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#599048 - 05/11/15 10:05 pm 36 MM Mikuni  
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I have a 36 MM Mikuni on my 1955 CB. I also have jetting specs from GS Ron and Stan Millard of B50 fame. I would like to gather jetting from other people for comparison. So...can anyone give me specs for a 36 and or 38 Mikuni round slide?

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#599149 - 05/12/15 4:15 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Kerry W has posted on this subject I'm pretty sure. Maybe reach out to him in a PM. He's good people and forthright with information. (Most of which I do not understand.)

My $.02

Last edited by stubbicatt; 05/12/15 4:15 pm.

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#599202 - 05/13/15 2:04 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Middle East,
Ok, after typing lost of stuff and making a careless click, I lost the lot. Here goes again.

Compared to all versions of the Amals, I'm a big fan of the Mikuni VM 'roundslide'. Other carbs will be better again, but look even less appropriate (e.g. various flat slide carbs). The Mikuni is cheap, Mikuni-original spares are reasonable consistent, no dearer than AMAL stuff and readily available. The carb material is much better than AMAL (I've never seen a worn one) and the range of adjustment, especially on the needle/needle jet (where we all usually ride on the street) is MUCH finer than AMAL provide. After fitting a 36 to my DBD is ran as well or better than the 1 1/2" GP and used HALF the fuel. Plus it was a first kick starter and idled like a B33.

Allens Performance in the UK sell 36 and 38mm kits. They only offer the bigger kit because some people have to have the big carb, same size as the GP they're taking off, though they tell me that the 36 makes the same power on the dyno and better mid-range. I had a couple of near-new 36's and they willingly told me what they suggest for a starting point for jetting. I'll add that at the end, and you can compare with what I ended up with.

The Mikuni downsides are that it just doesn't look like an AMAL, even a Concentric or MkII, making the bike seem that bit 'non-standard' and 'foreign' and a bit of work to sort out fuel hoses is required, but it's not rocket science. If you are using a MkII (and perhaps MkI) AMAL the throttle cable will swap straight over, though a new one will be required if you have a GP. I'd strongly recommend an inlet adapter rubber flange thingy from Surrey Cycles in the UK (a Mikuni one doesn't have the right hole spacing), as it pulls the carb neatly in under the tank. They are available (not too badly priced) in 36 and 38mm (and possible smaller).

The choke is different on a Mikuni: it's a proper enrichener, which becomes progressively less effective as the throttle is opened - it's almost ineffective at any more than a small opening. As a result, it cannot be used to assist with main jet testing, like the GP version can. There are three methods of choke operation: a common version is a lever setup, which runs from the choke fitting on the right/front of the carb to a lever accessible on the left of the carb: not that handy, as it's hidden away behind the cylinder. I used the other common option: a 'pull-up' knob, though this is a little hidden by the lower right rear edge of the tank, but not really an issue. Best option is a cable fitting (Mikuni part, readily available), which would allow the use of a standard AMAL-style choke lever on the bars. Cables are readily available.

As for basic settings, I filed away as many versions of what other people were using away for some time before I started the changeover. I did this for AMAL MkII's as well, as I had both. I had more spares for the Mikuni, so persevered with that. What I found was that my bike liked settings that were quite different to what others use and even those that suited my Velo Thruxton (I did the change on both at the same time).

Mikuni adjustable pieces are: air jet (the tiny jet in one of the holes in the bell mouth many people don't know about), needle jet, needle, pilot jet, float height (+ float needle valve, of flow rate into the bowl - a 3.3 will be fine), main jet and slide cutaway.

My BSA was a DBD34, with 2442/2446 cams, good ignition, set at 36* BTDC, standard pipe and silencer, NGK B8ES plug on 95 octane (98 if I could get it) unleaded gas.

