2008 STX 15F Rough Idle Bad Gas?

kbain78 · 07-20-2009, 11:12 AM

I filled my kawi up with fuel before heading to the lake this weekend. Once I was in the water i noticed that it was idling really rough, almost like it was gonna cut off. Got out on the water and the ski would top out at 6000rpm/ 50mph wide open. It would sputter coming out of the hole and I noticed a tremendous power loss. My first thought was that maybe bad gas so i just ran it till it was almost empty and I filled back up at the dock and added some fuel treatment my buddy had with him. I got my top end back and it seems to run fine wide open and at cruising speeds but still idles rough. I also noticed that the exhaust fumes had a heavy gas oder, or is that due to burning the gas treatment? This is my first ski, 25hrs on it and never had any problems till now. I figure if anyone can help and save me some money its you guys. Thanks PWCToday community!

mirror · 07-21-2009, 02:53 PM

Change the plugs and it should clear up. I have had this same issue and it is usually a bad plug. Check around for prices as they differ from parts store to the next.

08stx15f · 07-21-2009, 07:39 PM

Try regapping the plugs and cleaning them before buying new ones. This will typically work and save you some money. That's all I did with mine at 20 hrs and they are still running great.

kbain78 · 07-22-2009, 08:40 AM

Thanks guys, but is it typical for these engines to foul plugs at only 20-25hrs?

rotortiller · 07-22-2009, 11:41 AM

I've got 48 hours on my plugs, pulled them at 40 hr and they looked great. Plugs foul from burning oil, poor compression or too rich F/A ratio. Not typical for JT1500 plugs to go so early. These are not 2-strokes

mirror · 07-22-2009, 03:50 PM

Did you take it in at 10 hours and have it serviced? Did they change the plugs? My wifes HO was service at 10 hours by a dealer that won't put their hands on it again. Late that season it was stalling and running terrible. I thought something was wrong with the gas or injection but it ended up being the plugs. I just changed them and it has run great ever since. I don't think the dealer ever changed the plugs after break in. Cleaning them seems fine, just pull them out and look at them and see what they look like. See if they all look the same or maybe one looks completely different.

shuswap · 07-22-2009, 05:07 PM

Jeeez.....and I run the same plugs, uncleaned, for YEARS!! It seems that when I get new ones......there is always one that is faulty and it runs worse.....even $40/each aircraft spark plugs.

mirror · 07-23-2009, 03:59 PM

I pay $5 each for my plugs and I thought I was ripped off.

puckoach · 07-24-2009, 09:52 AM

I'm at 140 + hours on original pluggs. Regular pump gas, which after 05 has been E10. Stabil over the winter in the gas.

A new set has been resting comfortably in the tool box for two years, at $7 plus each.

What are you running, and where you getting them for less than that ?

To the original question, the color of the pluggs is important. Also, as tourque is pretty low, you might have a loose one from "vibration".... Pull them, color should be the same, slight difference for rear one ok. Huge difference on one indicates a problem.

mirror · 07-24-2009, 12:49 PM

Advance Auto Parts set of 4 25.64