What size and kind of carbs are stock on the DS? What do you upgrade to if you go bigger? I am thinking of building a 2/1 for my Raptor and thaught I might get some usefull info about the DS's carbs.

 

Ward660R you due not hae to due Edelbrock has on now for the Raptor. http://www.barnumspro.com/proproductweb_013.htm

 

Stock DS carb is a Mikuni BSR42mm - same type of carb on the Raptor - constant velocity vacuum operated slide.
Common DS carb mods are TM45mm flatslide, and twin TM39mm flat slides.
Lectron 44 and 48 are becoming more popular too.

 

Thanks ya'll Bomber guys a pretty good in my book. I thaught about the edlebrock but I think that I can get a 45mm for free. It would take some crafty intake work but I think I could get it. Does TM or Lectron have a web site or do you know where I can look/buy one on the net? This might seem like a stu[id question what would the reasons be for a larger carb, mine would be for alky?

 

Sorry dude, I should've mentioned that TM is a flat slide model made by Mikuni. Many places deal with Mikuni carbs, Sudco has a website and is a popular supplier.
Lectron has a site, and a reputable dealer for them is called Fastbygast - tell them what you want and they'll help set you up.

Reason for larger carbs - more air flow. More air means more fuel can be burned. More of both means more power. Stock carbs are fine for stock motors, but when you start modiying stuff, it becomes possible to get more in and burn more.

Another reason for aftermarket carbs is style - the BSR carbs have a butterfly that causes some turbulance in the air flow, combined with a sometimes hesitant vacuum operated slide. Flat slide carbs like the Mikuni TM and the Lectrons have only a slide directly pulled by the throttle cable, for more instantaneous power without hesitation, and better air flow through the venturi due to no butterfly.

What size are raptor carbs? I was thinking they are 32mm? If so, they should flow more air than a single 45mm. Most highly modded DS's run twin 39mm, making twins the way to go - or stay in your case...

 

My stock ones are twin 33s. I was trying to get away from the vaccum style carb, when I jump or hit big bumps the slide seems to go with it causimg a stutter. I was also thinking about putting it on alky and I was told that it would be easier with a single set-up. Is there some formula or measurement that says which card out flows one another? Everyone that plays big on the Raptors says FCR but they are like $1,000, a little steep for me. Thanks for all the help.

 

Dynojet kit will cure your stutter, my DS was the same way before the new needle. Also, I know a few Raptor buddies who will swear by the dynojet kit too. Any performance issues you have are just in the tuning.
I don't know anything about alky, sorry.
I'm really not sure about the difference in flow between the 45 and the twin 33's, just guessing.

 

I had the DJ kit in and it didn't help. Right now I am back to the Mikunis. The only problem I have with this is trying to find a 175 main, one has been on back order for weeks.

 

No offense or anything, but honestly, the stutter issues are a product of being out of tune, and not the carb size or style. Either that, or there is a problem somewhere, like a clogged filter/screen, or vent tube.
175 main is the largest jet I've ever heard of being in a Raptor carb. Go to the Yam forum and get some advice from some of their resident experts in Raptor tuning.
Good luck.

 

Ward660R due not for get the dual 35 FCR from
http://www.sparksracing.com/Sparks_Frame_1.htm