Fouling Plugs?

[travis_132]

I have a 91 SJ and am having a problem fouling spark plugs. I mixed the gas too rich and draind it all out of the tank and remixed 50:1 and put in new plugs. Now everytime i ride i can ride for about 10 minutes then it will just bog and die. I can ride it back to shore but can only give it about 1/3 throttle and anything over that it will instantly die. Any ideas? Thanks!

 

[ger87410]

That's a tuning issue. Assuming the carb is good.

I'm still working on that myself.

 

[travis_132]

Well it has ran fine in the same lake all summer long, then last weekend it started to run like crap. now i can ride for like 10 minutes then it does the same thing.

 

[ger87410]

Compression checked?

 

[cmeripper26]

Sounds like a carb issue. I would take your carbs off and open up the fuel pump side and check the internal filters. If there was old gas sitting in them for a decent amount of time the ethanol in the gas will clog up the filters allowing only a small amount of gas through the pump side. What do your plugs look like after riding and taking a plug reading?

 

[travis_132]

when i take the plugs out they are soaked, still making me think it is too rich, but i know the new gas i mixed is not rich.

 

[Scraggly]

leaking n/s? clean your carb and check the needle for deformation at the seal.

 

[Mark44]

leaking n/s? clean your carb and check the needle for deformation at the seal.

My guess also.

Mark44

 

[ger87410]

How rich is too rich?

I run ~40:1 in my SD all the time without issues.

 

[agua]

i run 50:1 and never had a problem with it

 

[travis_132]

i have always been mixing it 50:1 but i think i messed up and instead of doing 13 ounces of oil to 5 gallons of gas i did 16.

 

[tom21]

I've run 32:1 with no problems. possibly more on one particular break-in. got distracted and lost count so figured more was better then less. lol. it ran fine.

x3 on the n&s. and inspect the little checkvalve. its the thin clear part on the back of the block you remove to get at the jets.

 

[cmeripper26]

Agreed on the leaking Needle and seat. I would look at the Needle tip for damage where it wouldn't be sealing.

 

[SUPERTUNE]

Does it run good cold for like 3-5 mins?
Maybe you have some cooling line blockage and the over heat sensor is coming on and limiting the RPM's to 3000.
When this happens the plugs will come out fouled looking.

 

[SUPERTUNE]

i have always been mixing it 50:1 but i think i messed up and instead of doing 13 ounces of oil to 5 gallons of gas i did 16.

That is no problem, you should run 16 oz to five gallons, this is 40:1.
Just use Mercury Marine Quicksilver oil for a good burn at this ratio on a stock ski.

 

[CARBONX2]

Check for breaks in HT leads and pug-gap