Red Top Carbs (seeking info)

David M

David M

X
Today I stumbled across a set of 46's from a friend of mine at a killer deal which sparked some interest to obtain more information about these carbs. I was wondering when and by whom these carbs were made. Also what is particularly good or bad about them and how do they work compared to other aftermarket carbs like blackjacks, novi's, ect. Been hunting for some novi's for a not so mild limited sxr but for the price I am considering these for the time being........
Anybody got any good or bad things to say about them???...or just some general info would be nice! Thanks in advance! David
 
crammit442

crammit442

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Big Kahuna said:
Hey David, Red Top carbs are similar to the Blackjacks. For a race application they are good carbs.
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They are similar to Blackjacks in that they're annular discharge carbs. They're actually good for any application and are very friendly for tuning. They work especially well in freestyle applications since they run high popoff pressures and hit very hard. Carbs that run low pop tend to be tough to get right on superjets because the yamaha motor tend to be a bit of a shaker. Talk to RMBCfreeride(Neil) about jetting specs for them. He was running a set on one of his boats and said he liked them a lot.
 
RMBC Freeride

RMBC Freeride

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crammit442 said:
.....Talk to RMBCfreeride(Neil) about jetting specs for them. He was running a set on one of his boats and said he liked them a lot.
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Wow, how did you remember that Charles? Yes I was running them on my Team Scream 8mm Lamey p/v when I got it. They were Red Top 46's jetted by Team Scream - I did not change the jetting at all & I have it written down if it helps.

I have since switched to a set of Full Spectrum 46's that I think are even better. Definitely cleaner at lower RPM's thatn the redtops were. However, I think the pop-off in the Red Tops was set pretty low FWIW.
 
crammit442

crammit442

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RMBC Freeride said:
Wow, how did you remember that Charles? Yes I was running them on my Team Scream 8mm Lamey p/v when I got it. They were Red Top 46's jetted by Team Scream - I did not change the jetting at all & I have it written down if it helps.

I have since switched to a set of Full Spectrum 46's that I think are even better. Definitely cleaner at lower RPM's thatn the redtops were. However, I think the pop-off in the Red Tops was set pretty low FWIW.
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I just remembered us talking about them on the beach at Lanier a couple of years ago.:biggrin:
 
RMBC Freeride

RMBC Freeride

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Here are the jetting specs I had:

Dual 46mm Red Tops on 783cc Lamey P/V stroker...

Main - 117.5
Pilot - 127.5
N/S - 2.5
Spring - 95g
return line restrictor: #70 Main Jet
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
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Clearwater Fl.
I had to set the pop-off lower for a Blaster engine setup for Closed Course Racing!
I'm sure you would need a little bit higher popoff and rejet for freestyle.
 
David M

David M

X
so you guys think these these would work well for a limited class sxr(closed course)??? I'm considering both a used set of red top 46's and used novi 46's but the price difference is the cost of an advent!!! :grumble:
 
crammit442

crammit442

makin' legs
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David M said:
so you guys think these these would work well for a limited class sxr(closed course)??? I'm considering both a used set of red top 46's and used novi 46's but the price difference is the cost of an advent!!! :grumble:
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If they work similar to Blackjacks(which they should) they should do very well. Very easy to tune and even if you don't race they'll work well for rec/freestyle also.:smile: Art at Jetworks should be able to get you in the ballpark for use w/an SX-R.
 
sjetrider

sjetrider

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David M said:
so you guys think these these would work well for a limited class sxr(closed course)??? I'm considering both a used set of red top 46's and used novi 46's but the price difference is the cost of an advent!!! :grumble:
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I would go Red Tops over Novis all day for freestyle. But dunno nothing bout no racing. Just know I cant tune a novi for bottom end to save my life.
 
David M

David M

X
I got bills number, he did some work for me before naty's, i just might have to give him a call; had no idea he ran blackjacks! thanks bro!
 
