Mikuni RS36 carbs

murphus

murphus

Senior member
Location
Lost in the Midwest
Will check the mounts. Had the engine out a few years back and pretty sure I haven't checked since. And yes, carbs, I've been pondering switching to Mikunis. I've always had this thing about originality, but it can get in the way of actually riding and enjoying the machine. What/who is the best source for carbs and attendant cables, etc.?
 
murphus said:
Will check the mounts. Had the engine out a few years back and pretty sure I haven't checked since. And yes, carbs, I've been pondering switching to Mikunis. I've always had this thing about originality, but it can get in the way of actually riding and enjoying the machine. What/who is the best source for carbs and attendant cables, etc.?
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I am not overly into the originality thing but I thought I should stick up for the old Dells!
I have no doubt Mikunis will provide better fuel consumption and smoother fueling however the Dells on my series 2 operate very well and do not need constant attention.
Admittedly I live in a warm clime, but it is choke on, starts quickly, choke straight off and away we go.
Tick over around the 1,000 revs very constant and actually even a couple of days ago I had to stop just after I took off and was amazed the bike just kept idling before fully warmed up at just over 500revs indicated. (quickly got moving again or I would have turned it off)
Haven't touched the carbs in ages.................
I get close to mid forties mpg but obviously will drink much more the further up the rev range.
Last set of plugs I changed were in for about 22,000kms. Only plug fouling problems I used to have was with original ignition! (Also had significantly worse fuel consumption on original ignition)
I had thought about Miks a number of years ago and had queried Red, but exchange rate had beaten me at the time and didn't seem worth it considering current set up operates well.
I think regular riding keeps most carbs problems at bay (although I am riding the triple less now in favour of the 750....)
Anyway, just thought I'd say, not all Dells are clogged up heaps of problems.
 
But in two bikes RGS and SFC I am using the Dellortos and with new inner items and a good adjustment I am happy with them. Costs were about 100€ to refurbish them, not 600!, and the consumption now is about 6-6.5 l/ 100k. It also surprised me. Usualy I had to fill new petrol after 200k, but in my way to Breganze after 250k just 14.? liters ????
 
andre g said:
But in two bikes RGS and SFC I am using the Dellortos and with new inner items and a good adjustment I am happy with them. Costs were about 100€ to refurbish them, not 600!, and the consumption now is about 6-6.5 l/ 100k. It also surprised me. Usualy I had to fill new petrol after 200k, but in my way to Breganze after 250k just 14.? liters ????
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Andre, it is about 100€ just for the parts (new jets and seals - minimum maintenance, not a repair really...). If the bronze bushes are worn, the sliders are damaged (and there is a fair chance that with 75.000km, that is the case...), sometimes even the actuation rods that sit in the "dome" of the carb and connect to the next carb body for equal actuation are worn out, need welding, polishing and re-chroming etc., 600€ can easily be the price if you give it into professional hands like OCT... Keep in mind this takes a lot of hours...

Just pulling them apart, throwing them into the ultrasonic bath, washing them clean, drying them with pressurized air, re-assembling them with all new jets and gaskets etc. takes about 3 hours, wich equals to 240€ plus parts => 340€. Now imagine you need new sliders... all new sliders need re-working - another 30 minutes at least plus parts => 150 € => 490€. Add new acceleration pump membranes to it and some other parts and the 600€ are not far away... And then you still might have carbs that are not working as intended (happened to several people...)

If you can do all that on your own, you might end up with less than 250€ for a full restoration. But who can do re-bushing the domes f.e. on their own, please...?
 
Laverdalothar said:
Andre, it is about 100€ just for the parts (new jets and seals - minimum maintenance, not a repair really...). If the bronze bushes are worn, the sliders are damaged (and there is a fair chance that with 75.000km, that is the case...), sometimes even the actuation rods that sit in the "dome" of the carb and connect to the next carb body for equal actuation are worn out, need welding, polishing and re-chroming etc., 600€ can easily be the price if you give it into professional hands like OCT... Keep in mind this takes a lot of hours...

Just pulling them apart, throwing them into the ultrasonic bath, washing them clean, drying them with pressurized air, re-assembling them with all new jets and gaskets etc. takes about 3 hours, wich equals to 240€ plus parts => 340€. Now imagine you need new sliders... all new sliders need re-working - another 30 minutes at least plus parts => 150 € => 490€. Add new acceleration pump membranes to it and some other parts and the 600€ are not far away... And then you still might have carbs that are not working as intended (happened to several people...)

