Rough Idling at times

[Jono6716]

Hey everyone,

I was just reading a forum and i wanted to ask you guys a question. I have a 99 Seadoo GTX RFi and when i am idling it sounds like it runs a little rough. It doesn't do it the entire time i am idling, but like every 5 to 6 seconds i will get a rough ergh noise that will last for about a second or two. I was just wondering if maybe i turned the idling screw up a little if this would fix it or if maybe there is something else going on? however, If i hold the throttle up just a little, it runs fine. I have changed the spark plugs and trimmed the wire and re-inserted into the boot but it didn't seem to make a difference. The ski runs great otherwise! haven't done a compression check in awhile, maybe i should? I dunno. Let me know what you guys think.

Thanks.

 

[timmyboy76]

how olds the gas, or gap in plugs right?

 

[Jono6716]

Well, I run premium gas in it all the time and I did gap the plugs according to the shop manual. The gas normally only sits in the tank for 2 weeks at most. I fill it up every time i go out.

 

[seadoosnipe]

octane...

In the manual, it states you run 87 octane fuel.

You say you changed the plugs and gapped them.....how did they look when you pulled them?

You can look at the bottom of my signature and find a link to snipes korner. There, you'll find a page on readin your spark plugs. Only if you need it.

When you read the plugs, you should be in the position that your having the problem with. Let it run in that rough condition then, hit the kill switch. Pull the plugs right then and see what they look like. It does sound like a possible problem in the gap............:cheers:

 

[Jono6716]

Octane!

Yeah, I did read that in the manual however i always heard to run premium fuel in the RFI. I may go ahead and go back to 87 octane. Do you think the higher octane might be the culprit? Is that possible?

As in regards to the spark plugs, I switched the plugs because of this problem, and the old plugs seemed to show normal wear (black) with little deposit on them. However, i had just bought this ski last year and the plugs were in the ski when i bought it. I gaped the new ones and installed them and the problem seems to be the same as before. I'll have to compare them to your pictures in snipes Korner, and go from there. I appreciate the help guys.

 

[seadoosnipe]

fuel selection?....

With the RFI engine (or any injected), I'd be more in tune with using a fuel with a cleaner in it, like Chevron's "Techron" additive. Though most manafacturers use additives in their fuel to clean injectors, not all do. I will not assume that your buying cheap gas. I think we all know the importance in good fuel, that's a given.

If you are using fuels with ethanol, this may be another thing to look at. I've been trying to get some good info on this, since it seems most states will be required to have a certain percentage added to gasoline by 2012.

 

[Jono6716]

yeah, I normally use Marathon gas due to it having STP additives. However, every time I put Premium gasoline in the seadoo, i think about how long that gas has been in the tank vs. how long the 87 grade has been in the tank. As you all know pretty much everyone uses 87 due to the gas prices unless their car requires a higher grade. Maybe i should try the 87 a few times and see how it acts. As they say, Ohio is the dumping grounds for all the bad gas. ha ha :hurray:

 

[seadoosnipe]

Good point!

You've got a good point. The regular gas being the most used, would be fresher.
:cheers: