best mod for speed?

[new400exrider]

i have a 2003 400ex, what would be the best mod for top speed thats around or under 150?

[MO-EX-RIDER]

16T sprocket?? its a cheap start!

[new400exrider]

ive heard that will make it hard to ride trails, but i guess i could switch back to stock when ill do that lol thanks

[new400exrider]

id still be able to use the stock chain right?

[jokester]

correct me if I'm wrong, but isn't the 16 tooth to big to be able to use with the case saver??

[ride_red666]

u could get a cam, airfilter or cdi for that much

[hornetgod13]

Originally posted by jokester
correct me if I'm wrong, but isn't the 16 tooth to big to be able to use with the case saver??

You're correct. I've read about people grinding and filing it to make it fit around the larger sprocket. Still others remove the case saver entirely.
I have not installed a 16 tooth sprocket but I imagine since stock is 14 or 15 from the factory you might have to add a link or two to the chain.

[Def-e-nition]

16 on a stock 39 or 38 would bog down the motor to such an extent he'd not want to ride like that for very long .

I would say a 15 , minus the trouble needed to grind the case saver , might be a better mod than going all out balls to the wall 16 tooth .

Hotcam - say no more . if you can get that in , forget sprockets and go for Power . You will not be Sorry .

[vett_09]

Originally posted by Def-e-nition
16 on a stock 39 or 38 would bog down the motor to such an extent he'd not want to ride like that for very long .

I would say a 15 , minus the trouble needed to grind the case saver , might be a better mod than going all out balls to the wall 16 tooth .

Hotcam - say no more . if you can get that in , forget sprockets and go for Power . You will not be Sorry .

On an 03, a 15T is stock. If he wanted to go up, he'd have to go to a 16. The larger front sprocket is a cheap. I paid less than $20 for mine. However, you will need a new chain. So plan on spending about $100 or a little more on that.

[Def-e-nition]

What size sprocket was on an 03 in front then ? if 15 T was front , then a 15 38 set-up would have been pretty tall . I'm running 14 -38 , and even that was too low for the 22's this weekend . 5th gear was like overdrive .

I notice you are running 16 T front , but you are also Running a 416 Kit , meaning you have the power to pull a 16 T sprocket .I doubt he will have the guts to pull a 16 T on a std engine .

So , regardless of how cheap front sprockets are , I'd still say a 15 t would be better .


http://www.renthal.com/front.asp


i found this very useful . In the end , I basically came to the conclusion that people tend to enjoy fiddling with front sprockets more , because it is easier to work with and is much easier to get to .

[vett_09]

Yeah, I forgot to add that. In order to get the most out of the taller gearing, you need a motor to pull it. Even with a high compression 416 kit, I'm not getting everything out of my larger front sproket. That's why a stage 2 hot cam and a new CDI box is going in after christmas.

[Def-e-nition]

Originally posted by vett_09
Yeah, I forgot to add that. In order to get the most out of the taller gearing, you need a motor to pull it. Even with a high compression 416 kit, I'm not getting everything out of my larger front sproket. That's why a stage 2 hot cam and a new CDI box is going in after christmas.


you lucky bugger ..

[new400exrider]

so i should just a get a cam and air filter?

[400exstud]

Originally posted by new400exrider
i have a 2003 400ex, what would be the best mod for top speed thats around or under 150?

I'm pretty sure that re-gearing is the ONLY mod that you will gain top speed from.

[FastestBlaster]

Originally posted by new400exrider
so i should just a get a cam and air filter?



air filters like 40$ and it helps so id say at leastly get that lol

[new400exrider]

how should i regear it then? i also plan to get a uni air filter