the pistons will hydra lock, you can pull out the spark plugs and blow the oil out, and continue to run the engine. Mine did it after sitting for the winter, then when it got really bad, you could not get it to crank at all. Unfortunately some models, and maybe yours, has the seal integrated into the crank shaft, and the entire crank must be replaced. The crank cost me about 300 dollars.

 

[Dr Honda]

You've lost the seal in the crank. Not much you can do, other than split the engine, and replace the crank. But, if it's the original engine, then it's not worth doing that either.

Unfortunately... it happens, and I just replaced 2 engines in a Challenger, in a customer's boat for the same reason.

 

[JRO11]

That's too bad...thanks for the info guy's.

Dr Honda - Can you give me an idea of what it would cost to fix vs replacing the engine?

 

[Sportster-2001-951C-Stock]

What about the top seal on the rotary shaft itself, does that one not usually cause a similar problem?

I wouldn't know, just asking......

Anyway, I believe the service manual has a section for pressure leak checking the cavity, could try it out to confirm? If it's that bad, I bet the engine consumes lots of oil during running.... If there's lots of soot on the plug, a hotter one might help alleviate that some, like a BR7....?