CR Carbs 33mm to GS1000SN 26mm ports

[rollfast]

Here's the problem. My original SN carbs were beyond re-build, eaten up internally. I picked up a rack of 26mm VMs at a swap meet from a Kawasaki 900, same carbs as GS1000, minor difference in linkage. I cleaned them and re-jetted to match the stock GS specs although there are some modifications, i. e., K & N filters, Jardine 4 into 1 exhaust, Lucas-Rita electronic ignition, Dyna coils. The engine starts easily, idles well but as you crack the throttle it goes flat, does not carburate correctly, and I think the problem is in the rubber joints although the "Gum Out' test did not indicate that they were drawing air. I still have my doubts.
Meanwhile I have a set of brand new Keihin CRs that are way too big, 33mm. Since I am going to have to buy new joints anyway, I'm thinking that somewhere, perhaps snowmobile country, there is an adapter that will solve this problem. Sudco cannot help, I tried. (Yeah, I know the 1980 head with the larger ports might be a fix- if I had one- but that involves a major tear-down, and I don't want to go there until there is a mechanical problem that justifies the expense.)

 

[hampshirehog]

If you set your new carbs up to the standard specs and are running pods and a 4-1 she'll run like poo on anything other than tickover. Plenty of info on here - do a search for GS1000 jetting and you'll see what settings folk are running their bikes on.

 

[rollfast]

Hi
I neglected to mention that I ran the motor with the stock set-up prior to the mods. It ran like a three-legged dog just the same.
The bike had sat outside and neglected since 1986. Miraculously the motor was not stuck despite the long inactivity. The former owner told me that it had a charging problem which I correctly assumed to be the alternator stator which I soon replaced.
The carburetors were beyond human help; I have never seen worse. The fuel tank looked like a collander with latex oozing out of the holes. Everything was on 'hold' until I found another tank. That took years until I found the rolling chassis a couple months ago. But I digress...
Your suggestion is spot on given the info in my original posting, and I appreciate the input. Meanwhile I have these oversize CRs and would like to use them. A Canadian friend of mine who is a dedicated builder of Can-Am race bikes told me that many snowmobiles of various displacements use tapered adapters because they all run the same carb. Another friend who is a former #1 plate holder in AHRMA formula 200, and something of a 2-stroke wizard, advises me that I would never get them right. I respect his judgement but disagree.
Best regards, Buzz

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