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JHF219
08-10-2004, 11:50 AM
ok guys im needing some input here on what i need to do. im getting my *** handed to me off the gate and its getting really old not being able to pass on a one line track if i dont get out front.

Here is my list of mods so i need suggestions on what to do next.
86 250R motor
66.75mm piston
Pro Circuit Pipe
stock carb
Open air box with K and N
using 160 main jet
Ported and polished cylinder
13/38 gearing
Holeshot MXRs all the way around

It seems like NO MATTER what i do i cannot grab a holeshot and its really starting to piss me off please add input. I want to keep this cheap and i dont want to go boring the motor(im afraid of losing reliability) and i DONT HAVE THE MONEY FOR A PV :(

wilkin250r
08-10-2004, 02:11 PM
Your cylinder is ported? Where did you get it ported?

Are you running the stock cylinder head? If so, did you get any head modifications when you got your cylinder ported?

JHF219
08-10-2004, 02:39 PM
Originally posted by wilkin250r
Your cylinder is ported? Where did you get it ported?

Are you running the stock cylinder head? If so, did you get any head modifications when you got your cylinder ported?

I had a local port the cylinder(he is well known for automotive porting)

Im running the stock cylinder head, no there are not any modifications ?

Snow
08-10-2004, 02:48 PM
get a bigger carb

wilkin250r
08-11-2004, 05:53 PM
A bigger carb will help a little bit. I think you would see major gains with a new head, or modify your existing head.

In a 4-stroke, you can get a higher compression piston. In a 2-stroke, you get a higher compression head. There are several companies, NOSS, Pro Design Cool Head, Duncan Racing Powerhead, and I think ESR even has a head designed for the stock cylinder.

Personally, I'd recommend an aftermarket head, but you can also modify the stock head to increase compression. You may have to make the jump to race gas, but the gains are well worth it.

If you had to choose between the two, I'd certainly go with higher compression over a bigger carb.

ESR250R
08-12-2004, 05:25 PM
if you only have a 160 main, thats telling me that you dont have much porting done. i have a 185 in my lrd ported/polished cylinder (38mm carb though). i would recommend getting you cylinder ported buy someone that knows what there doing, bumping up your compression with either a new head or have your stock head milled down, then maybe a bigger carb. if your running 18" rear tires i would recommend that you move your gearing to a 14/38 for MX. then work on your 2nd gear launches. thats my setup and its extremely reliable, i have about 20 races on the same piston and rings.

lil400exman
08-13-2004, 09:17 AM
JHF-check your pm's!;)

seth400
08-27-2004, 12:31 PM
go with a bigger carb, 38 or 39mm airstryker you will not regret it

jokerman_28
08-28-2004, 12:35 PM
yea, get a airstryker carb and a head. pro designs cool head are a good choice. they have interchangable domes. so you can switch from race gas to pump gas. or even get one that runs half/half. the carb is about 200$ and the head is around 180$ you wont regret either of them.

exboy400
09-05-2004, 04:18 PM
if you wanna put out the money for race gas then just use a thin head gasket, get some reeds, a 38 airstryker is what i run and get it ported by a pro....i think that will do wonders

Jpoutlaw250R
09-12-2004, 12:25 PM
What year chassis do u got? maybe getting a shorter mx swingarm if u don't got one will help on the hookup and holeshot.

marksuttonjr
09-12-2004, 05:12 PM
Here are a few optins that should stay reliable & won't cost too much $$
better reeds
mill head
thiner head gasket
CR style piston
lighten the flywheel
play with the gearing a little
lowering strut to move the center of gravity more to the rear so i hooks up better


a few slightly more costly mods
larger carb
better porting
or replace the head
better pipe
shorter swinger so it hooks up better


My quad is just a woods bike, but here is my current setup
Sparks MX pipe & silencer
long rod crank
68mm cr style piston
factory 89 head milled .005
85 ATC cylender with the ports polished out but verrrrrry little resizing of the ports
customized 4mm cylender spacer spacer plate (was a normal 5mm spacer plate but had some nasty gouges in it after I let a friend clean the old gaskets off)
1/4" reed spacer
Boysen RAD valve
36mm KEIHIN carb carb says "RACE USE ONLY" but it works well for me just woods riding
168 main 58 pilot
the inside of the crankcase has been slightly enlarged and hand polished to nearly a mirror finish
86 transmision
14/38 gearing
18" rear rubber

900rracer
09-12-2004, 06:29 PM
I always had terrible starts with my 250R now I run a new 450R and I am pulling good holeshots. I only raced it twice this year at Steel City MX one race I took second on the holeshot and the other I took the first turn it was all me.
What technique are you using on starts--first or second gear? I am sure most people use second, but I just had to ask. Are you watching the gate or the pin that drops the gate. I had another racer tell me to watch the pin that holds up the gate. When you see the pin start to drop--hit it, by the time you get your wheels turning the gate will be down. Watching the pin helped me a lot.

Kevin Stover
ATVA District 5
Quad B #227

89 250R
04 450R

marksuttonjr
09-15-2004, 08:18 PM
I should have posted this in my previous post

If you are not already a member go over to RRiders.com and join. It's the best 250R website on the net