Here is what Allens recommend:
38 or 36mm
240 main jet
159 P8 needle jet (the '159' designation is the style of needle jet to suit that carb - there are several versions of carb body, so use a needle jet of the same series - alternatives are possible, but keep it simple - the 'P8' is the size of the hole)
6DH3 needle (dual taper, fairly shallow)
nil slide recommendation
nil air jet recommendation (the tiny jet in one of the holes in the bell mouth many people don't know about)
35 pilot (big gains in low speed running/starting can be had with pilot jet setup - adjust size so that the mixture screw is about 1 1/4 to 1 1/2 turns out when it's nice and stable)

After 9 or 10 gradually improving setups, I ended up with:

1 1/8 mixture screw turns from fully in
30 pilot
18.5 mm float height
2.5 slide cutaway
159 P6 needle jet
6DH3 needle (second clip position from the top)
210 main jet
0.5 air jet

I didn't get it to the dyno to check air/fuel ratio out the exhaust, but it ran pretty well, with a very light plug colour (ignore the standard charts you see in the manuals..). Starting and slow speed running became a party piece..

Notes: I started with a 35 pilot, but the mixture screw needed to be 2 3/4 turns out for best running. Going down to a 30 brought that back to where it should be, though a 32.5 might have been a touch better. The air jet comes in sizes from about 0.1mm, from memory, to 2.0mm. I tried a 0.7 but ended up with a 0.5 after making other changes. The 0.7 was perhaps as good or better. The 2.5 slide was what I had and was certainly not too lean, though could have gone up a little (sizes not comparable to AMAL, plus the steps are smaller): that said, it wasn't too rich either, given performance and fuel consumption. The needle was a dual taper ('D' and 'H'), with a fairly steep overall taper (3). (The '6' denotes the body size of carb the needle is made for - most 36 and 38 VM's are a '6' series body). Mikuni needles are an area where it's easy to get confused: basically, 4 strokes tend to like single taper needles, and fairly steep ones at that (i.e. one letter in the designation). I tried a few different ones, but the 6DH3 was arguable the better one.

In short, have a go: the parts/kits are not terribly expensive and the results can be very pleasing, plus there's a certain satis faction in making it work. Start with a few adjustable items (needle jet, main jets, pilot jets, air jets - all quite cheap) and make careful riding observations and notes and you'll quickly get to a point where it's working well.

Kerry

PS. Now I've written this, I see you have a VM on your CB. What jetting do you have in it? How does it run? Useful thing to try and separate, at the risk of telling you how to suck eggs, is to differentiate between issues at a certain RPM or a certain throttle position. I put tape on the twistgrip fixed portion with some closed/1/4, 1/2, 3/4, full open marks and a white mark (tape or correction fluid) at fully close on the rubber, so I can look down and see what throttle position relates to the observed symptoms..

Last edited by Kerry W; 05/13/15 2:20 am.

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#599216 - 05/13/15 3:48 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Thanks for the long write-up on the ins and outs of Mikunis. I have been fiddling with them for years...i used to buy them for $5-10 in swap meets - a fabulous bargain. I would use them on Nortons and Triumphs, 30-32-34mm. There is no love lost between me and amals.

I am a big fan of the 6f9 needle which works great in twins. So I tried it in the GS and so far (not much testing) it is working well.

2.5 slide
Q6 needle jet
6f9 needle
30 pilot
250 main,,,,I may go lower than this though Stan recommends a 270
2.0 air correction jet.
I have yet to put this thing on the freeway and get the rpm up.

Interesting that you have found the steeper tapers work better. I have found just the opposite, though my style of riding is just cruising.

the 6dh3 needle is very common and I used to use it all the time but the 6f9 is superior. for me. give it a try. for the twins say, Norton single carb, I run:

2.5 slide
P6 needle jet
6f9 needle
210 main
25 pilot
no air correction jet. very good carburetion

#599579 - 05/15/15 9:16 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Interesting that your bike likes the Q-6/6F9 setup. The Q-6 is quite rich, compared to the P-8, so I thought I'd have a look at the effect of the needle on overall needle jet aperture, based on the published diameters (and therefore areas) of the needles at various distances from the top of the needles, versus published diameters (and there fore areas) of the needle jets. Subtracting the differing diameters from the total needle jet area gives available area it various throttle openings.

As expected, the Q-6/6F9 is a touch richer initially, and practically the same with the throttle wide open, but quite a lot richer in the mid-range. In the attached graph, the left (vertical) axis is area i.e. increasing throttle opening and the 'D2', 'D3', etc are the distances from the top of the needle. You can see that the needles are parallel initially, though the 6F9 is more linear and richer in the mid-throttle openings.

