Carburetor

[Mark Yacavone]

Does anyone know, specifically, what the differences are between the late 70's/ early 80's carbs and the late 80's, 90's? Please, specifics. No conjecture.

Thanks

[T-dub13]

Be more specific as to the model of bike the carb is you're referring to and you might get answers.

[Mark Yacavone]

Sorry, you're right . Forgot this wasn't a specific XR 80 section.

The bike is a 1982 XR 80.

Thanks

[Mark Yacavone]

Then again, maybe not, Tdub?

[socalxr]

The other problem with post is you said, "No conjecture." Unfortunately, we're all pretty much full of conjecture. ?

As far as I know they are all the same. I've pull off original carbs and compared them to new carbs and they appear to exactly the same. They may have slightly different jetting, but I usually always re-jet anyway, so to me that's not a factor. I do have a psycho-anal friend who talks about the float level going from 19.5mm to 19.4mm (or whatever), but every new carb I ever put on ran perfect, with minor jetting changes.

Also, what applicable info are you looking for? Are you doing a full restore so it has to exact or are you just putting an old bike together to get it to run right?

If your putting an old bike back together and it's popping and running like crap, it's usual the carb or the ignition. You'll save yourself a ton of headaches if you get a new carb and convert to a CDI ignition. ?

[Mark Yacavone]

Thanks for the reply. That's kinda what I was looking for. Someone who actually has compared the different year carbs. I figured the jetting was probably different in the later years. From the pictures on Ebay that I've seen, they all look the same.

No resto, just a pit bike. I'm just trying to get it to idle. It acts like a vacuum leak, but it's not. Yes, I took the carb apart ( about 9 times). The pilot jet and idle system looks fine. I thought I'd just try a different carb at this point.

I doubt that I'll put a CD ignition on it. I only paid $300 for the whole bike . The last one I had , had points and it ran fine for 15 years. I did order a coil though. The one on it is not correct and it won't fit up under the tank where it belongs.

Mark

[T-dub13]

Lookie here ?

[Mark Yacavone]

Thanks, I've seen this thread before. I had the advancer off and it appear to be like new. Once it returns to base timing, it should have an idle speed of some kind. Not so with mine. Same if the throttle cable or slide sticks which it doesn't, it should return to a set idle.

I did notice that after I took it around the block the other day, that the idle was real high afterwards, then it eventually went down to where it stalled. Maybe the plug got cleaned off and then it loaded up again. I'm leaning towards the coil now, seeing that the plug it always black and sooted up . Once I replace it, we'll know what it was (or maybe what it wasn't)