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View Full Version : big red performance ideas. I like to work with what I have.



conig
08-25-2004, 05:42 PM
On my quest to modify and restore my Big Red I want to replace some of the engine parts. I am thinking 1. a cam for a 250sx, unless one for a trx250r will fit as they have a more aggresive cam. 2. a new carburator can anyone advise what would be a good carb? I am thinking the one listed below but am not positive it will work. Can someone give me jet suggestions I should look for. Will this carb only work with a fuel pump?this one. (http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=1650&store=Main&productId=p1650&catId=111&leafCatId=11101) they multiple kinds I assume I need a spiket mounting style. what size is the stock carb? 3. to redo my exhaust as the muffler has holes in it. does anybody know if the cobra exhausts kit utilizes a large header ? If not my stock one is in great condition and I assume to just use it. I will get a universal muffler FMF Super trapp etc.

I know my big red is not a sport atc but fits my riding style pretty well, plus I like to work with what I have. A bit more pep and this will be more then suffieceint for some time.


I also want to get new rear tires and am thinking a 22 or 23 inch tall tire for the rear. If need be since mine are kinda rusted I would get some new rims as well.

TTribaLL
08-25-2004, 06:12 PM
I think you should just keep it stock.

conig
08-25-2004, 06:50 PM
I agree with you to a point but can't afford another four or three wheeler I like. this is the reason you see me concentrating on bolt ons and not jumping into the engine. I don't want to put anything on I can't remove in a weeks time. As soon as I attain something else I will quazy retire this one.

I wish I knew more about carborated motors. and this would be easier.

MTS
08-25-2004, 07:09 PM
i dont think a trx cam will fit seein as the trx..least the old ones are 2 stokes..corret me if im wrong XD but a 200x cam would suffice i thinl unless your big red is a 250 :D

ClayW
08-25-2004, 07:14 PM
If im not mistaken, actually im pretty certain, that the SX and ES camshaft are identical. The only difference in the ES motor and the SX motor are the Tranny gears. The SX's are a bit taller, giving it more top end. Everything else is the same.

ClayW

almac16
08-25-2004, 07:57 PM
If im not mistaken, actually im pretty certain, that the SX and ES camshaft are identical. The only difference in the ES motor and the SX motor are the Tranny gears. The SX's are a bit taller, giving it more top end. Everything else is the same.

ClayW


No, the crank on the SX is bigger! Not sure what that would do for performace but I would't suggest swapping for the bigger one if you didn't need to.

Also here's the thread where we discussed this already
http://www.3wheelerworldforums.com/showthread.php?t=23242

there is also talk about the rocker arms and gearing

83185s
08-25-2004, 10:48 PM
id say first get a dial a jet and a snorkle kit for it about $100..then get a webcam $112..and a k&n filter..bigger front sprocket and smaller back if u want it to go faster..thatll cost about 30-60 depending on the brand..and a dg,cobra,jardine or some other kind of exhaust for it...trailprotrailpro look at about $350-$450 for wat i just mentioned....help any???

conig
08-26-2004, 10:38 AM
every response has been of help.

im surprised no one feels the carb is worth it. exhaust is the first think on my list and I have a moose aire cleaner in the stock air box 2days old. I may go snorkel setup when I get more time to figure the setup out. Or open element if I can keep myself out of the mud.

I knew the came was the same for the sx, but I found not an sx cam but an after market weber replacement for the sx that adds power across the entire rev range.

I thought the gears were the same If I can find a set of these this would be my next investm,ent after exhaust.

I'm checking out that link now, I searched but don't think I saw it.

conig
08-26-2004, 10:52 AM
anyone know if the headpipe is larger on the cobra exhaust? also does it have baffles?

and last what size is the stock exhaust head pipe.