SUPERTUNE

SUPERTUNE

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Clearwater Fl.
Lifted from greenhulk...
---------------------------------------------------------------------------
Comparing Signal Statistics - Having made all these different statements about the importance of signal, the next logical thing to do is post the actual signal data (as measured on a flow bench). Nearly each of the aftermarket carb makers produces (and strongly promotes) the 44/46mm butterfly versions of their line. Given this, we considered it most relevant to list the data for these diameters. The only exceptions were the Buckshot BRM (they promote the 47mm instead of a 46mm), and the Keihin 42mm (the 42 is the largest race carb that Keihin makes).
The following data was gathered on a Super Flow 600 flow-bench set at 20 inches of water for all tests.
Along with this data, we have also denoted the full throttle CFM numbers, as measured at 20 inches of water. They are listed in alphabetical order by carburetor brand name.
Carburetor (signal@100%open) Main Circuit Pilot Circuit CFM @ 20" (100%open)
Buckshot Magnum 44 31.0 23.3 268
Keihin CDK II 42*** 28.8 22.5 195
Mikuni Super BN 44*** 49.0 30.0 230
Mikuni "I" Body 44*** 32.2 22.5 239
Novi Max Flow 44 66.0 25.7 269
Red Top 44 37.9 20.3 269
AMC 46 31.7 21.5 293
BMR Full Spectrum 46 58.0 23.0 299
Buckshot BRM 47 41 - 47.5** 20.5 293
Buckshot Magnum 46 37.2 26.0 286
Mikuni Super BN 46*** 46.0 34.8 253
Mikuni "I" Body 46*** 33.0 23.2 246
Novi Max Flow 46 65.0 28.0 304
Red Top 46 34.8 21.0 296
** The signal reading randomly fluctuated on a 2-4 second cycle within this range, with no stabilized 20" reading lasting over 5 seconds. Signal reading would not stabilize until pressure was reduced to 8".
*** Tests were run with bolt-on arrestor adapter.
-----------------------------------------------------------------------------
So here's my take,
If you look at the Aftermarket SBN 44's and 46's they produce the best low speed signal out of the box than any race carbs in this guys testing posted on the greenhulk forum.
I'm not saying stock super BN are the best...just they will work very well on all kinds of modified engine setups, big cc or little cc. I have found that the CFM flow of the carbs IS NOT the primary concern for me but rather how clean and crisp the engine response is after lots of throttle stabbing that freestyle/freeride riders do for pulling off tricks.
One of the reasons I say to use the dual 46's even on stock modified 701cc engines, compare the low speed carb signal on the 46 to the 44...46's had more signal!
From this guys chart HE tested the novi maxflow as the best CFM flowing carb with Ed's Full Spectrums in second, Now keep in mind the specs are probably outdated to the current modified carbs today. But overall a decent test with a flowbench.
The best setup I use for Pro freestyle engines (Race fuel/MSD-TL/all the goodies) has been the new Novi Freestyle 48's. (just don't use their spec's/develop your own)
Chuck
 
Last edited:
SuperJETT

SuperJETT

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This is actually GroupK's info, not greenhulk's.

SUPERTUNE said:
Lifted from greenhulk...
---------------------------------------------------------------------------
Comparing Signal Statistics - Having made all these different statements about the importance of signal, the next logical thing to do is post the actual signal data (as measured on a flow bench). Nearly each of the aftermarket carb makers produces (and strongly promotes) the 44/46mm butterfly versions of their line. Given this, we considered it most relevant to list the data for these diameters. The only exceptions were the Buckshot BRM (they promote the 47mm instead of a 46mm), and the Keihin 42mm (the 42 is the largest race carb that Keihin makes).
The following data was gathered on a Super Flow 600 flow-bench set at 20 inches of water for all tests.
Along with this data, we have also denoted the full throttle CFM numbers, as measured at 20 inches of water. They are listed in alphabetical order by carburetor brand name.
Carburetor (signal@100%open) Main Circuit Pilot Circuit CFM @ 20" (100%open)
Buckshot Magnum 44 31.0 23.3 268
Keihin CDK II 42*** 28.8 22.5 195
Mikuni Super BN 44*** 49.0 30.0 230
Mikuni "I" Body 44*** 32.2 22.5 239
Novi Max Flow 44 66.0 25.7 269
Red Top 44 37.9 20.3 269
AMC 46 31.7 21.5 293
BMR Full Spectrum 46 58.0 23.0 299
Buckshot BRM 47 41 - 47.5** 20.5 293
Buckshot Magnum 46 37.2 26.0 286
Mikuni Super BN 46*** 46.0 34.8 253
Mikuni "I" Body 46*** 33.0 23.2 246
Novi Max Flow 46 65.0 28.0 304
Red Top 46 34.8 21.0 296
** The signal reading randomly fluctuated on a 2-4 second cycle within this range, with no stabilized 20" reading lasting over 5 seconds. Signal reading would not stabilize until pressure was reduced to 8".
*** Tests were run with bolt-on arrestor adapter.
-----------------------------------------------------------------------------
So here's my take,
If you look at the Aftermarket SBN 44's and 46's they produce the best low speed signal out of the box than any race carbs in this guys testing posted on the greenhulk forum.
I'm not saying stock super BN are the best...just they will work very well on all kinds of modified engine setups, big cc or little cc. I have found that the CFM flow of the carbs IS NOT the primary concern for me but rather how clean and crisp the engine response is after lots of throttle stabbing that freestyle/freeride riders do for pulling off tricks.
One of the reasons I say to use the dual 46's even on stock modified 701cc engines, compare the low speed carb signal on the 46 to the 44...46's had more signal!
From this guys chart HE tested the novi maxflow as the best CFM flowing carb with Ed's Full Spectrums in second, Now keep in mind the specs are probably outdated to the current modified carbs today. But overall a decent test with a flowbench.
The best setup I use for Pro freestyle engines (Race fuel/MSD-TL/all the goodies) has been the new Novi Freestyle 48's. (just don't use their spec's/develop your own)
Chuck
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