3d base bogging down at full throttle

[Sparkiebates]

First of of I'll say hi. I'm new to these forums but I have found them useful in the past so I thought I'd see if any 2 can help.

I have a 3G 2004 787 cc. It's done 9 hrs, I've had it for 3 years. I wa out in it all last year and left it in the garage all winter. I got it out 3 days ago and it was fine. I took it out today and it seems to be bogging down at full throttle. I've checked plugs, compression and fuel and injectors but all seem ok.
Also I noticed when I start it out of the water with a hose it runs on 1 cylinder for a little while then you hear the other kick in? I removed the first plug when it was running and the engine died but when I removed the second plug it stayed running.

I would appreciate a little help or a point in the right direction, so hopefully I'll be back on the water soon. Thanks, Lee


Thanks

 

[1MACGYVER]

They only run on the front cyl at idle and the second kicks in at 2000 or so rpm, thats why if you idle it around too much the rear plug fouls.

Did you get the injectors tested or just a visual?, mine did a similar thing and a few tanks with injector cleaner has got it running like a dream. the other thing i'd check is the bottom strainer filter on the fuel sender unit

 

[Sparkiebates]

Firstly, thanks for tour reply.

I've checked the injectors work by taking the injector rail off and turning the engine over, they both spray the same amount. I've read in another post about the 1 cylinder but I can't get this round my head. The reason I say this is because I've personally checked that both plugs spark an both injectors spray on turn over of the engine. Why would it be like this if only 1 cylinder is being used on tickover? I'd like a little more info into this if you could please.

Also everything I take off to clean/replace ie fuel filters, plugs, rave valves etc all look like new. The ski has only done 9hrs use. No engine lights come and it stats perfect. I can't understand what could be causing it to bog down on full throttle, 1 day it was fine all day then 2 days later I take it out, it starts doing this.

I really appreciate your help, it's 25c Celsius here in England not to mention the long bank holiday and royal wedding. It's like a 2 week holiday so no where is open.
Thanks again. Lee

 

[1MACGYVER]

I dont know a whole lot about it, my Seadoo Mechanic told me that they only run on the front at idle, with no fuel or spark but it still pull in air and oil, hence why it fouls the rear plug. He said the purpose of that was to reduce fuel consumption. It may run on both when first started to warm up, im not sure.

Im not denying what you say but it would explain: "I removed the first plug when it was running and the engine died but when I removed the second plug it stayed running. "

The only other thing i found that helped while mine was bogging down at WOT was to feather the throttle around 80-90% instead of holding it flat down and it ran a lot better.

Even though its done very low hours, only 9 hours in 7 years could be part of the problem, 2 strokes generally work on the theory 'use it or lose it' , after the tanks of injector cleaner and the more i run mine (25 hours in the last 3 months-since the rebuild) the better it runs.

I dont want to sound like a broken record but id give the injector cleaner a try, a visual test may not show the difference between a good one and a slightly blocked one.
Also id replace the plugs anyway, they are cheep and i was told cleaning them doesnt work as they are a resistance style plug

 

[Sparkiebates]

Thanks alot mate, I'll get the injectors tested then. And yes that's why I can't get my head around it all because I've prooved tree is spark and fuel but also prooved that only the first cylinder is working on tikover. It's a strange 1 as it's not even electrical it's common sense as a spark and fuel will ignite.

But once again, thank you very much for your help. I'll try the injector cleaner and let you no.

Regards Lee