I'd expect the 6F9 to be a good option, though my bike ran fine with the 6DH3 - any richer in the mid-range and it didn't want to know. I expected it to want to be richer there and checked everything to see if there was an obvious reason, right down to the cam timing -nothing...it was just like that!


Last edited by Kerry W; 05/16/15 10:18 am. Reason: Revised graph

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#599583 - 05/15/15 9:37 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Here's another version (sorry about the washed-out colour - printer running out of ink, I suspect). I've added-in my Velo's setup (which runs very well) - 36mm Mikuni on a P-8/6DP17 needle setup, 35 pilot, 2.5 slide, needle position 3, 0.5 air jet, 240 main jet, NGK B8ES plug.

The Velo's setup is the same at small throttle openings (on the slide, basically), though is quite a lot leaner in the middle, catching up quickly, so that they all cross (in terms of needle jet area with the needle in it) at about 3/4 throttle, with the Velo needle making less of an obstruction at wide open.



I must get the Velo on the dyno this summer with an exhaust gas probe to see whether I'm barking up the wrong tree!

Last edited by Kerry W; 05/16/15 9:03 am. Reason: Revised chart

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Oliver Wendell Holmes
#599639 - 05/15/15 4:32 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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very interesting charts..can you add another pair? Stan uses the 6F5 and Q6...GS Ron recommends 6DH3 and R-O. I have run it with the R-O combination and it ran well. It seems to start easier with the current combination. I have not put it on the freeway yet.
Chart #1...if I leaned my needle one notch I would be very close to your set up.

I believe I am using a 166 needle jet...how does that effect things?

#599691 - 05/16/15 12:17 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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OK, dealing with the last thing first, the '166' is the series of needle jets for the particular Mikuni body you have - there are subtle differences in overall length, the thickness of the flange at the top, etc. It is possible, with minor adjustments or additional of other (Mikuni) parts to interchange some needle jets e.g. trim the top flange of a 159 from 2 to 1mm and add a 'main jet extender' to the bottom of the needle jet (with a washer instead of a brass cup) and it'll fit where a 247 came out of (which is a Yamaha OEM variation). The size of the holes e.g. Q-6 is the same between needle jets. have a look at these diagrams for comparison (sorry, have to use links - can't seem to save the pics to insert here):

'166' needle jet dimensions: http://www.mikunioz.com/product/mikuni-166-series-needle-jet/

'159' series needle jet dimensions: http://www.mikunioz.com/product/mikuni-159-series-needle-jet/#

The charts are based on the same needle position, so dropping your needle a notch in the first graph would move the red line VERY fractional to the right - i.e. a small change in the top half of the needle's range of influence and increasingly less as the throttle was further opened. Changing the needle jet would have a bigger influence in the shape of the red graph between D2 and D4.

I might have some time later to add the other variations...will have to dig out the dimensions of the parts!

Which makes me think that constructing a set of graphs for a given needle jet and showing the effect of different needles might be useful - if it was felt that the fuelling was rich or lean at a certain throttle opening, a different needle could be selected off the graph to make the change and leave the rest of the variations alone....when I have a few spare hours I could do that! Alternatively, I could do the graph with a constant needle and play the changes with the needle jets, though the visible changes would be much finer..

PS Found the R-0 dimensions...will get a graph up later. I just use Exel to do it, but I think there is a pukka programme to easily calculate the data..

Last edited by Kerry W; 05/16/15 1:21 am.

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#599701 - 05/16/15 2:56 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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I would like a set of needles produced that were all the same but had different degrees of single taper. the main dia. would be the same, the starting point for the taper would be the same, the adjusting grooves would be the same...everything but the degree of taper. It would make tuning a lot easier.

I will keep the njet series the same, I have a supply of 166, and a big supply of 159 but not in the Q range. My dyno is the seat of the pants. I believe the 159 can also be used in the 36 but perhaps the position of the metering orifice is not the same as the 166. Thanks for all the info it is good to find someone who is knowledgeable about Mikunis...most people accept the jetting supplied

#599710 - 05/16/15 4:54 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Middle East,
The needles you wish for would make the Mikuni a well-made AMAL, with finer graduations in the needle jet and slide!


