[goodatbeingyoung]

All,

I'm working on a 2005 with an ACE air canister and a Goldie silencer. It's been giving me carb troubles for a while now so it's time to replace. I'd absolutely love to put an AMAL on the bull, but with how often I ride it, I'd like some reliability.

Looks like Mikuni is the way to go. But, I don't understand the difference between the performance of the flat slide and round slide models. Can someone explain. The other issue I'm having is the lack of space between the Mikarb I've got now and the bottom of the gas tank. There's not much clearance and it seems to be stressing the throttle cable where it enters the carb. Any fixes for that? Or is that out of the ordinary?

Thanks for all the help so far.

[Ice]

 Flat slide can be a misnomer.  A true flat slide has a slide that is just that, flat.

 D slide carbs are quite often ( incorrectly ) called flat slide despite the slide being neither flat nor round but D shaped. The situation is what it is.

 The shape of the slide has an effect on the behavior air as it flows through the carby and gets fuel mixed int to that mass.

In general:
 Round slide carbs tend to be easiest to tune and the round shape of the slide helps them transition smoothly from idle to mid range to WOT.

 Flat Slides can offer incredible throttle response and are hard to beat in the mid and upper revs. In the lower revs it can be a challenge to get and maintain a good fuel air flow and mix. They can test your patience with tuning.

 Between the two is the other "flat slide" the D slide. It has the lovely low end smoothness of the round slide combined with most of the characteristics of the  Flat Slide at higher revs. IIRC most of them have an oval shaped throat with the upper half being wider than the lower half. This offers good vacuum and a strong airflow at lower revs for good fuel air mixing and better cylinder fill while the upper half offers a large volume of flow in the huger revs which allows for better breathing more revs and more power.

  A perennial favorite of the forum for less than all out modded Bullets in the heyday or the Iron Barrel was the 30mm "flat slide".

[ace.cafe]

Cable clearance can be tight under the tank on all the Mikarb and Mikuni carbs. Careful routing helps.
 
I almost always recommend the Mikuni TM32, but on a stock Bullet a VM32 is probably as good for a bit lower cost if a few dollars is a factor. The TM32 is the Fireball carb because the modified engine likes the performance carb. They both need new jets right off the bat, and jetting combinations and settings has a thread in the Tech section they need a matching manifold from Sudco or Ebay.


I haven't used the D slide JRC that was sold here, but some have reported that they liked it.

[tooseevee]

All,

I'm working on a 2005 with an ACE air canister and a Goldie silencer. It's been giving me carb troubles for a while now so it's time to replace. I'd absolutely love to put an AMAL on the bull, but with how often I ride it, I'd like some reliability.

Looks like Mikuni is the way to go. But, I don't understand the difference between the performance of the flat slide and round slide models. Can someone explain. The other issue I'm having is the lack of space between the Mikarb I've got now and the bottom of the gas tank. There's not much clearance and it seems to be stressing the throttle cable where it enters the carb. Any fixes for that? Or is that out of the ordinary?

Thanks for all the help so far.

            I'm very happy with the TM32 I installed on my '08 AVL after the ACE headwork in 2014. It was a season long learning experience, but I soon understood the little bastard in detail and can remove and reinstall it in my sleep now. Much tweaking can be done without removing it, but not everything. I can't give you tuning advice for your particular engine because my engine is far from stock (totally reshaped comb chamber, better flow, huge valves, 9.8:1 comp) and I had to learn what my engine wanted from the carb by lots of experimentation. My only "big" problem is with the spring and top cover when removing and replacing it is necessary as in playing with needle types and height  adjustments, but that's to do more with my hands and wrists (they don't do what I need them to do any more) than the actual difficulty level. No problem for people with no pain issues.

         You can get any shape throttle cable entry tube you might need (straight, 90 or 45 degree) from SUDCO. I've got perfect, smooth action with the straight one by meticulous tweaking, cable routing, etc.. (I'm a meticulous tweaker by nature  ).

