ported engine theory. do I suck or does it suck?

[waxhead]

What compression do you have in the engine

 

[waxhead]

With big carbs you get to the point where the diffeence in throttle plate angle makes no difference as the engine has all it can deal with. This is why it seems you can give it more and it just gets louder not faster
So why big carbs. Because they give you mid range torque.
How is the water on your n-pipe set
What are the jets on the 44s. so much to be sorted before you determine why its doing this.
How strong are your arms, Most people love the hit ?

I have a 61x cylinder I had bored to 84mm and ported it myself using the port templates sold on here. I had a head shaved and cut for the 84mm bore and big race gas compression. In my old square nose, I put this on the stock 61x cases and carb, with a protec black pipe. This combo was very linear and great to ride.

Then I got a deal on a RN I couldn't pass us. I kept my cylinder and head from the square [just swapped them between skis and sold the SN] and put it on the RN. The differences are the RN has oem 760 dual 44's, and a limited chamber B pipe. It now rides exactly like your 91. Anything below half throttle, it is linear and adjustable. Right around half throttle, it explodes like a cannon and more throttle doesn't feel like it does much extra. Pretty sure 5/8ths throttle is about as fast as 8/8ths lol. Yes, its much faster now. But I really hate this light switch response. I want to be able to cruise at half throttle and get half throttle power.

 

[bored&stroked]

With big carbs you get to the point where the diffeence in throttle plate angle makes no difference as the engine has all it can deal with. This is why it seems you can give it more and it just gets louder not faster
So why big carbs. Because they give you mid range torque.
How is the water on your n-pipe set
What are the jets on the 44s. so much to be sorted before you determine why its doing this.
How strong are your arms, Most people love the hit ?

lol my point was to show the OP that porting does not influence the powerband like he was asking, as the same ported cylinder and head react very differently when different parts are bolted on.
Pipe is set same as it was before I put the engine in. I haven't played with it yet. Carbs are reverse jetted to your specs lol. I can hanlde the hit fine, its the lack of power adjustability I hate.

 

[kevbo]

Reverse jetting works great if you like to fan the throttle all the time as most riders do. If you are smooth on the throttle it will likely be horribly rich under the pipes operating range, 1/4-1/2 open throttle. Smooth throttle guys are much better off if they power tune the top screw rich of peak rpm then make the pilot just rich enough for good response. Using someone elses jetting specs is foolish at best.

 

[bored&stroked]

Reverse jetting works great if you like to fan the throttle all the time as most riders do. If you are smooth on the throttle it will likely be horribly rich under the pipes operating range, 1/4-1/2 open throttle. Smooth throttle guys are much better off if they power tune the top screw rich of peak rpm then make the pilot just rich enough for good response. Using someone elses jetting specs is foolish at best.

Ahh but using someone elses jetting specs for the same setup is a great starting basis. Especially when it starts great, idles great, and has excellent power. The rest is a matter of dialing in the combo [i hope]
Whats more foolish, using a known decent jetting setup from more then one source [the carb setup thread] and adjusting, or running the oem jetting and adjusting?

 

[kevbo]

Always start much richer than what you expect and lean from there. That is the safest way to tune since our engines are so easy to burn up. A strict freestyle ski can live with hotter main circuit jetting than one that is run full throttle for a long time. If its too rich at full throttle the rpm will be down, it may even fourcycle. Lean until RPM peaks then open the top screw a little to slow it down a few RPM. For freestyle do the same except go by how hard the ski pulls if full speed runs aren't possible or if you don't have a tach.

 

[waxhead]

BY fanning the throttle you actually keep the pipe temp up as well and it makes it hit harder. If you are a smooth throttle guy then the spec I gave you will not work. If you are using my jets spec then you are slightly rich on top. I always run one size smaller up top and then open the high screw up more. The 110 will still be slightly rich when you close it off