Seadoo challenger exhaust question

Liberty44140

hoping that the experts dude and zav have advice on this one. Again I’ve got a 1996 sea doo challenger 800 jet boat with a single 787. Used it for the first time this season yesterday and it ran great. I opened up the engine room to have a look mid run because I rebuilt the raves this spring. All good. Later after we took it out of the water we noticed exhaust smoke in the engine room. Cleared pretty quick after opening.  We did power it up on to the trailer so the pipe was submerged for a bit with it running, it sat on and idled at an angle while I cranked for a bit, and when we gave it a quick start stop on the trailer to clear water the wind was strong directly behind us. 

Is it possible to have some exhaust back up in to the engine room while she sat half on the trailer running in the water or does there have to be a leak somewhere?

Dude_Himself

Probably a leak somewhere, but should be easy to fix. The hose clamps where rubber hose joins metal tend to be the culprit from my experience - either they loosen with time or get over-tightened and strip/snap.

Dude_Himself

Oh, have heard about cracked Purple Pipes - but they're easy to remove and replace as well for inspection.

zaverin1

Ye
deff check your exhaust components for a possible leak.

manifold
down pipe 
water box 
etc 

Liberty44140

Thanks, I'll put her in this weekend and have a close look while its running. Hopefully its no more than a hose clamp but I'll look at the purple pipe too. Could running it for a while on the trailer on the ramp with the exhaust low in the water have caused a leak or would it be a total coincidence?

While I have you, should the red rave cap's be screwed in all the way, or level with the black top? They were screwed all the way in but I read lots of posts that they should be level so I moved them to level when I re built. THANKS!

zaverin1

Level and yes shouldn’t get any regardless of the boat position 

Liberty44140

Got it, thanks. 

Dude_Himself

When you rebuilt the rave valves - they're not leaking - correct? I recall adding oring's to mine to better seal, or maybe replacing them. It's been 8 years...

Liberty44140

The rear rave had a slight occasional drip last summer which is why I rebuilt them. The old bellows were hard, new are nice and soft. The rebuild kit is the o ring, bellow, and gasket, so those are all new now. I checked them after running this sat and did see a little oil under the rear rave but honestly it could have been there pre rebuild. From what I've read a slight occasional drip on a boat this old isn't that unusual. I will be checking them along with the exhaust for leaks this weekend. I also read that replacing the spring seal rings on the bellows with zip ties is a good idea to seal from drips. Thoughts?

Dude_Himself

I meant leaking exhaust - but similar. The RAVE valves are there to build exhaust backpressure (when required to make better HP). If they're not functional it could block the exhaust - forcing it out weak seals (like the ones in the RAVE itself or anywhere there's metal-rubber connection). I'd start running on a trailer (with water) and a thin-bristled paint brush (or talc powder). That'll make it easier to detect the exhaust gas escaping.

Liberty44140

Got it, thx 

Liberty44140

Found the leak! Previous weld is not holding. Already at shop for re welding 

zaverin1

Yep