          Remove the hot tube (if you have one) from the muffler end of your header pipe if you haven't already; it's very restrictive. You don't want to go through dialing in a TM32 (or any other) with it in there and then do it all over again when you realize you need to remove it to get the most out of what you've already done (carb, exhaust, air intake). 

        Radiator hose is good for your transition tubes from head to carb and from carb to canister.

[Adrian II]

You can get any shape throttle cable entry tube you might need (straight, 90 or 45 degree) from SUDCO. I've got perfect, smooth action with the straight one by meticulous tweaking, cable routing, etc..

tooseevee is on the money here, part of the problem is that the factory changed the carb mounting over the years, later ones have an alloy stub bolted to the inlet flange on the cylinder head, with the carb fitted via a piece of rubber hose. Compared with the one-piece mounting rubber used on the earlier 500 Indian Bullets, this moves the carburettor backwards, which means that the throttle cable run now risks fouling the underside of the gas tank, which never used to be a problem.

Let's say you're going to use a Mikuni VM30 roundslide carb (I think Niche Cycle on are still selling them as part of the complete Sudco kit for the 500 Bullet cheap on ebay), the Sudco kit has a spacer and one-piece rubber mounting that will keep the carb closer to the engine. Anything mounting the carb further back will probably benefit from the angled throttle cable ferrule. This also needs a shorter outer cable to compensate, if you're careful and don't damage the inner, you can trim back the outer of an existing cable.

A.

[goodatbeingyoung]

In general:
Round slide carbs tend to be easiest to tune and the round shape of the slide helps them transition smoothly from idle to mid range to WOT.

Flat Slides can offer incredible throttle response and are hard to beat in the mid and upper revs. In the lower revs it can be a challenge to get and maintain a good fuel air flow and mix. They can test your patience with tuning.

Between the two is the other "flat slide" the D slide. ...

Most of my riding is done in the city and I'm lucky to be in 4th or 5th gear for more than half a mile or so. Sounds like the round slide will better meet my needs for now. Otherwise, do recommend a particular D slide carb to check out?

[goodatbeingyoung]

Cable clearance can be tight under the tank on all the Mikarb and Mikuni carbs. Careful routing helps.

I almost always recommend the Mikuni TM32, but on a stock Bullet a VM32 is probably as good for a bit lower cost if a few dollars is a factor. The TM32 is the Fireball carb because the modified engine likes the performance carb. They both need new jets right off the bat, and jetting combinations and settings has a thread in the Tech section they need a matching manifold from Sudco or Ebay.

Cable clearance is indeed tight. I'll have to look into the angled cables that TooSeeVee mentioned. I'll definitely check out that tech thread too. Do I have to change the intake manifold? Seems like what I've already got might be just fine (which is a radiator hose cut to size) as shown.

If I do need to change it, I'd love to replace it with a metal part instead of rubber, but I can't seem to find one. This is about the best I could find: https://www.ebay.com/sch/m.html?_odkw=&_ssn=niche-cycle&_armrs=1&_osacat=0&_from=R40&_trksid=p2046732.m570.l1313.TR12.TRC2.A0.H0.Xmanifold.TRS0&_nkw=manifold&_sacat=0

I like this setup but don't need the air filter or throttle cable (the bike came with a replacement):
http://www.ebay.com/itm/Royal-Enfield-500-30mm-VM30-Complete-Mikuni-Carburetor-Kit-2000-Later-/171814323098

[goodatbeingyoung]

tooseevee is on the money here, part of the problem is that the factory changed the carb mounting over the years, later ones have an alloy stub bolted to the inlet flange on the cylinder head, with the carb fitted via a piece of rubber hose. Compared with the one-piece mounting rubber used on the earlier 500 Indian Bullets, this moves the carburettor backwards, which means that the throttle cable run now risks fouling the underside of the gas tank, which never used to be a problem.

