Hey guys. I was thinking of throwing a 440 kit in my sons 400ex. Can the stock carb be used with this kit if I jet it accordingly? I will do a bigger carb down the road, I just don't wont to mod it to quickly for him.

 

I wondered the same thing so when I started reading up on the subject I found that most people say that its not necessary and usually not worth the money unless you add big cams and port work. The dyno charts I saw that showed runs before and after carb change confirmed this theory. Now this was a couple years ago and maybe there is a carb available now that better suits a 440s power range but I have not heard of one.

 

We kept the same carb when we bumped my wifes EX up to 465.

I don't know if it hurt performance but Trinity had that thing jetted so well that it was easier to start than when it was stock.

 

Isn't the stock DS Carburetor a good upgrade on a 400ex? Buy the 440 kit, then get a 46hv or tm45 for your bike, slap the bsr42 on the 440 and you are good to go.

 

Chris, your killing me. How bout you donate the lectron, then I will.....haaaaaaaaaaa

 

I kept the stock carb on my 440.
With the stock 400ex and 13t drive sprocket I had to downshif into 2nd on comp hill, right side at Dumont. 440 bore, 13:1 piston, 13t drive sprocket, everything else stock. I can now pull the same hill at Dumont in 3rd.
I have been thinking about a carb as well but I don't think the BSR will work. It has the same throat size as the TM...right??. And I tried to see if the TM would fit and it wouldn't. Not unless I had someone make a specilal intake for it. What am I not seeing here Chris??? Are the TM and BSR diff throat sizes??? Guess I should dig out the bsr and see...humm

 

Craig,

If I donated the Lectron then I'd have to buy the parts for the stock carburetor that I lost - I couldn't possibly do that now could I? hahahah Besides, it is great having a spare stock carburetor for my 2001 just in case one of them gets messed up. (I just did a swap of them last weekend.)

Larry,

I don't know much about how the BSR42 lines up on a 400ex, however I heard that lots of guys with 400EXs were buying stock DS carbs and getting a nice CHEAP upgrade. Since you have a BSR42 in your garage, it seems like something you will HAVE to try!