Joined
·
337 Posts
I have a 1991 140hp Johnson that will not make it to its top end of 5500-6000 RPMS. Here are the things I have checked:
1. Fuel lines between tank an engine are fairly new. I replaced them 2 years ago, and all fittings are good and tight.
2. High speed jets are clear.
3. Good spark. I checked this when the motor was cold before putting it in the water if that matters.
4. Compression is an even 90 on all 4 cylinders. Not sure if that is where it should be though. I used two different gauges, one read all at 60psi and the other all at 90psi, so I am assuming 90 is correct.
When I throttle up, the boat will power up and plane fine, but it tops out at 30mph and 4000 rpms.
Any thoughts?
Thanks!
1. Fuel lines between tank an engine are fairly new. I replaced them 2 years ago, and all fittings are good and tight.
2. High speed jets are clear.
3. Good spark. I checked this when the motor was cold before putting it in the water if that matters.
4. Compression is an even 90 on all 4 cylinders. Not sure if that is where it should be though. I used two different gauges, one read all at 60psi and the other all at 90psi, so I am assuming 90 is correct.
When I throttle up, the boat will power up and plane fine, but it tops out at 30mph and 4000 rpms.
Any thoughts?
Thanks!