Let's say you're going to use a Mikuni VM30 roundslide carb (I think Niche Cycle on are still selling them as part of the complete Sudco kit for the 500 Bullet cheap on ebay), the Sudco kit has a spacer and one-piece rubber mounting that will keep the carb closer to the engine. Anything mounting the carb further back will probably benefit from the angled throttle cable ferrule. This also needs a shorter outer cable to compensate, if you're careful and don't damage the inner, you can trim back the outer of an existing cable...

This is definitely spot on as it's not a problem on most of the bikes I've seen online. The added distance in my setup (I attached a picture above) moves the carb a little too far from the intake and causes exactly this problem. I'm having a hard time finding only the intake parts included in this ad (as shown below): http://www.ebay.com/itm/Royal-Enfield-500-30mm-VM30-Complete-Mikuni-Carburetor-Kit-2000-Later-/171814323098

I've got a fresh new throttle cable that I'm sure I could trim down if needed.

[Adrian II]

That is the same kit I was referring to. Your picture clearly shows how the carb is pushed too far back with the later manifold.

If you want the individual parts try contacting Sudco, I think they have a fairly large on-line catalogue.

A.

[strat71]

for illustration..
i put a TM32 Mikuni on 2003 bullet.. with Ace manifold and air box... here's the layout...
not sure a VM32 would fit with this manifold.. the flat side has a lower profile than the VM32.
Ben

[Ice]

Here's a pic of the D Slide "flat slide" carb on Bill Harris's AVL powered Harris Scrambler.

[finbullet]

Most of my riding is done in the city and I'm lucky to be in 4th or 5th gear for more than half a mile or so. Sounds like the round slide will better meet my needs for now. Otherwise, do recommend a particular D slide carb to check out?

This is a really good D slide carb. I have one installed to my iron barrel. And not even expensive. I used a mikuni rubber manifold for older snowmobiles ( more info about the setup, if you type "cheap performance" on the search)which brings the carb near the head, so there is plenty of room for the cable.
http://m.ebay.com/itm/32mm-High-Performance-Carburetor-GY6-Baster-Banshee-Scooter-Like-PWK-Black-Serie-/161810498601

[Adrian II]

I have wondered about these bargain basement carbs, what if any re-jetting did you have to do to get your C.I. Bullet running sweetly with this one?

A.

[Bill Harris]

For the Harris Scrambler, I got the Taiwan PWK 32mm carb from JRC Engineering.  They manufactured and mounted the flange on the carburetor for me, all I need to do was to rejet: 42 pilot, 142 main and moved the needle one notch richer.

jrcengineering.com

Royal Enfield people are good people

Cheers,
Bill

[finbullet]

I have wondered about these bargain basement carbs, what if any re-jetting did you have to do to get your C.I. Bullet running sweetly with this one?

A.

I got it jetted with those jets, which came with the carb (usually 3 main jets and 2 pilot jets and 2 needles).  The carb uses the same jets (those hexagonal jets) as a genuine keihin does.
But if you order one of these carbs, make sure the picture shows those hexagonal jets and not the small round ones.

[goodatbeingyoung]

This is a really good D slide carb. ... ( more info about the setup, if you type "cheap performance" on the search) ...
http://m.ebay.com/itm/32mm-High-Performance-Carburetor-GY6-Baster-Banshee-Scooter-Like-PWK-Black-Serie-/161810498601

Is this the thread you're referring to?:

https://forum.classicmotorworks.com/index.php/topic,22936.msg260738.html#msg260738

If so, I was hoping I might find a little more info there. But, it sounds like you were able to find some carb jets you liked. Any more specs on your setup? I'd love to see a picture of the manifold too.

[goodatbeingyoung]

As the hunt continues, this is happening:

https://youtu.be/gc8Bgvv5mF4

Is this a carburetor issue? It seems to have appeared out of nowhere as I rode it quite a bit the day before. There's quite a bit of gas leaking from the carb at this point while the bike is still (in case that evidence helps a diagnosis). I'm going to be purchasing a new carb this week! Help me decide!

