BannedCR500Riders.com

can we run the 250 carby on the 500 motor.
im hoping to do so and maybe a re-jet.

any thoughts people.

The 99-00 is a PWK airstriker, so you shouldn't have any problems because it's a common carb. Any other year, you are on your own. I think the 250 changed carbs yearly.

Yeah I have 98 CR 250 carb which is a PJ 27,my other 500 one is a PJ 28,but they have the same diameter so Id like to know the same thing. Can anyone help ? Cheers

Hey Juddy,
any good porting and polishing mobs out your way

Never really looked into it myself.Can ask around Perth area if you like though. I do have the phone number of the guy who has built 11 winning Finke engines though.He is in Victoria. If you want to talk to him I will be home on the weekend and can get his number.

asteroid500 wrote:can we run the 250 carby on the 500 motor.
im hoping to do so and maybe a re-jet.

any thoughts people.

If you are going to use the PJ off of the CR250 you just need to use a 38mm and set your float level the same as the 500, use the right jets, needle, slide and idle settings to suit the engine you have.
You are now good to go.
I am told they are the exact same casting.

asteroid500 wrote:can we run the 250 carby on the 500 motor.
im hoping to do so and maybe a re-jet.

any thoughts people.

hi im using the 38 mikuni tps 250 carb they used on the last of the 2stroke honda 250 and i even had to lean it out a little and the bike is perfect it idiles no bogging and revs out fully i used it with all the wiring connected to the 250 ignition its perfect

Craigf40,

That's interesting!

With nearly everything written about the later model CR250s with the Mikuni's, one of the main things you'd see was people/ performance tuners hoiking the Mikuni for PWK Keihins,then claiming most of their erratic jetting and plug fouling problems were gone.

As you've had no problems (and with the whole 250 ignition set up with the TPS , which I'd think would be a great thing ,by they way) , I guess it was a combination of a whole group of things that made the 250s a pain in the arse.

So, very interesting results for you. I've a mate with a stationary 06/07 250 who's trying to find a 500 engine, which I'll then do a conversion on. I might snaffle his carb and ignition for a while later in the year. Leaning out is common with open classers/ bigger engines, modified engines, as the 'signal 'delivered to the carb is so much stronger - in simple terms, the bigger engine sucks so much harder, more fuel is drawn through the jets.

I cannt sayyy for sure its all systems go...BUT,
Danny and Mick both ran or run this ingnition at apoint of time on there G-1's with very good results and i hold there opinions very highly because they back there shit up with seat of the pants POV.

mine aint running yet but when it is you'll all know.