1989 cr250 carb PJ38 flat side

[Paul552]

This model carb has the idle adjustment on the choke knob.
Mine is busted (plastic nut) and corner of slide is a bit warn.
Anyway I got to buy a new choke plunger and probably a slide wouldn't hurt.
Got me thinking can you buy a new carby still? Or after reading the thread on the 480 carb upgrade I was not sure if it is worth fitting a different one?

Is there a good upgrade for the 89 cr 250?

[Nathan S]

I hate PJs. Every time I get one that works ok and I begin to forgive them, I get a shitty one that reminds me why I hate them.

They are basically a road race carb. They make good power, but don't idle reliably, and are damn near impossible to jet cleanly off the bottom, due to their lousy vacuum signal to the pilot.

Put it in the bin, and fit a PWK. It will go straight in, but MUCH easier to jet, will smooth the bottom end power, and the thing will idle well. You'll also find there's a deeper knowledge pool for jetting (particularly needles).

[Paul552]

Thanks Nathan

How much are the PWK??
Can you buy them locally??

I think the parts I need for the PJ will be about 100 bucks so the gap to the upgrade maybe worth it?

[Nathan S]

They came on KX250s and 500s from 1988 to the late 90s (maybe later?). Lots of KTMs from the mid-90s too.
YZ250 from 95. RM250 around the same time.

There's a couple of variations - most notably the "airstriker" that first appeared in the mid 90s, and the electronic power jet first appeared in 97(?), and TPS in around 99 or 00.
The airstriker is a small but worthwhile improvement, the TPS and power jet are only useful if you have an ignition that can use them.

[evo550]

What Nathan said.
The best is the PWK air striker without all the fancy bits.
The new PWK on modern Kato's are a pain to jet and extremely sensitive to changes in atmospheric conditions.