seadoo backfire

[graphicideas1]

I have a new to me '97 seadoo xp 787. I ran it off the hose a few times this year. Today I went to start it and it ran for 10 seconds and I forgot to get the water hose ready. I killed the engine, got hose ready and when I tried to restart I got a VERY loud backfire. I waited 10 seconds started again and it seemed fine. What could cause that and should I be concerned? Also when on the hose they never seem to rev up good. Is that because they are out out the water?

 

[BMANN06]

IMO if this is a first occurance and you have successfully ran it again, I wouldn't stress on it. If it's an ongoing issue could be a few things (rotary valve timing/clearance etc). I just rebuilt my carbs over the winter and when I put them back in last weekend, I used a gas/oil mixture in and old windex bottle to help get them primed (spraying into carbs to get motors going and get the fuel pump primed) during this I had an occurance of a backfire but once everything was runnnin' I was good to go. Post back if its ongoing i'm sure you'll get some responses from the experienced members of the forum.

 

[BMANN06]

Also when on the hose they never seem to rev up good. Is that because they are out out the water?

There is a rev limiter in neutral I believe it to be somewhere between 3-4K RPM, On the trailer at idle with hose you should be sitting at 3K RPM and 1500K RPM idle in water.

 

[Bills86e]

There is a rev limiter in neutral I believe it to be somewhere between 3-4K RPM, On the trailer at idle with hose you should be sitting at 3K RPM and 1500K RPM idle in water.

Just too much gas in intake. '97XP's don't have neutral, its direct drive. No reverse bucket. You should set idle at 1350-1400 in the water.

 

[graphicideas1]

Just too much gas in intake. '97XP's don't have neutral, its direct drive. No reverse bucket. You should set idle at 1350-1400 in the water.

So would you not worry? Should the not run great on the hose at 1/2 to full throttle?

 

[graphicideas1]

? ?

 

[BMANN06]

I wouldn't worry about it if you just had a single occurance. Again post back if it is a consisent problem.

 

[BMANN06]

Just too much gas in intake. '97XP's don't have neutral, its direct drive. No reverse bucket. You should set idle at 1350-1400 in the water.

Thanks Bill, I'm still learning and trying to help where I can. I assumed the idle would be the same for each vessel with 787, although now thinking about it, it would makes sense for a smaller vessel to have a lower RPM ...