tuning issue

[yd_dc]

hey guys
put on girdle head w 35cc cones, limited bpipe, limited, removing one screen from carb filter, all of which need me to tune carbs and pipe.

what would the procedure be to tune both the carbs AND the pipe at once? do i need to set the carbs first then the pipe? or go back and forth between carbs and pipe until all set.

then when everything seems ine, will i ned to retune everything if i rejet? i will be trying both 135 and 140 main jet.


please do not tell me to use the search button as i have seen all the posts on tuning: they are either tuning carbs OR pipe.

tkx in advance

 

[tshank123]

tuning the pipe is more about rider preference. you should probably just set the screws on the pipe to the recommended starting position from Factory Pipe, like top and middle closed, bottom open 3/4 of a turn. Just make sure the chamber doesn't get too hot. Tune your carbs and then once you have them dialed, go back and start playing with the pipe. Once you get the pipe how you like it, you might want to go back and fine tune the carbs.

BTW - From what you're asking, it sound as if you may be confused about carb tuning. Adjusting the screws on the carbs are just for idle, and full throttle. Tuning carbs includes rejetting them and adjusting popoff pressure as well. I suggest you rejet your carbs to factory pipe's recommendation before taking the ski out for a ride with the new pipe.

 

[yd_dc]

so its a back and forth kinda adjustment btw carbs and pipe.
thats what i guessed.
however, people on this forum w same setup (lmited + 35cc cones which i guess is the most common easy setup around) have different preferences regarding jettings, so i would like to try both 135 and 140 main jet, as well as 95 and 115 g settings.

will i need to readjust pipe screws if i rejet?
btw, tkx for reply tshank123

 

[tshank123]

carb tuning/jetting etc. is not really preference. the optimal settings for your carbs are determined by what your motor/pipe/pump setup is. also, your elevation/temperature etc. factor in.

the other thing about carb tuning you need to understand is that every adjustment affects a different part of the throttle position. low screw for example only affects idle, high screw affects 3/4 throttle to full throttle. read the manual in this link. I think it will help you alot. Pay special attention to the chart on page 17.

http://www.mikuni.com/pdf/sbn_manual.pdf

tuning the pipe is more preference. what I mean by that is, do you want more low end, more top end, something in the middle? changing the water screw settings will change where in the powerband is in the pipe.

 

[yd_dc]

tkx alot for ur replies and info.
one last question, will adding a restrictor after water outlet from engine to keep temp at 120F but right before pipe affect the pipe s performance?
i will be runing single cooling.

 

[chriselmore_1]

youll get a little more bottom end and it might be slightly louder. if you restrict it too much your pipe will get too hot and melt your hose and stuff

 

[yd_dc]

so if i manage to get using a restrictor a temp of 120F without melting my pipe am all set. however, what are my options if i cant?

i am sure no past treads ever mentionned playing with restrictors to get the right engine temp FOR SINGLE cooling. (except for #zero who runs a system that can hardly be copied and matched)

 

[chriselmore_1]

if you are restricting just to manage temp you need to restrict the pissers.