Need more top speed

[quadrider400ex]

What sprocket do I have to change to get more top speed? I ride mostly open area and would like more top speed.

[smorris1]

Smaller rear or bigger front. Changing the front sprocket will give a more drastic and noticeable change.

[quadrider400ex]

ok thanks. I'll probably go with a bigger front. Have any recommendations on which bigger front sprocket to go with (size)?

[KKiowaTJ]

One tooth on the front is the same as changing 3 teeth on the rear. Go to ebay and buy a couple cheap ones until you find the combo you like.

[ish416]

A 16 is the biggest I could fit. Also, you will need to remove your case saver as it will likely hit against the chain with the larger sprocket.

Also, to pull a 16 front you are going to need some extra ponies. A stock EX has a hard enough time hitting the limiter in dirt.

If you dont have at least the basic bolt ons, exhaust, intake and rejet then dont waste your time as you will not be able to pull the gearing and will probably end up with a slower quad.

If you can pull the gearing expect about a 4-5 mph gain.

[quadrider400ex]

Originally posted by ish416
A 16 is the biggest I could fit. Also, you will need to remove your case saver as it will likely hit against the chain with the larger sprocket.

Also, to pull a 16 front you are going to need some extra ponies. A stock EX has a hard enough time hitting the limiter in dirt.

If you dont have at least the basic bolt ons, exhaust, intake and rejet then dont waste your time as you will not be able to pull the gearing and will probably end up with a slower quad.

If you can pull the gearing expect about a 4-5 mph gain.

How many teeth are on the stock front sprocket? And I have an aftermarket exhaust and intake (everything is in my signature), just need to get the quad jetted. I really just want to get a little more speed out of each gear.

[ish416]

Stock gearing for the 99-04 is 15/38 and 14/39 for the 05+. The 05's had slightly revised internal gear ratios also but were still geared lower than the earlier models.

If you have an intake and exhaust then you have to rejet your quad. Otherwise, you risk causing damage to the engine by running it lean.

[JOHNDOE83]

Really without power mods youll have a hard time pulling top speed out of a 16t front sproket.

I have a 440 with cam, valves and a bigger carb with 22in tires and 16/39 gearing and I can get 70mph out of 4th gear with no issues, havent had a chance to get a 5th gear top speed yet.

[Drfat400ex]

You'll have to check but I'm pretty sure you can't go any bigger than 15 on the front with an 05+ 400ex. That's what the dealer told me anyways.

[Stickman400]

Yea, I'm pretty sure you're right. I have a 15 tooth front on my '05 and even if you removed the case saver you would be hard pressed to get a 16 tooth in there. It either wouldn't fit period, or it would rub the chain on the case, which wouldn't be good.

OP you're probably gunna end up having to go with 15/36 gearing and then 22s in the back if you want to get all you can out of it.

[quadrider400ex]

I'm gonna order a 15 tooth front sprocket and see what it does for me and then I'll go on from there.

Thanks for everyones advice

[thebig450es]

on the dyno i hit 80mph with the 16t/38/20, im going to try 16/33/20, i should be near 90mph

[JOHNDOE83]

Originally posted by thebig450es
on the dyno i hit 80mph with the 16t/38/20, im going to try 16/33/20, i should be near 90mph

Throw some 22in duro scorchers on there and I bet your EX can easily hit 95mph!

What did your EX hp hit on the dyno?

[thebig450es]

40hp at the wheels, stock on that dyno is somewhere at 21hp