Why is it that you see the DS guys swithching carbs for more power but not the Raptor guys? Is it that the DS is under carbed from the factory, or the Raptor won't head won't allow a bigger carb without port work? And if you see a carb on a Rappy its a FCR why not anything else?

 

Yeah, we were talking about this very same thing this last weekend. Why couldn't you use a single mikuni tm45 or tm48 or Keihin FCR with an intake to match, and even feed the rappy some alcohol? shhhhhh!!!

 

Well the way I understand it is you get more top end out of the twin 33s than one single. But why not use twin something else other than the FCRs? And what size carb would it take to match the stock top end of the 33s and still gain on the bottom.

 

Good question.

I can attest to the TM??45 carb for the bomb. It gave my brothers DS a 3-4 bike length advantage over my Raptor. We used to be relatively even and I'd get the holeshot most every time. Now (He has new XCT holeshot tires) he gets me off the line and pulls a tad all the way to the end of what I'd guess is a 800' + drag race. Though when I get my cam situation straitened out I believe it will even us out again and, I will have done it a few hundred dollars cheaper. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Ward, what (other than price) do you have against the FCR's? These carbs are awesome. Factory races teams could use any that the want but they choose the FCR. Yamaha passed over many cheaper carbs to pick the FCR for the 4-stroke YZ's. I own a 35 and the 39alky for the 250x and feel they are untouchable.

 

O nothing against them, just looking for something diferent or better. You also only see the FCRs on modded bikes where as you see a carb before cams on the DS's, just wondering why not put carbs on a Raptor before big bore and such.

 

Most everyone agree's that in stock form the DS head flows much better than the Raptors. SO it is a instant increase in power to add a good carb to the DS(thus taking advantage of whats already their). The Rappy is hindered by the head and cams,and not so much carbs. In theory, the twin carbs will give you more top end(as previously said).

You have probably heard DS guys say that they did'nt gain much with Piston and Cams,Or that a stage 1 was right with their stage 2 ro 3. this is because the stock set is aleady pretty good. And I am willing to bet that a stock Rappy will not see much improvement with just a carb upgrade,because the head and cams won't be able to flow the extra CFM. My.02


Biggerisbetter.