Hi all,

I'm going to use a set of MC18 carbs on my MC16, so I don't have any air solenoids!

I have been searching though the forum and understand that I need to "block" the air pipes with something like #170 main jets.

I understand that Matt from Tyga have been running a somewhat equal setup on a MC21?

I will of course need to jet the carbs to suit my setup but that's not a concern at present.

Each MC18 carb have two air tube connectors. And as seen in the technical section I have an X-connector and a T-connector (http://tech.nsr-world.com/nsr/mc18/mc18-power-jets/).

If someone could explain where I should add restrictors (main jets) I would appreciate it very much...

Please don't double post. The reason no-one answers a particular question is usually either because it's something no-one else has experienced yet, or is something someone doesn't feel comfortable answering.

The vast majority of questions are answered within a few hours, and I don't think you'll find anywhere with more support, but sometimes there are things you just have to experiment with yourself!

The only person I personally know of so far to have a go at this sold his NSR years ago, and is no longer active on the forum. I'm afraid, just like the rest of us, sometimes you have to just get in there with the available data and get your hands mucky!

Starting with MC18 jetting may be a good way to go, but it's really down to you at the moment. Please don't try and open a jetting discussion outside the Members area, and please don't double post.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Hi Andy,

I'm sorry to have upset you.
Didn't see this as a double post, as the question raised here is rather specific and not related to jetting from my point of view.

I was looking for some knowledge regarding the air solenoid setup, but as I can tell I'm probably on my own here... I don't mind getting my hands mucky at all, only affraid to end up running lean with engine damage as the result.

I won't bother you anymore, but I might post the experience I gain later...

I'm not upset, but it does frustrate me when posters seem to think they are being ignored. I've seen it many times where someone is convinced they are not receiving the support they require because of ulterior motives, and this simply isn't the case.

This is purely a classic example of an extremely uncommon issue that very few that I am aware of have any experience with, and people are therefore unqualified to comment on. Also, as you say, for fear of running dangerously lean, I expect it's another reason why people don't even want to speculate where to start.

The only setup that doesn't use the solenoids is the HRC F-III, but that barely resembles any standard NSR setup, the parts are difficult to obtain, and not very suitable for the street either.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Waldo, don't mind Granty......he's missing the Happy times

However, as he so rightly says, you'll have to suck it and see, as it's a little outside the norm.

What I've done before on an MC18 is not use the solenoids and fit main jets to the hoses. I'm not gonna get specific for fear of getting it mighty wrong as I haven't done the 16, and the 18 I did wasn't stock.

The MC21 I did was to replicate the F3 carbs. It seemed to work pretty well.

Steve and Andy (and others probably) will want to shoot me, but what I did was take a saw to a set of F3 carbs so that I could see and measure what was inside (orifices etc). From what I found it was quite simple to replicate.

Anyway, if you go this route, remember that the MC16 exhaust port is tiny, so bigger carbs without other mods may not be the way to go. But if you do, start by plugging the hoses with small jets, which will keep it rich (safe) and then adjust accordingly.

As a tip (not real numbers). Say you start with a #100 main jet plugging the hoses, this will give you a bench mark fuel flow. If you then increase to a #110 main jet then you will lean off the bottom end a little, but lean off the top end a lot.

If the engine feels good at the bottom but lean at the top, reduce the plugging jet size.

Good at bottom, rich at top, increase plugging jet size.

Lean at bottom, good at top, increase main jet, increase plugging jet.

Rich at bottom, good at top, reduce main jet, reduce plugging jet.

You're looking to get the fuel flow curve right with the plugging jets.

Feel free to post your finding and I'm sure there will be help and ideas offered.

The MC16 F-III uses 28mm carbs, and in "standard" HRC form (i.e. all the HRC bits bolted together but unmodified) is rated at 68hp!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Andy wrote:The MC16 F-III uses 28mm carbs, and in "standard" HRC form (i.e. all the HRC bits bolted together but unmodified) is rated at 68hp!

As you say Andy, the MC16 F3 uses 28mm carbs...........

I don't believe this is an F3.

If anyone's fitted bigger carbs to the stock 16 it would be a good time to let us know how it went.

Hi Matt,

Thank you very much for the information...

That's very helpfull and also along the lines I was thinking.

About my bike, it will be a MC21 engine but running MC16 electrics and MC18 carbs!

Not a great setup I know, but that's the parts I could source
And not much left of the orig. MC16 anyway...

I'm a bit puzzled by that fact that the MC18 carbs I got have 2 pipes connected for what I expect to be air correction?
Unlike the MC21 where I believe there's only air correction pipe/tube for each carb?
I'll start plugging each pipe (4 in total) with rather small jets and see where that brings me... See Andy no jet sizes mentioned

I'll get my hands dirty as soon as the parts I ordered arrives from Tyga