250r modification question????

[BigGreenMachine]

Ok well you should have wasted that 400EX in the sand.

[OldSchoolin86]

It's probably just tired. HAve you done a compression test yet? WHat kind of pipe are you running? I bet all you need is a fresh bore, a nice exhuast and a little shave on the head.

[chromedout]

I don't know whats wrong, when we first got it, my wife drove next to me in the truck and I got up to 86 mph. I though that was good, and surely a 400x can't do that. But from what i see it's all stock. Just bought it and haven't done nothing to it yet...but I'm going to know...

[OldSchoolin86]

Maybe the 400ex was worked over pretty good? It's not hard at all to pull 40+ hp out of them.

EDIT: 86 mph? What gearing are you running?

[travis712]

I know its kinda a dumb question, but you both had paddles right?

But unless the guy weighed negative pounds, i don't see how you didn't walk away from him in a drag.

[ChrisD]

If you were doing 86, you may be geared for top end. You should probably look for 14 / 39 gearing if your bike is stock and 14 36 if its modded. If you're geared too tall, you will not get full power out of the bike. The sand is a HUGE drag on the bike and motor. I don't see how you would lose to a 400ex.

Since you have an 86, this is what I would do

ESR310 or 330 motor (comes ported with head and domes) It's big enough to give you power without having to stroke the crank
Keihin 39PWK
K&N
Reeds (you choose...boyesen or other brand)
PT Hi Rev pipe and Fat Boy 2 Silencer
14 / 36 gears.


That should be a pretty reliable set up for the dunes.

[CHARDOG]

DUDE.......ARE YOU SURE IT'S A 250R??? THE PIC IS A 350X!

[Dammit!]

Here's what has been done to mine.

Ported by PR Racing
RAD Valve
38mm PWK carb (52 pilot, 178 main)
FMF Fatty (gold series)
Heavy duty clutch
K&N air filter with no airbox lid

I think PR Racing sprinkled some magic Go Fast dust on it or something. It seems to be faster than the sum of it's parts. If I could just keep the front end down I would very rarely lose a drag race on it. I'm not sure if the head has been milled or not. I am still running a stock three layer head gasket though. I'm gonna be putting a Paul Turner High Rev back on there (that's what it had when the motor was built) and I need to get some good lightweight paddles and an extended swingarm. I think that will put it right about where I want it.

I used to want a ESR top end but I think I'll hold off until I get beat by one.

[travis712]

DUDE.......ARE YOU SURE IT'S A 250R??? THE PIC IS A 350X!

it says he has a 350x n 250R.

[daputz]

It's probably just tired. HAve you done a compression test yet? WHat kind of pipe are you running? I bet all you need is a fresh bore, a nice exhuast and a little shave on the head.

I think Oldschoolin nailed it Wait to add performance parts untill you get a good overall condition on the engine. Also find out what gearing you have to hit 86 mph. You might want to adjust the gearing a bit to get a better pull instead of all top speed.

[chromedout]

I think its all stock. We were doing 86 on pavement. I couldn't hit six gear in the sand. And yes it is a 250r, I also have a 350x. And yes, the 250r had paddles on it when i went to the dunes.

[chromedout]

so whats the cheapest way to fix her up quick. just to see if shes got the power.

[thefox]

so whats the cheapest way to fix her up quick. just to see if shes got the power.

Compression check and count the # of teeth on each sprocket.

[OldSchoolin86]

Compression check and count the # of teeth on each sprocket.

Exactly, you have to know where you are before you know where you're going..........