'74 450wr Best Carb Choice?

All the parts for the Bing 54 arrived. They all look nice in the packges. As much as I would love to try them out right away, I am not sure when I will be able to put this bike together. Sunday the 5th I was out riding with a few friends up near Manchester, VT. They were planning out a dual-sport ride for the local bike club. Everything was going well. I was riding my 07 Husaberg FE550e which I just had the suspension revalved, put a steering damper and rejetteted the carb. The bike was running great and handling great. The next thing I knew, it was sometime on Tuesday and I am waking up in the hospital in a lot of pain. I had a fractured skull, broken skapula(?---part of shoulder blade), couple fractured ribs, head trauma, had to have surgery on my knee and other various pains. It all kinda sucked. I got out of the hospital on Thursday and have been laying around the house. I feel a little better each day. Not sure how soon I can ride again, but, I am looking forward to it.
Today, was the NETRA enduro put on by Berkshire Trail Riders called "Hell in the Hills". I really wanted to participate in this enduro, been planning on it for a couple months. Oh well, hopefully there will be next year.
All in all, I am thankful to be alive as a couple mph could have made a difference.

Mark

You havent ridden a 125 Husky obviously.

I have several Maicos, ('73 450 and '79 440, trying to buy a '76 400GS) and the first thing I did was take off the Bing and Motoplat and put on a Mikuni and PVL. I've ridden the '81 490 and its mostly hype, Barry Higgins told me a few years ago he prefers the '79 Magnum to the '81 Mega 2. I agree.

The only bikes I have not removed the Bing and replaced it with a Mikuni are my Pentons because its so hard to get it to fit in the tight area between the engine and airbox. This is not a problem on Husky's or Maicos.

Does the PVL make a big difference?

Depending on the bike it can be a huge performance increase, some not so much performance but a reliability issue. The PVL is an internal rotor ignition, and IMO 175cc and smaller bikes work best with as light a flywheel mass as possible. Take Husky 125s for example, they came with the standard Mini 6 Motoplat, not a huge flywheel, but they respond much quicker, rev quicker and are easier to keep "on the pipe" with a smaller flywheel like the internal rotor PVL. Some open class bikes like Maicos have huge crankshafts so they can also use an internal rotor, but others like the '74-'79 Penton/KTM 400s, which come with exactly the same size flywheel as a Husky 125, are nearly unrideable because they have such violent power delivery even with the stock flywheel and need a bigger one, which on some GS models they added. The main reason I put either a PVL or MZ-B on all my Vintage bikes is, again IMO, Motoplats were of marginal reliability brand new, and 30-35 years of aging has not improved it any. Opinions differ though, so take mine with a grain of salt. Likely the same people who swear by a Bing will probably also swear by their Motoplats.

Well, I have the parts for the Bing. So I am going to try it out. However, I won't waste my time with the Motoplat. Any recommendations on where to purchase an MZB?

You can buy through any established motorcycle dealer. Penton Racing only sells through dealers

or you can buy the directly from the source in Germany...Believe it or not it's cheaper than any other place or seller that I've seen in the states...

http://www.powerdynamo.biz/eng/sitemap.htm

Hi Folks - nice information on this thread thanks for sharing. I am trying to track down some information in relation to carbs, does anyone has baseline settings for the Mikuni on the 1974 450? A friend of mine has one and is not having much success... his latest attempt was
40 pilot
390 main
Q8 Needle jet
2.0 slide
He said it was was still bogging down once he got it started...
Any help would be much appreciated :-)

I ran a Mikuni VM38 on my 73 450 40 +plus years ago but I don't remember the jetting. I don't have the memory I used to but it wasn't much to begin with anyways.

John LeFevre at VintageHusky.com would be happy to provide you with a jetting starting point. You'll need to know if the carb is a 36 or 38mm. Keep in mind there are many factors that affect carb function and jetting. On these old bikes I think the number one culprit of tuning problems are air leaks at the many gasket surfaces and the two crankshaft seals. Other factors that can cause hiccups include ignition, worn carb parts, carb adjustments, dirty carb circuits. Sorry I can't offer more specific help.