Expert: Arcticatman - 12/14/2004

Question
Hi, I recently bought a 1974 Arctic cat Panther 440 Single Carb. It ran when I bought it but the stock Walbro carburetor that is on it is in ruff shape, gas leaks and squirts out everywhere. Personally I hate the walbro carb itself and would like to swich over to a Mikuni. I have the Mikuni to put on but was wondering if you knew if this would work?. also the walbro main jet size is .076. Is there a conversion chart from Walbro to Mikuni so I know what the proper main jet size would be?. And if you would know the proper size the Mikuni pilot jet should be that would be great to. But any help you can provide is greatly appreciated. Thanks Kyle.

Answer
Hello Kyle,

  The old WF floaters like to do that when they get old. That's a good idea, but you may run into some trouble doing it. It has been done before, but with varying results. To start, the WF-1A Walbro carburetor that you have now, has it's own built in fuel pump, where as the Mikuni ( I believe you have a Mikuni VM round slide type carb?), has to have a separate fuel pump. Unless you have a diaphragm type Mikuni. In this case, you would need to install a fuel pump, and run a line off of the engine, to the fuel pump, ( there should be a fitting, where the Walbro's impulse hose hooked up to the crankcase). Also, I'm not sure if you have a flange mount or spigot. If the two carbs are different in the way they mount, you will need to buy a rubber flange, for the Mikuni to mount it to the intake manifold. Another part you will need is a new throttle cable for the Mikuni Now, as far as the jets, there is no standardized charts. So, here is what I would use for a Panther: MAIN JET  for Mikuni: 330. PILOT JET for Mikuni: 35. That is based on using a Mikuni VM 34 carburetor, which is best with that sled. If you decide to go ahead with the conversion, but are using a different size carb, let me know and I will recalculate the jet sizes. My recommendation is to rebuild the carb. I don't mean a cheap kit that just holds it over. Dennis Kirk has a very good kit that should really fix it. Here is a link if you want to check it out:  http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=1739&store=Main&...   .  I really hope this helps you out, in deciding what to do. If you need any help at all, let me know! Good luck with the Cat! --Arcticatman