96 SPX Lean

[The_Doctor]

Hey guys,

I just put new plugs in my seadoo a couple weeks ago and noticed after checking the colour of them, they are very lean. They are not tan at all. The last set i pulled out were a nice coffee colour. My question is, if my engine is that lean, would it still run good and have lots of power? Its got good pick up, no real bog or hesitation. The fuel lines were changed last year, carb filters cleaned. I replaced the fuel filter housing and fuel selector valve this year. Any thoughts as to what would be causing my engine to run so lean?

I did a short wot run and pulled the lanyard, plugs were still too light for my liking.

 

[kmarts]

Did you ever rebuild and clean the carbs?

If so the look for an air leak

 

[mwat65]

Don’t run it more than u have to for testing until u get it fixed. You’ll melt your topend .

 

[The_Doctor]

Ya im trying not to...cause i know i can kill the top end if its too lean. Im gonna check the adjusters on the carb and see what they are at and make adjustments as necessary.
Hopefully i can make it a bit more rich.

 

[mwat65]

Did you replace the selector with oem. The aftermarket ones are junk.

 

[The_Doctor]

Ya oem from osd marine.
I know the carbs need to be rebuilt and i plan on doing it over the winter while they are stored away. I am just hoping i can get it to run safely (more rich) for the next month and a bit before i winterize them.

 

[kmarts]

If you know you have a lean condition you need to figure out why. you're not going to be able to richen up a fuel restriction with turning out the jets. With an air leak you *may* get away with it. But is it worth the risk?

A two stroke runs best right before it melts down from being lean, you'll get no warning and it'll be toast. Your ski, your money... But i would just accept that i can't ride it until it's fixed because the alternative is $$$. I've been where you are and spent a good chunk of this summer fixing more than riding.

TBH it's probably best you start now so you have the remainder of the season to water test. Otherwise you may rebuild the carbs over the winter to realize next season that wasn't your issue and then spend the start of next season finding your real problem.

When you pulled your plugs to see they weren't tan at all... Did you happen to see any metallic color on them? If so you really don't want to ride it any more.

 

[The_Doctor]

If you know you have a lean condition you need to figure out why. you're not going to be able to richen up a fuel restriction with turning out the jets. With an air leak you *may* get away with it. But is it worth the risk?

A two stroke runs best right before it melts down from being lean, you'll get no warning and it'll be toast. Your ski, your money... But i would just accept that i can't ride it until it's fixed because the alternative is $$$. I've been where you are and spent a good chunk of this summer fixing more than riding.

TBH it's probably best you start now so you have the remainder of the season to water test. Otherwise you may rebuild the carbs over the winter to realize next season that wasn't your issue and then spend the start of next season finding your real problem.

When you pulled your plugs to see they weren't tan at all... Did you happen to see any metallic color on them? If so you really don't want to ride it any more.

Everything you said makes sense. I really dont want to push it and blow thr top end before the end of the season...that would suck.

I dont think i have an air leak. Ive gotta check and spray some wd-40 around the engine and see if the idle picks up.
But like i said, it runs pretty good for a 20 year ski, minus the lean looking plugs.

Like i said, ive pretty much replaced everything in the fuel system (valve, fuel filter, fuel lines). The only thing i havent rebuilt would be the carbs. Which probably isnt a bad idea for a peice of mind and that way i know i am getting proper fuel delivery.

Ive also been running higher octane fuel (no ethanol). Could that cause it to burn hotter becuase higher octane fuel burns slower? I was just thinking about that the other day.

 

[kmarts]

Everything you said makes sense. I really dont want to push it and blow thr top end before the end of the season...that would suck.

I dont think i have an air leak. Ive gotta check and spray some wd-40 around the engine and see if the idle picks up.
But like i said, it runs pretty good for a 20 year ski, minus the lean looking plugs.

Like i said, ive pretty much replaced everything in the fuel system (valve, fuel filter, fuel lines). The only thing i havent rebuilt would be the carbs. Which probably isnt a bad idea for a peice of mind and that way i know i am getting proper fuel delivery.

Ive also been running higher octane fuel (no ethanol). Could that cause it to burn hotter becuase higher octane fuel burns slower? I was just thinking about that the other day.

I don't think that the octane rating is going to make any difference. What i run depends on where i fill up, on the water is 93, on the way to the lake i fill 89 at the gas station and i still get regular plug color. But when i was lean my plugs were pale and i did exactly what you want to do (richen the jets) with little difference.

How it runs can be deceiving. Mine appeared to run ok except an off idle bog/hesitation when in the water. I took my carbs apart 4-5 times after rebuilding making sure they were clean clean clean and it made no difference. I was probably more in denial than anything because i knew based on the age of it the probability of a bad seal was high. When i finally caved and checked it i found exactly that.

Not saying that's your problem, just was my experience. Pain in the a$$ but i want to keep it for a couple years at least lol.

Good luck.

 

[The_Doctor]

I don't think that the octane rating is going to make any difference. What i run depends on where i fill up, on the water is 93, on the way to the lake i fill 89 at the gas station and i still get regular plug color. But when i was lean my plugs were pale and i did exactly what you want to do (richen the jets) with little difference.

How it runs can be deceiving. Mine appeared to run ok except an off idle bog/hesitation when in the water. I took my carbs apart 4-5 times after rebuilding making sure they were clean clean clean and it made no difference. I was probably more in denial than anything because i knew based on the age of it the probability of a bad seal was high. When i finally caved and checked it i found exactly that.

Not saying that's your problem, just was my experience. Pain in the a$$ but i want to keep it for a couple years at least lol.

Good luck.

Okay thanks for the input on the gas situation. I didnt think it would but then i started second guessing my self.

Its really deceiving because it seems to run really smooth and have good power. I got 50mph on a gps with it a couple weeks ago. Compression is 140ish on both cylinders.

I just dont want to rebuild the carbs and still be crazy lean. That would be a real piss off. What seal was bad on your seadoo? And what motor was it?

Thanks for all your help. Much appreciated.

 

[kmarts]

Okay thanks for the input on the gas situation. I didnt think it would but then i started second guessing my self.

Its really deceiving because it seems to run really smooth and have good power. I got 50mph on a gps with it a couple weeks ago. Compression is 140ish on both cylinders.

I just dont want to rebuild the carbs and still be crazy lean. That would be a real piss off. What seal was bad on your seadoo? And what motor was it?

Thanks for all your help. Much appreciated.

It's like you're talking about my ski lol, other than the off idle bog it ran fine otherwise and i hit 56 on the dream-o-meter @ WOT.

97 GSX, 787 motor. It was my outer PTO crank seal. My carbs were plugged and needed to be rebuilt so i would have had to do it anyway.

Start with the wd-40 spraying first like i wish i did, I wasted so much time screwing with the carbs after i rebuilt them...

 

[mikidymac]

Stop wasting your time and money. You haven't done the carbs and are lean. As everyone keeps telling you, rebuild your carbs.

You have done everything else and the problem is still there and 99.9% of the time it's the carbs on these. If you keep trying to get ti by for the rest of the season plan on an engine rebuild over the winter along with the carbs.

 

[The_Doctor]

Okay. Thanks for all the help and input. Im gonna order the carb rebuild kit from OSD now. Hopefully this takes care of my issue.