Different Spark Plug Better Performe

[andyfen]

I Replace the Spark Plug from my Seadoo Speedster twin Engine Jet Boat, with a car's Spark plug. The performance is 75% better. The body of the Spark Plug is the same except the tip of the spark plug is longer, so that mean the combustion is nearer to the piston on TDC position. Question is: Because the fire produced now is more close to the piston, that the piston will get burn or weld with the time pass?

The Spark Plug is the one that I use in my Jeep Suzuki Samurai. I crank the engines with the old spark plug (NGKBR8ES) in cold weather pulling the choke to max position and it take 30sec to the first combustion and 30sec more to start. Then after 10sec a release the choke. So basically it take 1min + 10sec to start those engine. I have to wait about 2min before I put the full throttle if not the engine shot down.

With the Jeep Suzuki's Spark Plug it take 10sec to start and I can release the choke immediately. When I put the full Throttle it response with so much power that it take less than 3sec to get out from the Drag area.

But, probably is something else..............

 

[LouDoo]

Moving this to the 2-stroke sport boat forum.

It's pretty hard to believe that you're getting 75% better performance just by changing the spark plugs. Have you done anything else to the motor?
Generally it's not a good idea to use a spark plug other than stock, engine reliability will certainly be effected. You might get away with moving one range hotter but that's about as far as I would go.

Lou

 

[Seadoobuddy]

I agree with Lou.
OEM NGK plugs have been tried and tested to be the best for that motor.

How did you measure that you got 75% better performance?
What car plug did you use?

 

[Coastiejoe]

If you gained 75% in performance, I am guessing that one of the plugs you removed was defective and causing a serious lack of performance issues....

 

[ialonso]

What plug did you replace it with?