No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#599724 - 05/16/15 8:52 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Middle East,
OK, Chart Version 3, with Q-6/6F5 and R-0/6DH3 combinations added. In making this chart I became suspicious that the Q-6/6F9 D3 position (orange line) was incorrect and checked - the needle data for that position was too small, making it seem richer there than it really is. So, the chart above was corrected too... This made me suspect that the data I have for the Q-6/6F5 D2 position was also wrong, but the charted value fits the data I have - I would expect the D2 position to be the same as the D1 position, as the needles are usually straight at this point, so in reality, the D2 position on the purple line may well be on the same line as the purple D1 spot, i.e. same aperture size.

[

Short version is that the R0 setup (pale blue line) is very close to your existing n/jet & needle combination (orange line).

Last edited by Kerry W; 05/16/15 10:23 am.

No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#599774 - 05/16/15 5:39 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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I have studied the Mikuni needle charts many times but they are very hard to use because they have 50 different needles on one chart and the reproduction is also poor. this makes it much more useful. It looks like all these combinations are fairly similar, though yours really richens after D-4. I will try that combination later this summer. Do you use the #159 series?

Compare the R-0/6DH3 and the P-8/6DH3...even though there is a huge difference in the needle jet there is very little difference in the chart. Must be why I have trouble choosing between a P-6 and a P-8 for single carb Nortons. Short of a dyno and an exhaust gas analyzer there is no way to tell.
*is D-3 approx 1/8 throttle? or more?

* can you run a seperate chart for the 6F9 needle using a P-6 and a Q-0 needle jet? Why does the big single require a huge needle jet where the twins are much smaller?
And finally...For the average riderMikunis have way too many adjustments. And Amals have way too little...and theur cheap construction means they loose their metering ability quickly. Their greatest virtue is that they fit the space and when new, do a pretty good job, though I doubt that they are really spot on if you want to nit-pick carburetion. A wide awake chimpanzee can install an AMAL...just don't tighten the nuts very much. So, if they were made out of good material, had a variety of needle jets and single taper needles, they could perform better and be within the capabilities of most riders. Mikunis can be overwhelming in their combinations

#599788 - 05/16/15 11:35 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Middle East,
I'll organise the 6F9 / P-6, R-0 charts later this morning, though perhaps the scale of the chart is not really an indication of relative richness/leanness..I know that my DBD with a 6DH3 needle ran well with a P-6, but ran quite rich on a P-8 or bigger.

While all bikes will be a touch different, there must be a line, approximately the same shape as in the graphs, above which most bikes will be rich and another line, below which they will be lean...between the lines they will run on all combinations..as you say, the Mikuni can offer too many variations for the average owner, and many of those variations will not be required in our machines. I have spent years running racing two strokes with Mikunis, where the variations in needles can make quite a difference; I know of one bike where a change of needle (from something in the usual range, to something quite radical) dramatically changed the way it went.

As for why your experience says the twins run smaller needle jets, I'd expect that was an airflow through the carb thing: we commonly run a 38mm carb off a mid-80's 250 road-racing Yamaha on a late 70's 350, with the same needle, though the 350 needs a smaller needle jet (and the 350 makes more power) - we think it's down to inertia of the fuel and less flow through the carb on a 250 resulting in less flow due to less 'suck' on the carb. In the Brit twin vs. single case, the inertia of the fuel to flow up the needle jet and only getting a suck from one (slightly bigger) cylinder half as often might mean the fuel level drops between sucks more, needing a bigger hole to get enough through in the same time (plus you might be using a smaller carb on the twin? the answer's somewhere in there, I'd say.

I was surprised when I plotted the Thruxton's green P-8/6DP17 combination - the needle was one suggested in some literature I had, for 500 singles (along with the P-6 or P-8) and it proved to be a good choice. I can't recall why I went with the 6DH3 on the BSA - though it will have stayed in because it was better. The 'quite lean in the mid-range' green P-8/6DP17 setup might be good on an open megaphone though!

'D3' on the needle is 1.181" from the top (30mm, i.e. D3=30mm, D4=40mm, etc).I haven't got a slide handy to see how high the needle sits to get a 'throttle closed' position, but I would expect D3 to be closer to 1/2 throttle (i.e. 'on the needle') than 1/8, where the carb would be influenced greatly by the slide.

One thing many don't appreciate fully is that there is MUCH greater overlap between fuel circuits in the carb and 'all jets flow all the time'.