[ace.cafe]

Could be carb issue.  Leaking carb is never good.

[Chuck D]

As the hunt continues, this is happening:

https://youtu.be/gc8Bgvv5mF4

Is this a carburetor issue? It seems to have appeared out of nowhere as I rode it quite a bit the day before. There's quite a bit of gas leaking from the carb at this point while the bike is still (in case that evidence helps a diagnosis). I'm going to be purchasing a new carb this week! Help me decide!

Fuel tap left on while bike is off? Bad practice. Float valve stuck open maybe? Things to check anyway.

[goodatbeingyoung]

Fuel tap left on while bike is off? Bad practice. Float valve stuck open maybe? Things to check anyway.

I was thinking it might the float valve so I pulled it apart and tightened things up. Didn't seem to help much.

[Chuck D]

Hmmm... When you say "tightened things up" what'd you do in there? The carb works just like a toilet. If the floats are too high they'll prevent the valve from opening up and admitting more gas. Conversely, too low and the valve will never shut off. Sometimes while monkeying around in there you can inadvertently bend the delicate little metal tang that  seesaws between the floats and the valve itself. Done it myself. Or there might be a speck of dirt doing the same thing. Or maybe the floats are not sliding up and down freely due to some dirt or corrosion. Or, the floats could be saturated, say because of a pinhole, affecting their buoyancy.
You get the idea.
Having fun yet?

[goodatbeingyoung]

Hmmm... When you say "tightened things up" what'd you do in there?

I brought the tang up a bit as it seemed like the float was letting in way too much gas (it was leaking from the carb if I left the gas on after about 5 minutes). Didn't seem to make a difference. Everything else seemed clean in there and I could see the float and needle working as well as I'd expect them to. Did you take a look at the video I linked above? Might help a diagnosis.

[Yamahawk]

Check the float needle and seat. If the needle has a neoprene tip, check it for a groove or debris embedded into the neoprene. If it is metal tip, then check for a groove in the tip itself. If either of these is present, then you need a new needle and seat. In a Mikuni, these are available for replacement. Check the seat for dirt or debris also, and if necessary, clean it. Re-check your float height using the specifications from Mikuni for your particular carb also. If this doesn't stop your leak, then you have a crack somewhere lol...
Hope you find the problem!
Charlie

[blasphemous]

Use this to diagnose your Carb, the Micarb is a very simple carburetor to work with:
http://www.hitchcocksmotorcycles.com/pictures/content2/micarb_notes_-_a4.pdf

[tooseevee]

This is definitely spot on as it's not a problem on most of the bikes I've seen online. The added distance in my setup (I attached a picture above) moves the carb a little too far from the intake and causes exactly this problem. I'm having a hard time finding only the intake parts included in this ad (as shown below): http://www.ebay.com/itm/Royal-Enfield-500-30mm-VM30-Complete-Mikuni-Carburetor-Kit-2000-Later-/171814323098

I've got a fresh new throttle cable that I'm sure I could trim down if needed.

            When I set up my TM 32 after I got my head back from Ace, I made sure that my piece of radiator hose that mates the carb to the manifold Ace provided was short enough to allow the mouth of the carb to touch the mouth of the manifold. Sometimes an 1/8" or a 1/4" matters when you want a clean entry for your cable.

            When I have my float bowl off for some reason, I check my needle valve by very gently holding the valve shut with one finger and opening the petcock. If I can listen to one medium Dylan track (maybe Tangled UIB) without my hand getting soaked I'm pretty sure it's sealing OK. If it leaks out the overflow later with the bowl back on and the petcock on it probably means the floats aren't pushing up hard enough to make a good seal. That tells you your height while the valve is relaxed might need tweaking.

