And here I thought that gabe was gone but he was only lurking waiting for the chance to chime in with his downing of the Yamaha product.

The accelerator pump on the 400ex is about as useless as the Raptors system for racing.

What is needed on BOTH the Raptor and 400ex FOR RACING is a Keinin 39mm flatside. Dual for the Raptor. Why would you need quicker pickup and fuel delivery for recreational riding?

Stay Away Gabe.

Spend your time looking for front shocks and a new and longer swingarm. I have a feeling you will need them. Man I love my Raptor.

 

hey 2001 raptorrules, i assure you that gage can give you a good a** wooping ethier on mx track or in the woods, on his slow 400ex. the smaller fcr's would be the way to go. with out using pumper carbs the swap would be a waste of money. no trottle response, you think the raptor sneaze off idle now use a non cv or pumper carb and see what happens.

 

Excuse me but who was going to race. And you know nothing about how I can race Anyway. To say such shows an argumentative and thoughtless reply.

I can say this; we do not race in the same circles.

By the way, I think my *** would be fine in a race anywhere with a stock 400.

I do not attack "gage" personally, I do not know him, only his intent on this forum. Please read my reply more thoroughly.

 

So why not just put 2 big@ss CV carbs on it. I dont care, just so they are bigger and they are 2 that work. Seriously I think I will just have the stock ones bored out first, then later pay for new ones.

 

I have been reading this excellent 4 stroke tuners book and they mentioned the first thing to do when building a high perfromance engine that has CV carburetors is to remove them and go to a convention flat slide carburator.

The reason is because they just do not flow very well at high rpm and they are difficult to get jets and needles to tune them properly.

The book also said that the most common mistake is to over carburate. You should go down in carb bore by about 4mm from the CV carb size.

 

Exactly!

 

So its as easy as putting on flatslide 28-32mm carbs? that should be cheaper atleast.

 

The only problem(from what I hear from Carb Parts Warehouse) is that Keihin is making a kit for the Raptor but it will be a 35mm kit.

This is doing exactly what I had heard was the incorrect thing to do, but, I think anything will be better than the stock CV's.

 

Why even bother with dual carbs, they have a lot of disadvantages, such as:

Double the cost.
Stiff throttle pull (CV carbs cure this on the Raptor, but present their own problems).
Difficult to tune, must do everything twice.
Feeding 1 valve with one carb and 2 valves with another is just asking for trouble & inconsistencies.

Something like a 41 or 42 pumper should feed a stock (and probably even a lightly modified) engine just fine.

Surely someone will offer an intake & airbox setup for this soon if it's not already available....

 

The problem I see with the single carb set-up is an air/fuel flow nightmare. Problems I see with this:

1. The dual valve side needs more air/fuel than the single valve side.

2. The single carb would feed into a one-into-two boot. But that boot would have to divide the air/fuel in an uneven porportion.

3. Turbulence problems aside the vacuum from the two valve side would be greater than the single valve side and create more problems.

This was tried on the Banshee, I believe, without much success.

Blue Raptor
TCS Shocks, LoneStar A-Arms +3, Durablue Axle +5, Big Gun Header, GYTR Silencer, Renthal Bar, Fastline Brake Lines, DG Bumper