1997 Seadoo Challenger 1800 (787s)- Dies Midrange

[Hunter77ah]

Hey Guys,

I have a 1997 Seadoo Challenger 1800 with twin 787s. Doing a refurb on it and having some issues.

Low speed and high speed are fine, but there is an issue in the midrange. Between 2500-3000(ish) rpm, it has a tendency (80+% of the time) to bog and die (both engines). Once it gets past the stall point, it runs great. I replaced the fuel lines, the selection switches, cleaned/replaced the rave valves, the fuel filters, and rebuilt one set of carbs (using OEM parts). I've also played around with the air screws. Nothing has helped. Any suggestions? It makes it really hard to tow anything. Hoping to get it fixed before this spring.

Thanks in advance!

 

[Doug Overkill]

As described In the awesome 787 Carb thread
The Seadoo Carb Rebuild Thread

The pilot circuit cleaning includes 3 holes that need carb cleaner to flow VERY WELL out of each of these. 2 are pretty little holes and I had a similar experience to what you describe when one of those weren’t as clean as needed.

Your scenario is a little weird as both motors behaving the same but I would start here.

 

[Hunter77ah]

As described In the awesome 787 Carb thread
The Seadoo Carb Rebuild Thread

The pilot circuit cleaning includes 3 holes that need carb cleaner to flow VERY WELL out of each of these. 2 are pretty little holes and I had a similar experience to what you describe when one of those weren’t as clean as needed.

Your scenario is a little weird as both motors behaving the same but I would start here.

Thank you. I'll give it a try. I tossed them in the ultrasonic cleaner and then used a bit of carb cleaner. I'll double check the pilot circuit.