Interchangable carb parts? '84 and '85 VF500

http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWA:IT&viewitem=&item=200198587591&rd=1

Just bought the above on ebay. I figure even if parts aren't interchangeable, I'll just take them apart to learn about their various nuances before I break mine down if the need ever be. So anyone know if any parts are interchangeable? I don't know if my bike is a CA model or not; I heard you can check with the VIN#, but I don't know what range signifies CA model.

BTW, if anyone needs a part/parts from these carbs, let me know, provided it isn't something I'm going to use you can have it for whatever it costs to ship.

Below is the the carb info section from my service manaul that shows what model carb is on what year/model/49-CA interceptor. So far as I can tell the only difference is the main jet numbers between 84/85?

 

Hey, VFRide. Just thought I would comment on the jetting for an "FYI" contribution (lucky you!). The 102's are smaller, so the two front cylinders are running leaner than the rear two. This was/is a typical tuning trick for inline 4 cylinder air-cooled engines, known as "stagger jetting". The two center cylinders would be jetted slightly richer because they run at a higher temperature than the outer cylinders. I've never seen that on a liquid-cooled engine, but it could be that the '85 had a slightly revised cooling scheme that made the staggering unnecessary. With regard to interchangeability, I haven't a clue. Me, I would use a magnifying glass and a set of calipers to compare the parts I was contemplating exchanging.

BTW, is this another chapter of the creeping idle speed issue you were having?

 

Is it related to my idle problem? Not directly, oldbikebarn still hasn't got my new air filter to me (it's been 1.5 weeks now)l; and I don't want to have to remove the tank twice, it'll just be easier to take care of filter replacement and leak/lean diagnostic all at once. I also figure 5 dollars for a set of carbs is a steal, I was hoping to break them down to learn on them without risking ruining my actual ones; I'm not messing with the jets. In any event, if I find anything broken/worn on my carbs, if parts like the diaphragm/float are interchangeable, I'll just have saved a bunch of time and money.

I swear sometimes I can HEAR the air leak, but I still can't find it and it's not on the carb boots. I read the plugs and can tell the left side cylinders are the only ones affected; white insulators. I would think only leaks after the butterfly valve would induce a lean condition; but right after the valve are the carb boots. :frusty:

 

Forgive my poor memory, but have you checked your valve clearances?

Five bucks IS a steal! Carbs really are straightforward in operation; it is usually all the trickery thrown on top of them that can be a genuine pain to diagnose problem on. And before I forget, I have used Armor-All on old slide diaphragms to extend there lives. Old heat-cycled rubber is, well, old heat-cycled rubber. Have fun!

 

No, I haven't checked my valve clearances, the process for performing the check and adjustment is pretty well, daunting to me, I'm used to small two strokes only. My service manual specs every 8k for a valve check, mine's at almost 15k now and I don't have any service records from the previous owner; it's overdue.

In all honesty I think for this bike I'm just going to run it until it something breaks on it that isn't a ready made fix; the whole reason I bought it was to be a learning bike. The idea saddens me a little because I'm attached to it, but the lack of readily available parts is rather unsettling.

But as for the carbs, the set I bought is missing the no. 1 carb, but still a good deal IMO.

 

Well, I do understand that. If you go through the carbs and they don't seem too difficult, checking valve clearances is more work, but not too technically difficult. Granted, there is a lot of stuff to remove, keep track of, and replace. I mentioned it because carburetors rely on pressure differential to work properly, and valves that are out of adjustment can cause some real issues with the pressure "signals" that the carburetor responds to. Temperature also affects the influences, since the clearances change.

Darn, I do wished I lived closer or knew VF500 fuel systems. It seems bizarre that both left cylinders are lean, unless there is a common vacuum junction that is leaking, or a common fuel feed that is problematic. Sorry I have nothing more constructive to add.

 

Hmm, you do bring up an interesting point. When the engine heats up past the middle zone when sitting still for a while, it has a hard time staying on (I have to choke it or keep the throttle applied). Since you said the valve clearance changes as temperature rises, my engine over revving at idle with no choke at normal operating temp and struggling to stay on at higher temps would seem to coincide with the symptoms you suggested.

My other theory, that I mentioned in another thread, is that the previous owner messed with the pilot settings; the plugs that need to be removed to make pilot adjustments were gone, indicating that they aren't factory settings.