- Location
- California
I could use some help from the collective before I start throwing parts at my ski.
Some of you might remember Project Boat Anchor https://www.x-h2o.com/threads/project-boat-anchor-superjet.193224/
So after 3 years of delays, no water in the lakes and a year recovering from back surgery my 13 yo son and I were going to take his 91 Superjet and Project White Trash https://www.x-h2o.com/threads/white-trash-build-440-650.201870/ to the lake on Monday for our first actual father son ride and that started with two cracked fuel tanks in Project White Trash so we dusted off Project Boat Anchor and put gas in them and it started up perfectly but would backfire out the exhaust as soon as you gave it some gas.
So the history is a stock build 701X/62T engine (Stock for 2001 SJ), JM crank, Pro-X pistons machined by Group K, and Yamanube porting templates and stock exhaust. The idea is after break in I am going to start adding parts just so I can feel the change with an ADA head from JM and a Wax full pipe.
Back when I finished the build it did the same thing so I started swapping out all the CDI and coil with my son's 701X parts and it ran perfect. I then swapped back my coil and CDI one by one and it still ran perfect. The ski has never been in the water and here we are 3 years later and back to the same misfire.
So ski starts and idles perfectly and as soon as you give it gas it starts to backfire out the exhaust and you can watch the breadbox rubber hose expand with each backfire.
I am pretty sure it is electrical.
I am thinking coil first as it is the least expensive then if that doesn't fix it I was going to buy a MSD Enhancer but they are $420 now, WTF? So thinking a Plug & Play 62T Zeel since they are cheaper and probably better.
Some of you might remember Project Boat Anchor https://www.x-h2o.com/threads/project-boat-anchor-superjet.193224/
So after 3 years of delays, no water in the lakes and a year recovering from back surgery my 13 yo son and I were going to take his 91 Superjet and Project White Trash https://www.x-h2o.com/threads/white-trash-build-440-650.201870/ to the lake on Monday for our first actual father son ride and that started with two cracked fuel tanks in Project White Trash so we dusted off Project Boat Anchor and put gas in them and it started up perfectly but would backfire out the exhaust as soon as you gave it some gas.
So the history is a stock build 701X/62T engine (Stock for 2001 SJ), JM crank, Pro-X pistons machined by Group K, and Yamanube porting templates and stock exhaust. The idea is after break in I am going to start adding parts just so I can feel the change with an ADA head from JM and a Wax full pipe.
Back when I finished the build it did the same thing so I started swapping out all the CDI and coil with my son's 701X parts and it ran perfect. I then swapped back my coil and CDI one by one and it still ran perfect. The ski has never been in the water and here we are 3 years later and back to the same misfire.
So ski starts and idles perfectly and as soon as you give it gas it starts to backfire out the exhaust and you can watch the breadbox rubber hose expand with each backfire.
I am pretty sure it is electrical.
I am thinking coil first as it is the least expensive then if that doesn't fix it I was going to buy a MSD Enhancer but they are $420 now, WTF? So thinking a Plug & Play 62T Zeel since they are cheaper and probably better.
