Anyone using a Mikuni VM16 ?

[Ratchetbirds]

Hello and asking if anyone has experimented installing the Mikuni VM16 on a chinese 66cc bike? I've been searching here all day off and on and haven't found too much posted. Hoping to not re-invent the wheel so to speak, but can do it myself if needed. Any info would be appreciated.

 

[rustycase]

RB, I have not tried one on my ht, but have always had good results with mikuni carbs... they are a REAL carb and parts are available for them at local mc shops. A quality product, as opposed to, well...
Good luck!
rc

 

[Ratchetbirds]

Thanks Rusty, that is why I am buying one. Totally tunable no matter what you do to your engine and set-up. It's almost better than sex.

 

[Ratchetbirds]

In case anyone else is considering the Mikuni VM16 here is a tuning PDF from Mikuni. 20 pages explaining how their carbs work and how to adjust it throughout the entire throttle opening range.


www.mikuni.com/pdf/vmmanual.pdf

 

[DaveC]

I have a tiny 12/14 Dellorto on my Morini and a Mukuni is what I've been looking at to replace it. Where did you get yours? I'm thinking a 15-16mm carb and not a 19mm Dellorto. I had a Mukuni Flatslide on my SuperKart and learned just how good they are then.

A decent carb and decent expansion pipe should get the most power from my S5 E Morini

 

[Ratchetbirds]

Heya Dave,
Haven't bought it yet just trying to get all my ducks lined up. Most common price for the VM16 is around $90. It's a clamp on with a spacer on the inlet, and has a 28mm intake side for the filter. Everything on it reminds me of my Weber DCOE 45 on my MG midget...see photo. One of my other babies. Except I can change the venturi size even on my Weber, too cool. I am also looking at a K&N 62-1370 Crankcase vent filter as my intake filter for this carb. There is another VM16 for the XR50 that has a flange mount and sells for under $60 but I don't wanna make a custom intake just yet.

 

[Ratchetbirds]

Okay,
Just bit the bullet and ordered it from Treatland. $93 with shipping by priority mail. Very excited. I will try to do all my work and log it with pics here if anyone is interested.

 

[bairdco]

i'm using one on this bike:

or at least i was, until the motor finally grenaded.

i never re-jetted the carb at all. i bought it from a swap meet, new in the box for 5 bucks. it didn't have an air filter.

after making a custom intake, it idled fine, but would die out with any more than half-throttle. i figured i'd have to re-jet it, and went to some local places looking for some.

i found an air filter and after putting it on, it worked awesome.

mine's the flange mount, and the intake was made out of scrap aluminum and alumiweld soldering rods. took a few tries to get the angle right, but it worked great, no leaks...

more info on that bike is here: http://motorbicycling.com/f38/one-more-40s-colson-add-fleet-21037.html

 

[Ratchetbirds]

Bairdco,
Very nice work you do there. I take it you have access to machine tools and a TIG welder. I see lotsa custom sweetness there.

 

[bairdco]

nothing but hand tools. no welders, drill presses, lathes or nothing. the only power tools i own are a dewalt cordless drill, a port-o-band bandsaw, and a harbor frieght bench grinder.

it's all done by will, skill, and hammers.

 

[Ratchetbirds]

Nice, at least I don't see any duct tape. The use of the tools that you have still qualifies you as a craftsman for the quality of work you produce. I am very lucky in that I do have access to many machine tools as well as a TIG, but most of the work I am doing on my bike I am trying to do in a more simple way. So far it is working out ok, just takes lotsa paitence. You seem to be gifted in that way. Keep it up.

 

[Ratchetbirds]

I think we should all just ignore that newbies post.

Here we are boys and girls. Got the carb yesterday and got to photo it just a few minutes ago. As you know, I am going to share said photos. These first 4 are of the exterior, obviously. This is the Mikuni VM16.

 

[Ratchetbirds]

Now for some interior shots. First up are the slide parts. 5 positions for the clip on the needle, folks. Five...hehehe. Next up, real brass floats. A metal float bowl with a superb sealing surface that the paper gasket can seal onto. Took alot of work to seperate the bowl off for the first time. Won't be any leaks coming from this bowl. Lastly, lookie all the jets. This carb screams to be dialed in completely. Gonna be a bit of a road to haul, but it will be worth it. I promised myself I wasn't going to go crazy on my bike, but I broke that promise, shucks. Ordered my expansion chamber and a gen II manic mechanic head. Thinking on a custom stainless intake, not sure yet, the stock one will work fine. Oh and also ordered an adjustable magnet to dial my timing as will be needed. Building Rohmell's simple CDI right now as well. More updates on this carb as they come.

 

[Ratchetbirds]

Well, had a brain moment tonight about my intake. The manifold side of the Mikuni is actually 21mm, and my grubee intake manifold is 19mm OD. I took the plastic spacer out of my Dax RT carb with it's o-ring and it is actually 21mm OD....soooo, I slid it all together and tightened it up. Holds very well and I think there will be no mounting space issues. We shall see.

 

[bairdco]

Ha! couldn't of been running too great if the engine grenaded!

it ran great for 8 months. wide open throttle everyday at speeds over 50mph.

it finally blew up after i did some more experimental mods to it. basically, i was doing whatever i could for that last tiny bit of horsepower, so i could build up a race bike with what i learned.

150 buck kit + 8 months of abuse + a learning experience to make the next one better (and stronger) = money well spent.

a lot of people don't even get 8 months out of their stock kit sputtering around at 25mph.

(edit) just noticed you're in california. if you're near costa mesa and you wanna see what a real bike can do, look me up..

 

[IreBo]

Well, had a brain moment tonight about my intake. The manifold side of the Mikuni is actually 21mm, and my grubee intake manifold is 19mm OD. I took the plastic spacer out of my Dax RT carb with it's o-ring and it is actually 21mm OD....soooo, I slid it all together and tightened it up. Holds very well and I think there will be no mounting space issues. We shall see.

So whats the verdict?? im curious to see if the mik 16 is a good carb for these, it seems perfect! how she run?

 

[Ratchetbirds]

Just got my motor back together this weekend and got it running but ran out of time. It runs well but I need to get a few more hours into it before I can make a full report. Changed my bearings, seals, resealed the crankcase, added an adjustable magnet, new CDI, and a Manic Mechanic gen II head, as well as adding the Mikuni. As you can see I have done alot of work in the last few weeks. I am working overtime all this week at work as well, so I may not be able to get back into it until this coming holiday weekend.

 

[rustycase]

Gosh, RB, will look forward to seeing the full report when you get more time!
rc

did u have an X pipe already???

 

[Ratchetbirds]

Morning RC, I have an SBP x-chamber that is still in the box. Not going to install it until I am ready to install the SBP shift kit. Since the motor mounting changes with the shifter I will wait till then to put it on. That Manic gen II head is WELL worth the cost, though. I have to pedal a tad harder now to get her started. Even not dialed in I can tell there is a big power increase from that alone.

 

[Ratchetbirds]

Small update. Turns out I have alot of work to do at home this weekend but I am getting some time on my bike. From my first run I felt it was a tad rich, so I adjusted the E-ring on the needle up one notch. It helped quite a bit but I got about 5 miles on her and the botton end of the carb needs adjusting a bit. I feel it is a tad lean but not totally sure just yet. I don't go any faster yet, but I get there faster. Meaning this baby gets up to top end about 40% faster that it did as stock. I will work my air needle screw a bit tomorrow. Once carb feels better it will be time to tinker with the timing. I am extremely pleased with the change in performance I am already feeling.