Last edited by Kerry W; 05/16/15 11:41 pm.

No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#599791 - 05/17/15 12:31 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Middle East,
Here you go.

Same needle for both curves (6F9) and needle jets P-6 and Q-0 (i.e. two sizes between them - quite a bit -gives a better idea of the effect of the scale of the chart). As you can see, the bigger needle jet is richer everywhere, but particularly so up to about 1/2 throttle, which would help matters if the slide had a bit much cutaway....



Last edited by Kerry W; 05/17/15 12:32 am.

No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#600094 - 05/18/15 4:24 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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it is surprising to see how much the needle jet can influence starting and idle.

another question..sometimes while idling the goldstar will make a cough..as though it fails to fire on one revolution out of 5. I am sure it is a carburetion problem but I am unable to completely solve it. More apt to do it when warming up but not always. sometimes it is very steady and I can almost count the firings between coughs.

With this size of carb is there a problem with getting enough suction at idle speed?

#600142 - 05/18/15 11:47 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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The 36 (or 38) Mikuni should produce a reasonable idle, though I'm sure it'd never be as good as if you put a, say, 32mm carb on it. There again, the cylinder head isn't really ported for slow speed running either!

How wide is your plug gap and what ignition are you using?

As for the needle's influence on starting and idle...most don't appreciate that the needles are different diameters at the parallel section, as well as having different tapers..the difference in diameters is very small between similar needles, but so is the required fuel flow at that point..

Last edited by Kerry W; 05/18/15 11:50 pm.

No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#600148 - 05/19/15 12:49 am Re: 36 MM Mikuni [Re: Kerry W]  
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Originally Posted By Kerry W
Allens recommend:
38 or 36mm
240 main jet
159 P8 needle jet
6DH3 needle (dual taper, fairly shallow)
nil slide recommendation
nil air jet recommendation
35 pilot hat the mixture screw is about 1 1/4 to 1 1/2 turns out when it's nice and stable)

I ended up with:

1 1/8 mixture screw turns from fully in
30 pilot
18.5 mm float height
2.5 slide cutaway
159 P6 needle jet
6DH3 needle (second clip position from the top)
210 main jet
0.5 air jet
Kerry, thanks to another BritBike contributor recently I was able to go through many back issues of 'Goldie' (UK club newsletter) and 'Twitter' (US club) and photocopy everything of technical interest. To add to the discussion, one member of the now-defunct US club gave as the 36mm Mikuni VM settings for his Clubman:

(no mention of mixture screw setting)
30 pilot
(no mention of float height)
4 slide cutaway
Q5 needle jet
6F4 needle (3rd groove)
220 main jet
(no mention of air jet)

#600165 - 05/19/15 4:46 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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I am very aware of the needles varying in diameter in the parallel sections...it would have been a lot better if Mikuni had kept the parallel sections all the same. It would have knocked out a lot of variables...hence, my idea mentioned above.
** I believe that I am using the 166 needle jet. I will stick with it just to cut down on the variables but everyone else seems to use the 159 series.

That jetting with the #4 slide is some wild stuff...it is extremely rare to see a #4 slide.

#600416 - 05/20/15 1:00 pm Re: 36 MM Mikuni [Re: Kerry W]  
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Originally Posted By Kerry W
I'd strongly recommend an inlet adapter rubber flange thingy from Surrey Cycles in the UK (a Mikuni one doesn't have the right hole spacing), as it pulls the carb neatly in under the tank. They are available (not too badly priced) in 36 and 38mm (and possible smaller).
All this talk of Mikunis made me think of the 38mm that I got with a bunch of parts last year. So, in the spirit of "Why not?" I checked the Surrey Cycles web page last night, where no such adapter is listed. However, I emailed them and this morning a reply from Michael was waiting to say they do indeed have them even though they aren't listed.

After confirming for him that the OD of the flange on my carburetor is 43mm I ordered one for 39-20%vat=32.50 +10 postage. If anyone else wants to do this they don't take on-line orders so you will have to phone to provide your credit card details. From the U.S. dial 011-44-1342-716120. Be warned, though, that although Michael is very pleasant he speaks 'English'. However, you shouldn't find communication too difficult despite that barrier...

