Why this difference in power?

[javier1963]

Dear friends, this is my tecate that i ride ,it has a 1989 motor ,the reason for to put it here is i had installed in it a 1993 pipe , runs good but no awesome ,i want to put in it more power and i put a tecate pipe in it for experiment,i had to change the angle and to cut 10mm before cone in tecates pipe for adapt ,and now is other bike ,now i have problem for to put front wheel in land.If both of pipes are for kawasaki 250 motor and 1993 is from kx ,why is diference?silencer is the same for both pipes
Javier

[cr480r]

the tuned length probably works better with your particular port timing. You're lucky it performs well.. the changes could have just as easily hurt performance. Its nice to see guys trying new things and i'm glad it worked for you and it gives a nice factory appearance. I used a Fmf fatty for a '91-'94 kdx250 on mine, the cylinder and crank is '98KX250. Mine ran very well even with a severe mismatch at the spigot. I used to think the 2mm stroke difference between the engines had something to do with it, but then i found fmf sells the exact same part for the 92-93 KX250s.

[javier1963]

Congratulaton cr480r, i only dont understand it,original pipe for 93 kx 250 is made for to work in circuit with original cylinder ,my 89 kx 250 engine is standard no porting made in cylinder on the other hand i have more power with standard pipe for 1986 tecate, more logical will be more power with 93 pipe?
Javier

[cr480r]

well the '93 pipe is made for '92 and newer engine and wasnt correct for your engine in the first place. they have a different stroke than 87-91 engines. The shortened '86 pipe is probably more in sync with your porting than the '93 pipe was. You should try a '88-'89 Kx250 pipe sometime and see how it compares.

[javier1963]

thanks CR480R, I will go to made experiments w others pipes.
Javier