Thom Green & Mikuni size?

[Mick Milakovic]

Hi Thom and all,
What size Mikuni did you put on you MC5?  How have things worked out for you?  I might need to go another direction than a bing with my 250 project.  Gatorback is approaching quickly and I still don't have my 250 running!

[Big Mac]

Mick - I heard from Thom earlier this week, but I think his internet connection is on the fritz, thus no word from him on this... I'm 99% sure he got a 34MM Mikuni ordered from Pro-flo that they set up special by boring to 35MM. This is because the 34MM is shorter than the 36MM to fit in the tight space afforded the shorter Bing, and the 35MM supposedly performs best. Thom said all his starting problems went away and it performed much cleaner down low. Cost him about $110 from what I recall, and they sent a bunch of jets with it too.

The connection to the airbox can be a hassle, since the Mikuni is much smaller at the rear than the Bing. Other than your own custom hardware/autoparts store setup, you may want to check //www.ozktm.com since they're making a lot of varying rubber connectors for different size carbs and swaps for old KTMs. Takes a few weeks to get something in from Aussie land, but I got one that worked great for around $18 including shipping. Great deal.

Good luck with it.  Mac

[tomale]

Mic and Mac
Mac is right that is just what I did. It took a few times out to get it to run the way that I thought it should but it works great.  I had to modify the intake manifold a bit. It was too long and I cut off about 1/2 an inch. I then ground down the ridges on top and bottom and cleaned it up so that a the rubber between the carb and the intake manifold fit better. I found a intake on evilbay so that I would not have to destroy the stock one. Just covering my bases... IF you need me to give you the jets that I ended up with I would be more than will to do so. I think that the Main is 280 and the Pilot is 45 but I am not sure about that so start with really big and work you way down. I use to know a guy we called Tinker. He said that when he was jetting a new carb he would leave the Main out and get everything else right, then start with a really big main and work your way down. Most people do not really use the main jet all that much any way and it is really easy to miss the right size Pilot. If it is right it should have really good trottle response and is clean and crisp with no flat spots. Based on what I hear at the starting line I think most guys never mess with the carb, regardless of the conditions they are riding in. A bad Idea and you could very easily lose alot of potential power and torque.
As for the puter it is getting better but It still seems to be having trouble. This is one of many things I know little about.
Good luck on the carb

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
78' 400 MC5