250 Carb Insulator

[Daniel P. McEntee]

I'm working on my '73 250H/S and attending to the Bing carb. I can not find mention of any kind of seal or insulator for the carb to intake manifold. There was none on the bike when I got it, and I can't find any mention of it in the manuals I have. I thought there was usually something to prevent cylinder heat from creeping up the the carb and boiling the fuel. The carb is a real nice fit on the manifold, so I'm assuming there is nothing? Looks like a recessed surface inside the clamp area for maybe an o-ring to help make a seal? I see no mention of that in the books either. Haven't turned anything up in a search, so thanks in advance for any help. I'm used to seeing something like this on my other bikes (Huskies and Hercules), and on my 125 6-Days.
  Type at you later,
  Dan McEntee

[chicagojerry]

hi dan. some of the carb/manifolds had them, some did not. if your carb fits snuggly onto the manifold and tightens up. you are fine. no o ring there either.    chi jer

[Daniel P. McEntee]

Thanks jerry. I've never had a bike that didn'thave something. The carb is snug, almost interfearence fit when first sliging it on, then gets a bit looser when it bottoms out. I think the intake manifold may be "hammered" from vibration over the years and may be a hair smaller as it gets closer to the engine. If tightens up, but takes a lot of torque to get it tight. I have some thin aluminum printing plate stock, about 4 or 5 thousands thick and will try to slip a shim between the carb and the manifold t help with the clamping pressure.
  Thanks alot for all the help you and the rst of the POG group has provided. Especially to you for giving me the heads up on the '73 pipe on eBay. I didn't think I would EVER find a stock pipe and wasn't really looking hard and wasn't too sure what I was going to do for a pipe. Looks pretty good, and judging from the few trips I took up and down the street last night, it works pretty good also!
   Thanks again,
   Dan McEntee