Super Jet Superjet Jetting advice needed
- Thread starter T War
- Start date
- Location
- Cottage grove
which coffman pipe?
start with 2.0 needle seat 65g spring 135 main jet and 120 pilot
might have to move up to 138-145 main or even raise the pilot a little.
its called "tuning" for a reason
start with 2.0 needle seat 65g spring 135 main jet and 120 pilot
might have to move up to 138-145 main or even raise the pilot a little.
its called "tuning" for a reason
I did some tuning over the weekend and didn't get it all settled in.
I ended up with the following, which is still off.
2.0 N&S
Black Spring
3/4 turns out LSN
125 low
140 High
2 turns out HSN
I am way too rich on the bottom.
It runs and idles fine.
If I punch it from Idle -10% throttle I have zero hesitation
1/4 throttle for 1 minute then punch and it has to clear out but then goes.
I tried 120 and I thought it was rich and went to 115 and got significant lean hesitation, or so I think (Sounded like RPS dropped for a split second then took off). I had trouble telling if 120 was rich or lean, so I went with 125. I think it is rich, because I had to do only 3/4 turns out on the LSN to keep it running.
50% throttle test to WOT I have no hesitation at all
75% throttle test is tough because I get no change in engine speed. It seems to reach full RPM's at 75%. (Testing done on trailer)
Plugs look like dark chocolate, but dry. (Tells me rich)
After running at 25-50% throttle and then falling off the engine dies from too much gas. Also after a turn sub or other maneuver where I punch the throttle and let off I am loaded up and have to clear it out before I have power to go.
I am thinking I need to drop down to the 120 pilot jet. Any advice on the pop-off?
I also noticed more vibration from the engine at idle than i remember. At 25% throttle it is smooth, but not at idle.
Over the winter the ski got a high compression head, new reeds, porting and gaskets (passed air leak test), impeller.
It screams on the top end. I just need to finish getting the low end adjusted and need some advice from the pros.
I ended up with the following, which is still off.
2.0 N&S
Black Spring
3/4 turns out LSN
125 low
140 High
2 turns out HSN
I am way too rich on the bottom.
It runs and idles fine.
If I punch it from Idle -10% throttle I have zero hesitation
1/4 throttle for 1 minute then punch and it has to clear out but then goes.
I tried 120 and I thought it was rich and went to 115 and got significant lean hesitation, or so I think (Sounded like RPS dropped for a split second then took off). I had trouble telling if 120 was rich or lean, so I went with 125. I think it is rich, because I had to do only 3/4 turns out on the LSN to keep it running.
50% throttle test to WOT I have no hesitation at all
75% throttle test is tough because I get no change in engine speed. It seems to reach full RPM's at 75%. (Testing done on trailer)
Plugs look like dark chocolate, but dry. (Tells me rich)
After running at 25-50% throttle and then falling off the engine dies from too much gas. Also after a turn sub or other maneuver where I punch the throttle and let off I am loaded up and have to clear it out before I have power to go.
I am thinking I need to drop down to the 120 pilot jet. Any advice on the pop-off?
I also noticed more vibration from the engine at idle than i remember. At 25% throttle it is smooth, but not at idle.
Over the winter the ski got a high compression head, new reeds, porting and gaskets (passed air leak test), impeller.
It screams on the top end. I just need to finish getting the low end adjusted and need some advice from the pros.