[finbullet]

Is this the thread you're referring to?:

https://forum.classicmotorworks.com/index.php/topic,22936.msg260738.html#msg260738

If so, I was hoping I might find a little more info there. But, it sounds like you were able to find some carb jets you liked. Any more specs on your setup? I'd love to see a picture of the manifold too.

Yes, that is the thread I was referring to. About the setup, I have a free flow exhaust and a boyer ignition with a pertronix flamethrower coil. Otherwise all original. I will try to take a picture of the manifold,on the bike tomorrow. You can look it up on the internet with the key word 07-100-08, the manifold is a bit tight with the carb and you have to file those bolt holes and the upper part of the manifold flange a bit, but with this manifold you don't get any steps in the intake path, because the manifold ID is 32mm. The rubber of the the manifold seems to be good quality, two years running and still no leaks and the carb isn't even supported anyway.

[Yamahawk]

            When I set up my TM 32 after I got my head back from Ace, I made sure that my piece of radiator hose that mates the carb to the manifold Ace provided was short enough to allow the mouth of the carb to touch the mouth of the manifold. Sometimes an 1/8" or a 1/4" matters when you want a clean entry for your cable.

            When I have my float bowl off for some reason, I check my needle valve by very gently holding the valve shut with one finger and opening the petcock. If I can listen to one medium Dylan track (maybe Tangled UIB) without my hand getting soaked I'm pretty sure it's sealing OK. If it leaks out the overflow later with the bowl back on and the petcock on it probably means the floats aren't pushing up hard enough to make a good seal. That tells you your height while the valve is relaxed might need tweaking.

Or the classic Dylan track, "You Gotta Serve Somebody"... back in his gospel days... "well, it might be the devil, or it might be the Lord, but ya gotta serve somebody" 

[Arizoni]

Just a few things to look at when the bowl is off of the carb :

Remove the float valve seat from the carb.  Most have a gasket under them and sometimes this gasket will crack.
If it does, it will let fuel into the bowl even if the float and valve are working.

Also, if the float is a metal one, they can develop small pinhole leaks that let fuel get inside.
If this happens, the float won't close even when there is too much fuel in the bowl.
The way to check it is to shake remove it from the carb and shake it.  If you hear/feel anything sloshing around in there, you've found your problem.

[goodatbeingyoung]

...

            When I have my float bowl off for some reason, I check my needle valve by very gently holding the valve shut with one finger and opening the petcock. If I can listen to one medium Dylan track (maybe Tangled UIB) without my hand getting soaked I'm pretty sure it's sealing OK. If it leaks out the overflow later with the bowl back on and the petcock on it probably means the floats aren't pushing up hard enough to make a good seal. That tells you your height while the valve is relaxed might need tweaking.

That's a great tip! I'll give it a go tomorrow. Simple, effective & entertaining. I'll definitely report back tomorrow.

[goodatbeingyoung]

Just a few things to look at when the bowl is off of the carb :
Remove the float valve seat from the carb.  Most have a gasket under them and sometimes this gasket will crack.

I went ahead and opened the carb to see that a small part of the gasket was worn away on the bowl itself. Is that what you're referring to? I've attached a picture.

Also, if the float is a metal one, they can develop small pinhole leaks that let fuel get inside.
...

Gave the float a good shaking and everything's in good order! Thanks for the tip! It does however seem that the float is a little low according to the link that someone recently provided. I'll have to make some adjustments there as well.

[goodatbeingyoung]

      When I have my float bowl off for some reason, I check my needle valve by very gently holding the valve shut with one finger and opening the petcock. If I can listen to one medium Dylan track (maybe Tangled UIB) without my hand getting soaked I'm pretty sure it's sealing OK. ... That tells you your height while the valve is relaxed might need tweaking.

I chose the times they are a changin and had zero leakage. So, I'll have to get that float adjusted. I've attached a picture of its height. I'm pretty new to carb adjustment, but it seems to me that wouldn't cause the trouble that I'm having. Here's the link (again) to the video showing what's going on in case you missed it.

https://www.youtube.com/watch?v=gc8Bgvv5mF4

Thanks again for the help!