If you can do all that on your own, you might end up with less than 250€ for a full restoration. But who can do re-bushing the domes f.e. on their own, please...?
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I can partly agree with you on the cost of parts Lothar.
As for the rest, the average competent classic motorcyclist should be capable of the work.

Paul
 
Paul Marx said:
I can partly agree with you on the cost of parts Lothar.
As for the rest, the average competent classic motorcyclist should be capable of the work.

Paul
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I can replace parts, but I can not repair them. That takes several tools (Lathe, Press etc.) and knowledge I don't have (and many others also don't obviously, else we wouldn't see as many questions regarding carb-Issues as we do...) ;-)
 
Laverdalothar said:
I can replace parts, but I can not repair them. That takes several tools (Lathe, Press etc.) and knowledge I don't have (and many others also don't obviously, else we wouldn't see as many questions regarding carb-Issues as we do...) ;-)
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Knowledge can be acquired, as can tools.
Both thoroughly recommended if one rides antiques.

Paul
 
I've been down this road before with the Bings on my '73 R75/5, which now sports about 84,000 miles. And it was at about the same 75,000 miles that I replaced the Bings with VM Mikunis. I'd thoroughly rebuilt the Bings, but could not get satisfactory performance. Installed the Mikunis and never looked back; they work beautifully. I'm with Lothar on this one. I could spend an inordinate amount of time and yes money to not actually gain much because of limitations in what I can do. Or just start over.
 
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I went and looked at the Topham site and their VM kit is quite intriguing. I see that the set will fit the OEM rubber intake spigots, but will they also fit the air box spigots? I ask since every time I have used K&N filters the intake roar has increased dramatically. This may not be an issue on a Jota, but, for me, it would be with my Executive. I like the sound of a strong exhaust, but not a loud intake roar.

Also, would I be correct in assuming that they come with the jetting in the ballpark, so I would have a good starting point for fine tuning?
 
Laverdalothar said:
Buying a lathe and press to fix the carbs is not worth the money I feel... However, each to their own... ;-)
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You need neither for the carbs on a triple, however, the financial argument just doesn't do it. We both have several bikes that we don't need to work or eat and which cost a lot of money to maintain. We need a lot of space to stock the machines and that costs a lot of money, not to mention the insurance, riding gear etc... So, a lathe, a press, a bench drill, a milling machine, which will cost a lot less than having bikes repaired and maintained by professionals, is money well spent. Not to mention money spent on a stupid car.

Paul
 
Paul Marx said:
You need neither for the carbs on a triple, however, the financial argument just doesn't do it. We both have several bikes that we don't need to work or eat and which cost a lot of money to maintain. We need a lot of space to stock the machines and that costs a lot of money, not to mention the insurance, riding gear etc... So, a lathe, a press, a bench drill, a milling machine, which will cost a lot less than having bikes repaired and maintained by professionals, is money well spent. Not to mention money spent on a stupid car.

Paul
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One of these days I'll actually get my lathe working. 1947 South Bend 9A. Doesn't have quick-change gears but otherwise a lovely old piece in good condition with both 3- and 4-way chucks. I need to take it apart, clean it, and put it back together properly oiled. One of these days ...
 
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Alzero said:
I went and looked at the Topham site and their VM kit is quite intriguing. I see that the set will fit the OEM rubber intake spigots, but will they also fit the air box spigots? I ask since every time I have used K&N filters the intake roar has increased dramatically. This may not be an issue on a Jota, but, for me, it would be with my Executive. I like the sound of a strong exhaust, but not a loud intake roar.

Also, would I be correct in assuming that they come with the jetting in the ballpark, so I would have a good starting point for fine tuning?
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I don't have air-filters installed on mine so I can't tell if they fit 100%, but I think I saw several with Mikuni and original rubber connectors (to be confirmed by others, please).

The jetting is close but depends a bit what you have (which cams, ccm, etc.) There is some knowledge on this forum that might be shared if you kindly ask. Else, anyone with Experience with Mikunis should be able to set them up
 
I asked Red about his setup. Comes complete with intake stubs, filters, cables, the lot. Intakes angled to keep carbs flatter, certainly would help relative to tank clearance and otherwise they're running at the extreme of their spec relative to mounting angle.
 

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murphus said:
I asked Red about his setup. Comes complete with intake stubs, filters, cables, the lot. Intakes angled to keep carbs flatter, certainly would help relative to tank clearance and otherwise they're running at the extreme of their spec relative to mounting angle.
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Lovely but I'm trying to keep from itching too much.

Paul
 
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