I bought a polar kraft with a Nissan 40 hp with oil injection gravity fed. My question is I had to repair the neck where the line attaches. It was leaking. I made a small batch of epoxy and then after it dried on the neck I installed a very tight fitting new line. My question is does the tank build pressure in heat and when its running? If so I don't know if my repair will hold so I might just stop adding to tank and mix In gas tank. Will this hurt my motor? Its a 1998 Nissan. Thanks for any feed back.

I personally don't trust the gravity feed oil injection , all it has to do is malfunction once and the motor gets damaged . I mix my oil and gas on my 1993 30 hp evinrude at 50:1 . I mix it in 5 gallon cans so I can make sure the oil gets thoroughly mixed by shaking the can with 1 gallon then continue to fill the can .

I read where some motors are good with that and some will damage. I don't see how it will damage it but im no mechanic.