carb help!

[skrap1r0n]

ok heres the deal...my carbs are fubar...way fubar...to the point where the replacement pieces are discontinued. So a buddy of mine had some carbs he bought from another guy who said they were for an EX500.I do not have any idea what bike these carbs came from. I checked to see if they would fit and the keihin site said that the EX500 and GS 500 both will take the same carbs.

this set is a set of 4 Keihin carbs, kinda like this set. I am still trying to ID the exact carbs. The set is NOT on a rail, they are individual.

So anyway, I pulled out a V-stack and measured the opening and it's 43mm. I also measured the manifold side and it measured the same...43mm. The keihin site states that I can use up to 39mm for the 500's. it lists the same carbs size for both the EX and GS500. So theres the deal, I need help with a few things:

First, how do I ID the carbs? I have and see what they came off of
Second, did I measure right, if I did, how will a 43mm carb affect my bike. If I didn't measure them right, where do I take the measurement from?
Minor side note...this is going to be a trackbike only, so I will be using 100+ octane fuel in it.

[NiceGuysFinishLast]

Minor side note...this is going to be a trackbike only, so I will be using 100+ octane fuel in it.

Sorry I can't help with the actual carb issue, but the above statement caught my attention.

I have only one thing to say. Why? Are you gonna bore out the engine, and give it a higher compression ratio? If so, make sure you let us know how it goes, I love seeing stuff like that.

[skrap1r0n]

nope, not boring anything out. I go this set because he had them and he originally got them for an EX500 (I have an EX500 as well). I am not convinced these are 43mm carbs because I cannot find anything referencing 43mm carbs on the Keihin site, however,there are references on the we talking about 43mmcarbs, I may just call the keihin rep here in the US and see what they have to say. I will definitely keep you guys updated.

[NiceGuysFinishLast]

nope, not boring anything out. I go this set because he had them and he originally got them for an EX500 (I have an EX500 as well). I am not convinced these are 43mm carbs because I cannot find anything referencing 43mm carbs on the Keihin site, however,there are references on the we talking about 43mmcarbs, I may just call the keihin rep here in the US and see what they have to say. I will definitely keep you guys updated.

No no, I was asking why you're going to run 100+ octane gas in the GS. Unless you up your compression ratio considerably, there's no reason to run anything but regular old 87 octane, you'll be throwing money away. And if you've got money to just throw away, PM me for my address, and you can throw it at me instead! 

[skrap1r0n]

oh because thats the fuel we have for the track.

[Mandres]

oh because thats the fuel we have for the track.

well then take a gas can of regular with you unless you just want to pay through the nose for no benefit at all. 

[Wrecent_Wryder]

s3

[NiceGuysFinishLast]

oh because thats the fuel we have for the track.

well then take a gas can of regular with you unless you just want to pay through the nose for no benefit at all. 

+1  Think of all the money you could be spending on  instead of 100+ octane gas that does nothing good for your engine.

Sorry to have hijacked this thread so badly though, nobody seems to have chimed in with help on the carbs, they all responded to my question about your gas. You may want to start a new thread, and I promise not to screw the next one up.

[scratch]

I think the measurement for the carbs is at the venturi, not at the openings.

[skrap1r0n]

ok guys, this is a thread re: carbs, not my choice of fuel. Lets keep it on topic mmmkay? thanks.

[Mandres]

for what it's worth I picked up a good set of used carbs on e-bay for $70.  They came with a K&N lunchbox filter that I ended up selling for $30.  Let me know what parts you need; my old carbs are trashed and I might have doubles of the parts you're looking for.

-M

[skrap1r0n]

for what it's worth I picked up a good set of used carbs on e-bay for $70.  They came with a K&N lunchbox filter that I ended up selling for $30.  Let me know what parts you need; my old carbs are trashed and I might have doubles of the parts you're looking for.

-M

I need the butterfly valve and shaft. the one with the spring on it not sure what side, I'll find out tonight when I get home. As it turns out, as best as I can tell, these carbs I just got seem like they may be off a vulcan 1500 (yikes!) so I am not sure if they will work, lol. I am trying to verify this though. At the very least, if I can ID what they are off of I can sell them on ebay.

[Mandres]

for what it's worth I picked up a good set of used carbs on e-bay for $70.  They came with a K&N lunchbox filter that I ended up selling for $30.  Let me know what parts you need; my old carbs are trashed and I might have doubles of the parts you're looking for.

-M

I need the butterfly valve and shaft. the one with the spring on it not sure what side, I'll find out tonight when I get home. As it turns out, as best as I can tell, these carbs I just got seem like they may be off a vulcan 1500 (yikes!) so I am not sure if they will work, lol. I am trying to verify this though. At the very least, if I can ID what they are off of I can sell them on ebay.

Sry bud, I can't help you.  I actually replaced my carbs because I destroyed the butterfly plate trying to get it and the shaft out for cleaning.  There really should be a big sticker or something on the side of the carbs: "Don't touch the butterfly valve!"

-M