it's been a while since i've read about cutting the carb springs, and wanted to know if those of you that have done it are happy with the outcome. also was there a noticeable outcome and what was the outcome?

 

Cutting the carb spring is something I first suggested, it goes along with a list of other things to do for optimum performance at low cost. Here's the list again for owners of new machines or those that havent been monkeyed with yet.

Stock needle set in richest position
170 main (mikuni)
cut 4 coils off spring
air lid on!
87octane
Billet End Cap

This is the setup I ran at the ATPT Nationals, I will let others testify to how well my machine was running. I personally do not suggest drilling holes in the slide because I have no R&D or dyno time with that modification.


MrHorsepower

 

87 octane eh?

 

I cut out all my springs and put in a lectron [img]i/expressions/face-icon-small-smile.gif[/img]

 

so can you maybe put a reason behind each of your changes as to why you did it and what are the outcomes. like why 87 octane, why air lid on...etc. why will it run better with this setup. thanks

 

I think this is the story. Higher the octane #, SLOWER the fuel burns, at a given comustion chamber pressure. Let's talk about that stock DS. At WOT and 6500 rpm let's say the cdi is advancing the spark 32 degrees (fictional but probably within plus or minus 5)If a/f mixture detonates at 300 psi (fiction again)then the spark lights off a 190 psi charge.From 32 BTDC to 0 TDC the fuel is quickly burning, raising the combustion chamber pressure to say 290 psi then we're past TDC and burn and pressure rates increase fast. Now we try it again with hi-test,er ,93 octane in the tank.At WOT & 6500 rpm, 32 BTDC we light off that same 190 psi charge. Along comes 0 TDC and low and behold, our combustion chamber pressure is only 280 psi a 10 psi drop from regular unleaded # of 290 psi. Why, because the slower burning a/f mixture hasn't had time to raise the pressure that high. The efficient engine will get as close to detonation as possible before TDC and MisterHP knows that, that is the reason he runs 87 octane and wins races. Scoddee

 

[img]i/expressions/face-icon-small-wink.gif[/img] I got rid of my stock carb and switched to the lectron 46 HV as well![img]i/expressions/face-icon-small-smile.gif[/img]

 

Yes I'll be glad to explain, although most people wont believe me.

stock needle: because its already paid for
170 main(mikuni): I knew Bombardier had more research in jetting than Dyno Jet so the 165 was a good place to start
cut 4 coils: this gives better throttle responce because the vacuum slide doesnt have to work as hard pushing against a stiff spring, it also allows the slide to open all the way up
air lid on: after many many dyno pulls I can say you WILL lose as much as 5HP removing the air lid, the air intake system is designed to work with a vacuum slide carb. When the lid comes off vacuum is lost in the tube that goes from the air box to the carb. This loss of vacuum will not let the slide open properly and causes the slide to fluctuate up and down at a very high rate of speed. This is further confused by the fact that bottom end throttle responce is improved(with lid off) from idle to about 3500 rpm which give a false sense of more power everywhere
87octane:This a real cheap way to increase your timing
Billet End Cap:this is a simple bolt on to the end of your stock exhaust

As good as this stock carb setup works, I'm with MudStud, the Lectron blows it away.


MrHorsepower

 

The following must be sung.






itsy bitsy raptor trying to get to the dunes top; [img]i/expressions/face-icon-small-wink.gif[/img]
outcome the ds and makes the raptor look like a flop. [img]i/expressions/face-icon-small-blush.gif[/img]
outcome the preditor thinking a bad thought makes the ds mad so it destroys the preditor which makes the owner wonder what kind of junk he bought.[img]i/expressions/face-icon-small-mad.gif[/img]
outcome the ds still mad even though the winner and makes the preditor its chicken dinner [img]i/expressions/face-icon-small-happy.gif[/img]




work in progress???[img]i/expressions/face-icon-small-wink.gif[/img]

 

well i was using it because i was bein cheap, and it ran fine on it, now that explains y i can eat raptors
[img]i/expressions/face-icon-small-happy.gif[/img]