WTF Jets gah foo

[xwhatsit]

I have two carbs -- one on my bike, that is clearly useless (or perhaps it's some other problem, like a manifold, or perhaps (yay!) a cracked head). At any rate it's very lean. The other carb I have was in the box of bits along with the parts bike I purchased. Bike in question is the very lovely CB250RS.

It is a Keihin PD70A. This is a strange creature; I can find very little about it mentioned anywhere, and as you will see it seems slightly irregular.

I purchased one of those nifty little Keyster carb rebuild kits, with a view to rebuilding the spare carb. However, they don't make one for the CB250RS (not an American model), so I got one for the XR250 instead. In the pictures the gaskets looked identical, and the slow jet was the same size (at least if the slow jet is the same thing as the pilot jet, which now I suspect it is not). I asked the guy if he'd do a 122 main jet instead of the supplied 115 main jet (122 is standard for my bike) and he did this.

Anyway, I open up the spare carb, I open up the kit, and there seems a hell of a lot more brass bits than there are in my carb. Most disturbingly, the main jet is completely different. The old one is a little ~8mm screw type thing (looks like the first picture), whereas the one supplied is a big hex bastard that looks like the second picture. It fits into the needle jet, but sadly is too long for the float bowl.

This is ghey, because on the Keihin website it reckons PD carbs have the big hex bastards.

Also, there's the idle mixture screw. These are the same between the two carbs. However, my pilot/slow jet (#40) in the carb is just a round tube pressed into the body, whereas the one supplied has got a thread and a place to put a screwdriver, and also holes along it like it's a mini needle jet. There's also some bizarre little piss-arse jet-like thing as well, with no threads or whatever. According to the carb kit, I have a NEEDLE VALVE; JET, NEEDLE; and NEEDLE JET. Wtf, mate.

I'm feeling very pissed. Possibly pissed off, too.

Where do you guys buy Keihin jets?

[Kickaha]

Where do you guys buy Keihin jets?

Any bike shop, should be able to source them, take a sample.

[xwhatsit]

Any bike shop, should be able to source them, take a sample.

Awesomeness.

[xwhatsit]

Super, Henderson Motorcycles got me a 125 main jet. Bigger than the standard 122, but rich on the main jet is better than too lean. I rarely, if ever, use full throttle anyway.