Fouled Spark Plugs

[etemplet]

When I took the skis out for first ride after maintenance I had a couple of fouled spark plugs and my old 2 stroke days have me wondering if the type of oil I am using is could cause the problem. I purchased Mystik Full Synthetic from Academy. I did have the 32:1 Mix and I fouled plugs on two separate skis. Only one plug each though so not a big problem. Back in the day cheap oil would cause this as Mystik is cheap but the correct stuff for the ski. The other oil is about $15 more per gallon so something has to be different. I only fouled 2 plugs one each on different skis in two days.


1. I removed the oil pumps on all the skis so I premix the fuel.
2. It was a short trip to the open water so I would say there excessive idling.
3. The plugs were not new on one of the skis.
4 Perhaps the excessive oil premix is a contributing factor.

I am going to do some oil research and try different heat range plugs. The carbs have all been rebuilt but perhaps there is an opportunity for further adjustment. We are having fun so I didn't troubleshoot too much.

 

[snikwad003]

40:1 is the proper ratio if you're not on break in and premixing helps foul them out, my boat needed new plugs twice last year and if it was on oil injection it probably wouldn't have needed them until the dewinterizing from the fogging oil. We just got an academy so I'll probably switch to the mystic since it's on the shelf and quite a bit cheaper. They have several tcw-3s in the silver bottle on the same shelf so you gotta be careful.

 

[Digdog]

When I took the skis out for first ride after maintenance I had a couple of fouled spark plugs and my old 2 stroke days have me wondering if the type of oil I am using is could cause the problem. I purchased Mystik Full Synthetic from Academy. I did have the 32:1 Mix and I fouled plugs on two separate skis. Only one plug each though so not a big problem. Back in the day cheap oil would cause this as Mystik is cheap but the correct stuff for the ski. The other oil is about $15 more per gallon so something has to be different. I only fouled 2 plugs one each on different skis in two days.


1. I removed the oil pumps on all the skis so I premix the fuel.
2. It was a short trip to the open water so I would say there excessive idling.
3. The plugs were not new on one of the skis.
4 Perhaps the excessive oil premix is a contributing factor.

I am going to do some oil research and try different heat range plugs. The carbs have all been rebuilt but perhaps there is an opportunity for further adjustment. We are having fun so I didn't troubleshoot too much.

Sometimes it is the fuel that causes fouling, try changing brands and see. I would look at jetting before changing heat range of your plugs.

 

[mikidymac]

The fuel brand will not cause fouling. It is too much fuel, too much oil, too much idling or a combination of all. Do not change the heat range of the plugs. If it were me I would go back to the oil injection and make sure your carbs are set correctly.

 

[etemplet]

Well, I am on 32:1 because of break in on both skis and I fogged them both last year and ran them without changing or cleaning the plugs. . Now all the skis will all be on 40:1 I think most of this will clear up as I ride more. I found fuel stations that do all ranges of "No Ethanol". I am also going to tweak the carbs on the skis and get them spot on. I am gonna be a primo carb tweaker when I am done. LOL