Greetings to all, Alcohol blend fuels are becoming a fact of life and sooner or later we are going to have to deal with it. Viton is the best elastomer choice for ethanol blend fuels. If you want to know more about Viton(FKM) then read this excellent document produced by Oak Ridge National Laboratory http://info.ornl.gov/sites/publications ... b27766.pdf The conclusion of that document is that Ethanol blend fuels are worse than pure Ethanol and that NBR, what your carb seals and o-rings are made from. is the worst material to use. Now the richness problem with Mikuni BDST carbs, which I am sure many of you are aware of. Most carb seals are there to stop the fuel leaking out. However, the BDST carbs have seals that stop fuel leaking into the throat. They have to be in top condition or your bike will run rich and no amount of fiddling with float heights, mixture screws, main jets or needle clips is going to solve your problem. Please read this assembly guide Guide to Assembling Mikuni BDST Jet Housing Also check the condition of the needles and emulsion tubes. There are several good guides on the internet that discuss wear of those two parts and Factory Pro needle jet, emulsion tube, mikuni, keihin, carburetor, troubleshoot is one of them. Now where is all this leading? Well I have been developing carb kits in Viton for various models including the Ducati Monster and SuperSport are coming on stream now. I am aware that there is a no advertising policy on this forum, as there are in most, and I apologise if my post is seen that way but I prefer to see this as an infomercial. A member could stumble across my website and post a link to it here, but I would prefer to introduce myself and let members know that I control the production of these parts so if you have a problem or a special request then it can be dealt with promptly. Here is a direct link to the Ducati page Ducati Carburetor Kit Monster & SuperSport cheers Blair McIntosh
Interesting thread - thanks for that. I'm rebuilding a 900ss currently and have no idea how it will run.........
A timely post. Just started putting the carbs back together on the weekend but had to stop as I missed an o ring. I was quite happy with what I was doing but the web site was useful as a confirmation so thank for that. Sorry I bought the part a while back. I was trying to look for the closest readily available size either metric or imperial but gave up and bought the proper ones. This looks like it might have been a wise move especially with the one under the slide housing so glad I went for the correct size. Another thing I found for putting carbs back was not to grease the choke slide as this attracts dirt. Thinking about it I would agree with this - maybe someone else could confirm. While I am on has anyone go a supplier for the overflow lines, these seem to be quite a hard tube 6mm.
A bit of overkill perhaps but I used Bing 1/4" ID hose. You can see it in the pic here Guide to Placement of Mikuni BDST Float Bowl Vent O-Ring It is available in the UK from Rans Fuel System Parts, Primers, Clamps, Pipe, Fittings, Tanks etc All at Skycraft You did the right thing with both the slide housing o-ring and not putting grease on the choke slide. The slide housing o-ring is not in the Ducati parts book that I have, weird.
