Quick/cheap performance mods??

Joined
Jun 11, 2002
Messages
310
Likes
0
#17
CANADIAN BACON said:
Jetting the Cr's is simple.
First go one size down on the main.
Next the air screw on these bikes is , I believe , two turns out.
If you need more than two turns go to the next smallest pilot.
If you need less than two go up one size.
Before you buy a pipe just try a Power core 2 on the stock pipe.
It will work and if it isn't enough it will still work on the pipe you buy.
I tried way more jets than that.............and finally got close. And no the other carb didn't fix my problem. The S4 nozzle really helps the 2002-2003 CR 250's........
 
Joined
Oct 24, 2007
Messages
4
Likes
0
#18
Needle Jet

I forgot to mention that when switching out the needle jets note that the "27" series needles are 1/2 position richer than the standard 26 series needles.
Jetting is a time consuming and frustrating activity.
However the Honda reliability is worth it.
The newer CR's have a smaller crankcase volume and are easier to tune. I'll find out soon as I have one on order .
The nice thing about these bikes.
If they aren't happy they just foul the plug and we know they come from the factory fat.
 
Joined
May 10, 2007
Messages
957
Likes
0
#19
you cant go with what he has. there is no PERFECT jetting for every condition cuz it is affected by temp. altitude, fuel, and what premix you use. and like a billion other things.

as for if you dont know how to do it.... it really isnt that hard. im sure you could find someone to help you do it the first time. thats what i did. i got my dad to help. now if i need to rejet i know how to do it.

also i believe sending the engine to eric gorr and having him port it for bottom end has good results for the money spent.

also getting your suspension set up is a great way to be faster.
 
Joined
Oct 24, 2007
Messages
4
Likes
0
#20
For Sure

flyingfuzzball said:
you cant go with what he has. there is no PERFECT jetting for every condition cuz it is affected by temp. altitude, fuel, and what premix you use. and like a billion other things.

as for if you dont know how to do it.... it really isnt that hard. im sure you could find someone to help you do it the first time. thats what i did. i got my dad to help. now if i need to rejet i know how to do it.

also i believe sending the engine to eric gorr and having him port it for bottom end has good results for the money spent.

also getting your suspension set up is a great way to be faster.
Porting is the way to go. Something you can also do your self.
On the vintage bikes we also cut the piston skirt on the intake side. Any serious 2 stroke rider will have their motor ported and polished.
However after all is said and done modern two stroke motors need constant jetting attention. If you don't like to jet buy a 4 stroke.
Once you get your main , needle and pilot sorted out adjustments can be made with the air screw.
Half a turn makes a big difference.
Good talking with you/all