Forum

[Jassie]

Hello to all. On my 1960 Fury I wish to use a mikuni carb. I don't want to use the GP carb as orignal. I wanted to find out if a flat slide carb will be better or a round slide. What size of carb will work better as orignal was 1.5 inch. Also what kind of jetting will be ideal.
Thanks in advanced for any input.
Jessie.

[Bullet Whisperer]

Hi Jassie, I made one work very well on a 38mm MK II Amal, if that's of any interest. Here is a link to a very short video featuring this machine. Regards, Paul. ... https://www.youtube.com/watch?v=yiYNNJ8soAE

[Tim NZ]

For street use, and not-in-anger track use 36 - 38mm will be fine.
Jet size will depend on if you are using Mikuni 'amal' (4/042) jets; start with a 320 style or Reverse (N100/604)drilled jets : #160


Needle 6DH4 - 6DH8?


Exhaust system used, air filter, head flow capabilities will all mean for variations, so you are for the most part on your own...

[Bullet Whisperer]

The Fury featured in my video runs perfectly with the 38mm Amal and I can give the settings for the carb on this machine, as I set it up and have the settings written down if needed. Incidentally, the machine appears to idle a little quickly and erratically, but that was on full [manual] advance - it idles slow and steady when retarded. Funnily enough this machine came back to my workshop yesterday, under new ownership, to have a full engine strip to replace the original alloy conrod with a forged steel one, for peace of mind.

[Bullet Whisperer]

Just looked through my notes and with the standard exhaust system and no air filter, this machine runs the following ... slide - No3, needle - bottom groove [richest], needle jet - 107, main jet - 380, pilot jet - 45, starting jet [choke] - 60, air screw - 1.5 turns out. Ignition timing - 33 - 35 deg, or 11mm btdc @ full advance.

[Jassie]

Thanks for the info. Paul and Tim. What do you guys think about flat slide vs round slide carbs. Does one style have advantage over the other.
Jessie.

[Bullet Whisperer]

I reckon as long as you have big enough openings to let the engine have adequate fuel and air, that's all you need. Cossack Urals have flat slide carbs, as a matter of interest. I have always used round slide types, apart from trying a Gardner carb in place of the MK II Amal on our 500 racer - the power went down by 2 bhp, so the amal went back on!

[Adrian]

B.W.is known for getting Mk2 Amals well sorted, though other options are available to you. The original 1.5" equates to 38mm which gives you the choice of Amal Mk2, Mikuni, Dell'Orto or even Keihin, though some suggest that dropping down to a 36mm carb is better for the street.



Allen's Mikuni in the UK, and I'm guessing Sudco in the USA sell round slide VM38 and V36 Mikuni kits for the BSA Gold Star which might be a good starting point, depending on whether or not you can get a good deal on an Amal where you are. I have had excellent results with a Mikuni TM36-31 flat slide carb with accelerator pump on a tuned Electra-X, you can buy these ready jetted for XT/SR500 Yamahas, not too far off for experimenting. Then of course there are the PHF36 and PHM38 Dell'Orto pumpers which just look the business, especially with an alloy bellmouth fitted. My current 500 AVL hybrid loves its 36mm Dell'Orto, and I have this beastie for my current project:



A.

[Wayne]

Hi,

I recently fitted a 36mm Mikuni to my Fury - as fitted to the BSA Goldies off Allens, they were very helpful and the carb was virtually smack on - it ticks over and starts beautifully and I have only dropped the main jet by one size and the mixture is fine.

[Tim NZ]

"Cossack Urals have flat slide carbs"

BW; you call those rectangular pressing things inside Cossack/Urinal carbs Slides?