Carb ID question...

I picked up a rack of carbs for parts from Ebay to get some replacement parts for mine. They were listed as carbs from an XJ650, but there are some significant differences from my carbs (and I thought all the Hitachis were the same except for jets). My question, basically, is if anyone knows if there were different models of the Hitachi carbs used on different years/models of XJ's. It looks like most of the parts I need will interchange, but I'd like to know what I have here.

First of all, they're definitely Hitachis. They look just like my HSC32's, and the fuel jets are correct for the 650, I believe (110/40?). The float bowls seem to come from a different casting, as the external shape is slightly different, but internally they look the same and they seem to mate up fine with my carb bodies.

The biggest difference I've found so far was that the mixture screws have a completely different threading than mine - Although they're the same size, the threads are much coarser. If I had to estimate, I'd guess they're maybe half the pitch of my screws. (That was a letdown, btw - I pulled out a complete set of mixture screws that looked brand-new, only to find that I can't use 'em. Oh well, at least mine are still functional.)

Anyone know what I've got here?

 

As far as I know, ALL Hitachi HSC32 and HSC33 carbs use the same idle mixture screws (and thus thread pitch). There is a difference in the bowls though, some bowls have dual drain-screw outlets (although only one outlet is threaded on such bowls; the other is blocked off internally) and the other style bowl only has a single outlet. Either style will work. If I recall the single-outlet bowls were used on the HSC33 style carbs (85-6 &00 non-X models).

Maybe someone re-cut the bores in those carbs to accept some other brand of mixture screw? Were the screws steel or brass?

 

pictures would really help here.

 

That's what I thought. I'm wondering if they weren't maybe mis-identified. Hitachi must have made carbs for other bikes too, right? They'd probably reuse the same design instead of redesigning the entire rack, I'd imagine. As I said, most of the parts I've tried have interchanged just fine...

This one has the dual outlet, but the shape of the "well" that the pilot fuel tube dips into is different on the outside of the bowl. Not on the inside, though.

That's certainly a possibility. Looking at them now, I'm noticing that the shaft is a slightly different shape (not at the needles, but where my screw starts to taper, these are stepped). They look to be the same material. Heck, the special screwdriver I bought from you fits them perfectly.

PghXJ: I know, wouldn't they? :? Unfortunately my wife went out of town and took the camera with her... I'll post up pictures when she gets back though.

Seriously, I got lucky, because most of the parts I needed were intact - but the rest need to be seen to be believed. (Fr' example:The first bowl I opened up, there was nothing in it except for two loose pieces of float material and a small mountain of powdered rust that used to be the float hinge and pin. I'm talking completely disintegrated.) They were so cheap, I wasn't expecting much, but day-umm...

 

My guess is that a PO couldn't find the Hitachi mixture screws and retapped for a set of Mikuni mixture screws.