[finbullet]

Here's a pic of my carb setup with the rubber manifold.

[goodatbeingyoung]

Thanks. Looks like a pretty decent fit.

[longstrokeclassic]

As some of us have discovered, without some additional support on the inlet side of the carb, those rubber manifolds don't last too long!  My choice of filter had a metal back plate so an 'L' bracket was the easiest option

[ace.cafe]

Yes, the far end of the inlet tract must be supported.
The OEM filter airbox and the Ace Air Canister both incorporate it into the designs.
The bracket Ric showed also performs the function.

[Arizoni]

goodatbeingyoung
No.  The torn gasket area you show in the picture is not the float chamber valve seat.

The carb in the picture in this link may not be the same as yours but item # 33 is the gasket I was referring to.

https://www.google.com/imgres?imgurl=https%3A%2F%2Fwww.xbhp.com%2Ftalkies%2Fattachments%2Fthumpers-2-stroke-exotics%2F172102d1424017520-yamaha-rx-100-mikuni-carburetor-theft-replacement-carb.jpg&imgrefurl=https%3A%2F%2Fwww.xbhp.com%2Ftalkies%2Fthumpers-2-stroke-exotics%2F31212-yamaha-rx-100-mikuni-carburetor-theft-replacement.html&docid=VVOEEphgUf4Z3M&tbnid=sIWnclTiEMxS2M%3A&vet=10ahUKEwjGnPG7ndrVAhWExFQKHdkBD_sQMwg2KBEwEQ..i&w=853&h=621&bih=937&biw=1680&q=micarb%20carburetor&ved=0ahUKEwjGnPG7ndrVAhWExFQKHdkBD_sQMwg2KBEwEQ&iact=mrc&uact=8#h=621&imgdii=As6WH8UnUxgD7M:&vet=10ahUKEwjGnPG7ndrVAhWExFQKHdkBD_sQMwg2KBEwEQ..i&w=853

[finbullet]

Yes, the far end of the inlet tract must be supported.
The OEM filter airbox and the Ace Air Canister both incorporate it into the designs.
The bracket Ric showed also performs the function.

I know the carb inlet should be supported, haven't figured out yet how to do it. I tried to hang it with a steel wire, but the wire always snapped so have to figure out something else. Maybe a different kind of filter.

[goodatbeingyoung]

goodatbeingyoung
No.  The torn gasket area you show in the picture is not the float chamber valve seat.
...

After checking the float needle, I didn't have any problems with leakage. It seems that it was realted to the float height. I've got that sorted out now, but I'm still experiencing the same problem. I also cut a new gasket for the bowl itself, but nothing's changed. I'm planning on ordering a new carb today. I like the Mikuni, but haven't found anyone who might be able to to do anything other than send the product my way (no support after purchase). The guys at jrcengineering.com have been super helpful so far. I'll likely purchase from them when the time comes.

I'll go through the steps here: http://www.hitchcocksmotorcycles.com/pictures/content2/micarb_notes_-_a4.pdf

And if that doesn't work out, it's new carb time!

[goodatbeingyoung]

Pulled the spark plug out tonight and it was as black as could be. I'll swap it out and see if that cures my ailment, but it's only been in the bike for a month or two. I don't want it to happen again anytime soon. What are the causes?

[Hoosier Bullet]

Pulled the spark plug out tonight and it was as black as could be. I'll swap it out and see if that cures my ailment, but it's only been in the bike for a month or two. I don't want it to happen again anytime soon. What are the causes?

I am pretty sure I am familiar with your carb, and your bike, based on knowing the previous owner.

The float height on the mikcarb carburetor you have was altered in a failed attempt to get more gas into a hot rodded engine.  It didn't run rich on that engine (mine), but rather too lean.  Now on your engine it runs rich (yours doesn't have the compression, cams, et cetera), thus fouling your plugs in short time.

