Update on single Mikuni carb

[harold]

Although as I have said in previous posts, this is way more trouble on a Baghira then most would want, bit I finally have it dialed in. I learned a lot about telling rich from lean, and went through the same jets more than once. My setup now is:
42 Mikuni HSR
147.5 Main jet
25 pilot with screw at 1-1/2 turns
97 needle with clip at one down from the top

One of the problems with jetting is that the bike will run different after just getting warmed up, then it will when run until it is hot enough to turn on the fans. I don't ride it that much, and so it has taken longer than I anticipated.

Disadvantages:
On a Baghira at least, it is a bitch since there is a frame member in the way that has to be removed.
The carb has to be mounted around 6" from the head, leaving little room for an air cleaner, but enough at least if you are street riding.
You have to make a bottom cover plate since the air box is gone, to keep dirt from the wheel coming up.
You have to fab a mount for the carb, since it is so far back that the rubber manifolds can't hold the weight.
You have to modify the throttle cable inlet on the carb a little, and get a longer cable made.
AND, you have to make a manifold. None are sold anymore, and the one that they used to sell, wouldn't fit a Baghira anyway.

Advantages:
You can change the needle or its clip position in around 2 minutes.
You can change the main jet in around 2 minutes.
Changing the pilot jet requires carb removal, and that takes around 10 minutes for the whole process, with no cussing.

On the stock Baghira, any of these would take me several times longer, since there isn't enough room to get the carbs off easily as the frame is in the way of moving the carb back. It took me 2 tries to get my stock carbs off, and 1/2 hour to get the rubber manifolds back on with the first failed attempt. It was probably longer than that, not even counting the time it took to calm down on the first failed attempt on just getting them back on. If you can remove your Baghira's carbs easily, then you are a better and probably younger man than me.

Biggest advantages:
Jets, needles, e-clips, or anything else on the carb is readily obtainable. You can't say that about the stock carbs.
If you don't already have one, like I did, you are buying only one carb that is everywhere on EBay, instead of two.
IT RIPS.
Acceleration and the snap of it is improved to where I finally got a 2nd gear power wheelie. Flipping it in 1st is only prevented by good judgment. Stock, on this bike at least, the front wheel never left the ground in any gear.

Top end power:
I sold my previous Honda XR650L to my friend, and the day I did we went riding. While I had jetted the Honda to where it would power wheelie 2nd, and the MZ wasn't even doing 1st, we were dead even on a drag race up to 60, or roll on at 60mph. After that the MZ would slowly pull away. We did another test yesterday, and I walked away from him everywhere. A roll on at 60 for around 10 seconds, and I was at 90 and he said he hit 80 before we had to slow down for traffic. When he rode it, he said it was noticeably more powerful than before, or his Honda now.
I did add 2 teeth to the rear sprocket, but as mentioned in the post about that, I couldn't tell a difference. That's not even a 5% change.
The carb made a change even before I had it dialed in and changed the rear sprocket.

The bike is a blast now, but of course in the ever ceasing need for more power, I guess I will go to a higher CR piston and stage 1 cam. I installed Bill J's ignition module today, and the rev limit is higher, which helps when you are trying to really get on the gas. My next simple mod will be to make a sideways turn for the muffler, so that I can get next to someone peddling a bike, and let them feel the pulses that are coming out. You can blow the hat off of someone standing behind the open glass pac muffler, by blipping the throttle. As you get older, you have to take your pleasures where ever you can find them.

[basser23]

good write up,I'll save those jetting recommendation..plan on a single HSR for the Skorp using your method