I eagerly await the final word in this thread on the proper settings so I can get the necessary jets, slide, etc. Not that I plan to swap the 36mm Concentric anytime soon, but there's no point in having a spare almost-working carburetor.

#600501 - 05/20/15 11:32 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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dave - NV Online content
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dave - NV  Online Content
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Elko, Nevada USA
Last year I received a nice adaptor from Sudco, the Mikuni distributor here in the US to fit a AMAL 38 mm MKII Smooth Bore to my latest DBD road bike I've built up. This adaptor with the rubber tube molded to the flange fits the carb up close to the head. This is unlike the two adaptors I've received in the past from Surrey in England that use a seperate rubber tube that joins the machined alu flange to the carb.
However I'm not aware of the configuration of adaptor now being sold by Surrey. Make sense?
The downside to the Sudco adaptor was the cost at ~ $100.


dave - NV
#600511 - 05/21/15 1:25 am Re: 36 MM Mikuni [Re: dave - NV]  
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Magnetoman Online content
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Magnetoman  Online Content

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Originally Posted By dave - NV
However I'm not aware of the configuration of adaptor now being sold by Surrey.
I'll post a photo of two of the Surrey adapter when it arrives.

#600671 - 05/22/15 5:38 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Kerry W Offline
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Kerry W  Offline
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Middle East,
Here's the Surry Cycles adapter from their website (it's a bit obscure to find):

http://surreycycles.com/product/mkii-adaptor/

dave-NV - the version you mention, with the separate rubber tube between the alloy (usually) adapter and the carb is common for MkII Amals works for the Mikuni, but pushes the carb a bit far back for a good fit under the tank.

As mentioned in the Surrey Cycles link, their version is shorter by 14mm (at least, I'd say) than the 'separate rubber hose' option.

Dunno if I've posted this pic before, but here's the Surrey Cycles adapter with 36mm Mikuni..you can see how the top of the carb fits just under the tank(the top of the carb is actually just forward of the lower edge of the tank, so there is more space above the carb than the photo shows) - extend the carb position rearward by 14mm with the separate-rubber-tube type adapter, and you'll have to pack the tank up to clear the carb top. I tried it.




Last edited by Kerry W; 05/22/15 9:53 am.

No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#600923 - 05/24/15 3:41 am Re: 36 MM Mikuni [Re: SEATTLE GS]  
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Kerry W Offline
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Kerry W  Offline
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Posts: 1,210
Middle East,
MM,

If I was to install a 36mm Mikuni on DBD, I'd start with:

Slide: 2.5 (common to the 36 - might be better with more, which might change the pilot up a size or two)
Pilot: 30
Needle: 6F9 or 6DH3
Needle jet: P-8 or Q-0
Float height 18-19mm to the end of the tangs, carb inverted, from the float bowl gasket face
Main jet: 240 +/- 20
Air jet: 0.5 or 0.7

As usual, there will be any number of combinations that work well, and the setup you mention above, from a US club member would also seem about right. At the end of the day, it comes down to the rider's personal expectations of what is good and the response they are happy with, plus reliable starting and slow speed running.


No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
#600969 - 05/24/15 12:57 pm Re: 36 MM Mikuni [Re: Kerry W]  
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Magnetoman Online content
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Magnetoman  Online Content

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U.S.
Originally Posted By Kerry W
If I was to install a 36mm Mikuni on DBD, I'd start with:...
Thanks very much. As I said in a previous post, it's not like swapping carburetors on my DBD is even on the bottom of my to-do list, but I'll get the parts together in case it ever does make it to the list.

#601019 - 05/24/15 6:09 pm Re: 36 MM Mikuni [Re: SEATTLE GS]  
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SEATTLE GS Online content
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SEATTLE GS  Online Content
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Posts: 614
SEATTLE WA
I will give an update on how my CB runs with the 6F9 and a P-8,.......I had to lean the needle one notch...better than center position. still room for twiddling. Freeway plus in town.

NEW TOPIC...the air correction jet is a mystery. As far as I can tell, its primary effect is on the main jet,so I have been told from knowledgeable sources. I leave it out entirely. If anyone can give the fine details of the A/C jet, please inform. I have never felt a difference whether I use a large one or a small one.

*** HELPFUL HINT: if you are having trouble removing the A/C jet, a shop vac works wonders. You can hear it rattling all the way down the tube.

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