Need more bottom end

P

puijken

Location
Belgium
Hi,

I have a 2016 Superjet currently fully stock. I used to have a 2007 and it's about the 5th year now I'm riding Superjets. I'm getting used to it and I'm looking for some more bottom end power.

Top speed does not matter that much, I don't do a lot of WOT-runs and the circuit we have in the water is short enough to have just enough with the default top. We do a lot of freestyle and just foolin around and I would like to give the Superjet some more power.

Mainly make it more aggressive and giving it an extra punch on low speeds/rpm. For the handling I do not want to change anything at this time, so ride-plate and intake are not an option as they will also change the behaviour of the ski.

I was thinking about a b-pipe and msd enhancer myself but I'm open to other suggestions too. A fellow Superjet rider said to not spend any money on the exhaust and go for 760cc cilinder heads and the msd enhancer. He said everything can be stock with just the cilinders changed... (seemed weird to me). So I'm looking for some extra input.

Investment wise would be around the same according to my finds (1300-1500 euro). I want to keep it as reliable as possible too, because the stock Superjet are just crazy, you can run them a lot and never get anything big on it.
 
SuperJet-Dave

SuperJet-Dave

Location
Rochester, NY
Adjusting your low end adjustment screws in the carbs a simple thing to try. Making them as lean as possible (turning in - clockwise) without making the engine stall is your best bet. You can always adjust the idle screw (where the throttle cable is) to compensate the stalling when idling as well.
Sometime this makes a noticeable difference, sometimes it does not. Kind of depends on where it is set now. If stock it is likely at 1.5 turns out. Going to 1.25 or 1 could be the ticket.
Have fun!
 
V

Vortex

Location
Southeast
A light flywheel will help and is a simple way to get the ski to rev up faster. However they are not as strong so you need to be careful pulling them when youre disassembling the front cover.
 
Citizen

Citizen

Location
Coeur D' Alene, ID
SuperJet-Dave said:
Adjusting your low end adjustment screws in the carbs a simple thing to try. Making them as lean as possible (turning in - clockwise) without making the engine stall is your best bet. You can always adjust the idle screw (where the throttle cable is) to compensate the stalling when idling as well.
Sometime this makes a noticeable difference, sometimes it does not. Kind of depends on where it is set now. If stock it is likely at 1.5 turns out. Going to 1.25 or 1 could be the ticket.
Have fun!
Click to expand...

Sounds like a good way to blow up a motor. Tune the carbs right, not lean.

ADA head to bump up compression, bpipe, lightened flywheel, MSD, 9/15 prop. All these are noticeable upgrades, but you really notice the difference once they are all complimenting each other.

Personally I would do the Bpipe and ADA head, that should bring you in under budget and will give you best gains for the money. Could prolly slip a 9/15 prop in that budget too and you would be very happy.


760cyl actually has worse bottom end than the 701 due to port timing differences if I recall correctly, so avoid that at all costs.
 
SuperJet-Dave

SuperJet-Dave

Location
Rochester, NY
Haha. You won’t blow your engine by tuning your carbs a little, but I know what you are getting at. Not suggesting to run lean, just leaner than stock setting. Simply adjusting the carbs a little leaner (if at stock setting) is a typical approach. Lots of threads on this.
 
P

puijken

Location
Belgium
Okay, thx for the replies! So went to the shop and came home with a b pipe limited and MSD enhancher.

Will be instelling it asap and really curious about the gains it will get me.

2 questions tough...

1. Rev limit on MSD is set on 8000rpm. Is this safe? I do not do a lot of WOT runs, but sometimes friends ride the ski and I do not want them to blow up the engine. So what is a safe value?

2. Carb jetting, the shop were I got the pipe said I would not need to change them. I looked at the manual where it stated guidelines for 700 feet above sea level with aftermarket fire arrestors. I’m at 0m above sea level and will use default air filter. Anyone has experience with this and the required jetting. Of course I will check the plugs after a run, but a experience from someone might be useful.
 
V

Vortex

Location
Southeast
puijken said:
Okay, thx for the replies! So went to the shop and came home with a b pipe limited and MSD enhancher.

Will be instelling it asap and really curious about the gains it will get me.

2 questions tough...

1. Rev limit on MSD is set on 8000rpm. Is this safe? I do not do a lot of WOT runs, but sometimes friends ride the ski and I do not want them to blow up the engine. So what is a safe value?

2. Carb jetting, the shop were I got the pipe said I would not need to change them. I looked at the manual where it stated guidelines for 700 feet above sea level with aftermarket fire arrestors. I’m at 0m above sea level and will use default air filter. Anyone has experience with this and the required jetting. Of course I will check the plugs after a run, but a experience from someone might be useful.
Click to expand...

8000 is probably fine. The idea is to never hit the rev limit. Msd may be a bit different, but the stock cdi has a "hard" rev limit. When you hit it, it goes into a limp mode and slows you down. Thia is why people upgrade to msd or modify the stock cdi when you have added performance and rpm to your motor.
 
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