289 carb settings

Hump3

Active Forum User
VOC Member
I have had the original 289 carbs sleeved (by MB) and am retro-fitting them to my '54 BS. I want to order new needles and MJs and could use some advise as to what combinations to go for.

As stands:

Front
Slide: 29/4
MJ: 190
NJ: 29
Needle: 29

Rear
Slide: 29/3
MJ: 200
NJ: 29
Needle: 29

Burlen sells their new 289s with 180 MJs and 106 (?) NJs.

Any advice much appreciated.
 

greg brillus

Well Known and Active Forum User
VOC Member
Main jet sizes seem ok, needle jets should be 106's and these are the part that wares, not so much the needles themselves. I would replace the Mains, needles and needle jets as a matter of course. I often find the number 4 slides on Shadow carbs to be a bit lean off idle, and often spit back until fully warmed up. I prefer to use the number 3 1/2 slide to help this, but sometimes they are hard to find, and as such I generally machine 30 thou off the bottom of the number 4 slides to fix this. A set of good aircleaners helps to richen the mixture as well.....Cheers for now......Greg.
 

chankly bore

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Non-VOC Member
I would go with tha above advice, anyway, how much running are you going to do on the mains and in what ambient temperatures? Altitude shouldn't be a big problem if you are in Japan.I am boldly assuming that is where Nogita is.
 

Hump3

Active Forum User
VOC Member
Much appreciated advice - thanks guys. I have ordered the relevant parts from Burlen.

Yup, Japan. I am a member of the club too but cannot seem to upgrade my forum status...

-Humphrey
 

Rob H

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VOC Member
Interesting I was just about to post about this. My carbs need a refurb and I was wondering if any members had any experience with Martyn Bratby and what his work was like?

I spoke with him and he said the carbs would be bored out with a new special made oversize /4 slide. I currently run 3.1/2 but note that the slides on yours are quite differnet with the rear being quite rich. Is that what was on or recommended to you?
 

Hump3

Active Forum User
VOC Member
Martyn Bratby has done work for me over the years and it's always been of the highest standard. These carb bodies were re-sleeved by him (my reference to "MB" in original post) but the slides were not matched from the start for some reason. In my haste I just removed the carbs and stripped them of all their gubbins before sending them to him without checking. Both slides have the same cutaways now but I should give Martyn a call to find out just what they are...

One thing - if you want to retain the original finish on your carb then you should tell him from the start - he does often sodium blast the exteriors.
 

chankly bore

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Non-VOC Member
There is anecdotal evidence that modern fuel burns hotter than the stuff we used to use- at least in Australia. Also, "silencers" are sometimes less restrictive. Both these points mean that you should be wary of No. 4 slides unless accompanied by an air cleaner. This observation is to be considered in line with the way you use the machine of course! By the way, always bore out your fuel cap breathers a little bigger on the top and underside!
 

Rob H

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VOC Member
Martyn Bratby has done work for me over the years and it's always been of the highest standard. These carb bodies were re-sleeved by him (my reference to "MB" in original post) but the slides were not matched from the start for some reason. In my haste I just removed the carbs and stripped them of all their gubbins before sending them to him without checking. Both slides have the same cutaways now but I should give Martyn a call to find out just what they are...

One thing - if you want to retain the original finish on your carb then you should tell him from the start - he does often sodium blast the exteriors.

OK thanks, will make a note. I am guessing your slides are /4 as he said he puts the carbs back to factory spec unless otherwise requested

regs
Rob
 

Hump3

Active Forum User
VOC Member
Well, I spoke with Martyn Bratby and he confirmed that he fitted /4 configured slides.

Replacing the slides is not an option as the carb bodies have been machined.

Taking on board the advice proffered that these slides will create a lean mixture with modern fuels, I am keen to learn what combination of MJ and needle (notch) setting list members recommend to use with these /4 slides. I have new 180, 190 and 200 MJs available and have fitted new needles and 106 NJs which arrived from Burlens this week.

I would like jetting and setting advice to run the carbs as follows:

(i) As-is, sans filters.
(ii) Fitted with filters (I have a pair of replicas Vokes).
 

Rob H

Well Known and Active Forum User
VOC Member
[/QUOTE] Taking on board the advice proffered that these slides will create a lean mixture with modern fuels, I am keen to learn what combination of MJ and needle (notch) setting list members recommend to use with these /4 slides. I have new 180, 190 and 200 MJs available and have fitted new needles and 106 NJs which arrived from Burlens this week.

I would like jetting and setting advice to run the carbs as follows:

(i) As-is, sans filters.
(ii) Fitted with filters (I have a pair of replicas Vokes).[/QUOTE]

I would be interested in hearing what other members run also. I assume we are talking about a standard motor, not big bore, hot cams etc..
Would not generally recommend running without filters though if you are going to use it regularly

R
 
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