In addition to being junk, mikcarb is too small for a hot rodded engine.  In middle tennessee elevation a mikuni TM32-1 with 27.5 pilot, 389 series P6 needle jet/stock TM32-1 needle (5FP17?) and 180 main jet is the solution to your troubles, and also a pathway to higher performance, which I have a feeling you are going to be looking for in the near future.

ATV unlimited on eBay used to have the cheapest carbs.  Niche cycle on eBay has the needle jets and main jets.  The pilot jets for the Mikcarb work in the TM32-1.  Sudco has the nice motion pro throttle cable.  They also have a rubber intake manifold to make the carb mount on the engine.  But it is better to get a metal intake manifold from Ace Cafe and connect the carb to manifold with a cut down piece of radiator hose.

The TM32-1 has a narrower cross section than the mikcarb or the mikuni roundslide, so it will fit easier than either of those and also not foul the throttle cable.  Can't say if that is the case with the JRC carb.  The JRC carb is probably not enough for a worked engine with pistons cams bigger valves et al.

Just sayin'.

[Adrian II]

Th UK supplier of the JRC carbs has them in sizes up to 34mm, presumably they are available in the USA as well.

A.

[Ice]

The JRC 32mm carb on the Harris scrambler quite nicely supports the free flow intake and exhaust, Reddich S grind cams and performance TCI.. I believe the JRC 32 and 34 mm carbs would do what a person would need a carb of those sizes to do.

[goodatbeingyoung]

I am pretty sure I am familiar with your carb, and your bike, based on knowing the previous owner.

The float height on the mikcarb carburetor you have was altered in a failed attempt to get more gas into a hot rodded engine.  It didn't run rich on that engine (mine), but rather too lean.  Now on your engine it runs rich (yours doesn't have the compression, cams, et cetera), thus fouling your plugs in short time.

Awesome info! This is some info that I dug up about what I think is my bike. Are you familiar with any of it?

* Mikuni TM32 flat side carb (removed before sale)
* Alloy barrel
* Stage 1 cylinder head
* Sam Rat rocker rollers
* Hi-comp piston w/rings (coated)
* new Goldie style exhaust pipe

In addition to being junk, mikcarb is too small for a hot rodded engine.  In middle tennessee elevation a mikuni TM32-1 with 27.5 pilot, 389 series P6 needle jet/stock TM32-1 needle (5FP17?) and 180 main jet is the solution ...

ATV unlimited ... cheapest carbs.  Niche cycle ... needle jets and main jets. Sudco ... throttle cable. 

I'll have a look at those

The pilot jets for the Mikcarb work in the TM32-1. 

Would those be the jets that I've got in the 28mm carb I have now?

... it is better to get a metal intake manifold from Ace Cafe and connect the carb to manifold with a cut down piece of radiator hose.

That's exactly what I've got now, so I'll stick to it!

[goodatbeingyoung]

When I spoke with Nick at JRC (who has been incredibly helpful) he mentioned that a larger carb outlet into a smaller manifold and intake on the engine side would be bad for performance. If my current manifold is 30mm and my inlet port is 33mm, what's my best bet?

[ace.cafe]

Your best bet is to use a 32mm Mikuni carb and matching manifold for your 33mm port.
This has been proven beyond any shadow of doubt for many years.

Smaller carbs lose top speed performance,  and larger carbs sacrifice low rpm torque. A close match to the port is desirable. 32mm gives a half -mm transition of the right type into that very slightly larger port, which doesn't impede the flow. It's as close as you are going to get. Why fight it?

Does anyone really think that I would spec that package for the Fireball for ten years if I knew of something better at an affordable price?

[goodatbeingyoung]

Your best bet is to use a 32mm Mikuni carb and matching manifold for your 33mm port.
...

Does anyone really think that I would spec that package for the Fireball for ten years if I knew of something better at an affordable price?

Absolutely not! You're the expert! I'm going to be buying a Mikuni today. Thanks so much for everyone's help!