mikunis t140

Stahlgewittern

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As anyone fired Mikunis to t140 Bonnie .my Amal 2s are a bit worn and thought these would be a better option.
 
I have, last year. But…

I'd rebuilt the whole motor, with different cams, compression, pipes and so-on meaning that 'standard' jetting on both 32mm Mikunis and the old MK2 Amals has been out.

Having some spare Amal needles and jets I've refitted the MK2s and been able to ride it, but it bogs on fast throttle opening with either carb on.

It'll be fully run in soon, so I'll get the mikunis back on and get it to a Dyno.

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I have had a Mikuni on a Commando. More expensive than Mk 2 Amal but better quality IMO. I believe that Amal Mk2 jets etc. fit though which could be useful. Allens Nottingham are the guys to go to for Mikunis. Good for advice as well as sales.
 
I have had a Mikuni on a Commando. More expensive than Mk 2 Amal but better quality IMO. I believe that Amal Mk2 jets etc. fit though which could be useful. Allens Nottingham are the guys to go to for Mikunis. Good for advice as well as sales.

I've finally got around to sorting my jetting in time for some winter green lanes , thanks to a kit from Allens. Steve there asked me questions about how it felt and engine spec, then prescribed a set of new jets & needles.

It is now perfect! Tickover is smooth even set low, pickup is great and a constant throttle faultless. Allens and Mikuni are now Highly recommended.

15707510656_18312b5fbd.jpg
 
I've finally got around to sorting my jetting in time for some winter green lanes , thanks to a kit from Allens. Steve there asked me questions about how it felt and engine spec, then prescribed a set of new jets & needles.

It is now perfect! Tickover is smooth even set low, pickup is great and a constant throttle faultless. Allens and Mikuni are now Highly recommended.

15707510656_18312b5fbd.jpg

I like that Sir!:clap
 
I've finally got around to sorting my jetting in time for some winter green lanes , thanks to a kit from Allens. Steve there asked me questions about how it felt and engine spec, then prescribed a set of new jets & needles.

It is now perfect! Tickover is smooth even set low, pickup is great and a constant throttle faultless. Allens and Mikuni are now Highly recommended.

15707510656_18312b5fbd.jpg

Mark,
I also have a modded T140 with twin 32mm Miks, what did you end up with jetting/needle wise? Mine runs well (or will do when I sort the headgasket!) but is overly sensitive to too much choke (had to go to a bar mounted choke to deal with this)and not convinced it is right around smaller throttle openings (needle, cutaway)

Engine mods on mine are Megacycle 1030 cams (now discontinued, but basically a slightly hotter 1060) dialled in.
Gilardoni barrels wil low comp pistons (as only low comp available with the compatible Asso pistons)
P&M lightly gasflowed head
Belt drive
One way breather from front engine mount
Pazon smartfire ignition and iridium plugs
dynamic balanced crank and billet lightning rods:blagblah
Dunstall copy silencers (was on peashooters)

What spec do you run??

I see you seem to have gone to slightly wider clips on the Mikuni rubber inlet stubs, did yours (as mine did) regularly blow off with any small backfire (or even ometimes without?) otherwise? :blast

Did you ever dyno yours - looks like it's used as they should be!

Cheers

Dave
 
Hi Dave,

I've only just seen your post. My spec is modest in terms of top-end, but nice and punchy and it has silly-low gearing too (18:48 I think, so revs out far too easily):

650 cams (3134?) with 750cc, using higher comp pistons than standard (can't remember what ratio now, but feels like a good 650 to kick, so probably 9:1 ish).
Belt drive primary and a micro digital boyer (I do like the pazon tho, having put one on my father-in-law's bonnie recently).
Billet rods on balanced crank and a selection of headers and silencers to suit the silence required by the occasion (MoT/Scrutineers/trailriding/ respecting neighbours/ rural fun).

My jetting went loads leaner than I started, but I didn't have to change the slide/cutaway:

175 mains replaced my 230s
a longer, leaner, more parallel 6DL2 IIRC needle in middle clip replaced the original 5L1? on the leanest clip
The needle jet was a totally different design with a shield sticking into the air around the needle and no holes in the side.
I have the ref number for it in the garage, but it's too cold to venture out there tonight!:D

Now it carburates so nicely, I've forgotten plans for a dyno day, unless there is a '£10 a run' open day or similar, when I can take a random variety down there for fun.

I'll check the numbers when I get into the garage. It's cold Oop North:D

16374424942_ab186b1306.jpg
 
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