Carb Pumps
- Thread starter Twosheds
- Start date
piranha-bro2
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- Melbourne
Buon compleanno, Augusto! Auguri! 
Std spec FRCs don't come with choke, but the ones fitted to early GSX-Rs did have a choke/enriching sys.
My two are linked by tubes across the float bowls. The one Lee swapped for my plain one was so I can have a pump for each pair (mine came off a four cyl so only one pump for the bank of four). I had to drill and fit a brass tube from the blank float bowl ... tricky job, lining up with the internal cavity.
You can see the lever on the carb in the pic - I've since moved the pivot point and plunger pin point altered the pull ratio to give more swing at the thumb lever (and clear the intake tubes that weren't fitted when i made the bloody thing!!).
The thumb lever started as a SRAM bicycle shift lever (broken mechanism). Insanely highly engineered thing with the lever running on two miniature roller bearings!! Was tricky making the housing for the cable fitment and getting it to sit neatly under the LH switch block. Worked out well in the end. Another eg of the ludicrous amount if time I'm spending on this bloody SFQ!!
Std spec FRCs don't come with choke, but the ones fitted to early GSX-Rs did have a choke/enriching sys.
My two are linked by tubes across the float bowls. The one Lee swapped for my plain one was so I can have a pump for each pair (mine came off a four cyl so only one pump for the bank of four). I had to drill and fit a brass tube from the blank float bowl ... tricky job, lining up with the internal cavity.
You can see the lever on the carb in the pic - I've since moved the pivot point and plunger pin point altered the pull ratio to give more swing at the thumb lever (and clear the intake tubes that weren't fitted when i made the bloody thing!!).
The thumb lever started as a SRAM bicycle shift lever (broken mechanism). Insanely highly engineered thing with the lever running on two miniature roller bearings!! Was tricky making the housing for the cable fitment and getting it to sit neatly under the LH switch block. Worked out well in the end. Another eg of the ludicrous amount if time I'm spending on this bloody SFQ!!
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Dellortoman
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- Location
- Tasmania, Australia
Probably a dumb question, but why would you buy a carby with no choke, then re-purpose the accelerator pump as an enricher device for starting?
A choke button (opens an enricher jet) is an option on Keihin FCR carbs.
A choke button (opens an enricher jet) is an option on Keihin FCR carbs.
There is a huge thread on Adventure Rider on this same subject re FCRs on KTM twins, the lengths this bloke went to adapt a choke system was Insane. But he had big issues getting easy starting when cold. I don't think he ever achieved it, from memory he fitted a later Injections system and then built a turbo setup after teaching himself to TIG and finally adapted a Christian Two-wheel drive setup. His homemade exhaust was pure art in the end. I wish I could still find it was its a crazy read, maybe a 1000 pages long
Tippie
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- Dr?bak, Norway
"A choke button (opens an enricher jet) is an option on Keihin FCR carbs."
I haven't yet found a supplier for FCR bits that doesn't charge eye watering prices. The mob in Adelaide are a good example. For me just a quick squirt from just the rh carb is too easy to bother any alternative, and only needed if it was dead cold. Without it the bike will not start, (and I reckon that is what saved me for permanently losing it when it was stolen, the thieves had spun it over so much that in the end the starter clutch went round and the battery was flat, they had got it going in the end though as it was abandoned at junkie headquarters in Oslo where they buy their dope, there were people shooting up a few metres from the bike and cops a few metres further off, ignoring it all, the bike on their stolen register, I just loaded it on a trailer and drove home).
I haven't yet found a supplier for FCR bits that doesn't charge eye watering prices. The mob in Adelaide are a good example. For me just a quick squirt from just the rh carb is too easy to bother any alternative, and only needed if it was dead cold. Without it the bike will not start, (and I reckon that is what saved me for permanently losing it when it was stolen, the thieves had spun it over so much that in the end the starter clutch went round and the battery was flat, they had got it going in the end though as it was abandoned at junkie headquarters in Oslo where they buy their dope, there were people shooting up a few metres from the bike and cops a few metres further off, ignoring it all, the bike on their stolen register, I just loaded it on a trailer and drove home).
piranha-bro2
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- Melbourne
Dellortoman said:
Cos I bought them for their super accurate carburation, nothing else. As the Tipmeister says it only takes a squirt in all weathers to fire the bike up - and that's with only one carb/cylinder. I have been offered bodies from the 'road' version, with choke galleries all open and a proper choke system, but at this stage I don't think I need to do all that faffing around. Obviously Suzuki didn't want to sell a bike where you basically relied on squirting the throttle to start it. No 'pull choke' to be seen on my FCRs.
Dellortoman
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- Tasmania, Australia
OK. Reading between the lines, I'm guessing you got the carbs 2nd hand and took what you could get. If buying new, you could choose them with a cold start circuit.
Tippie
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- Location
- Dr?bak, Norway
If the choke button was easily accessible. Mine were bought new and fitted to an SF. The expert setting them up told the owner that they couldn't work properly as the 39mm was too big and impossible to tune to an SF, so he sold them to me and bought smaller ones. I set them up as good as I could ever want a carb to be, I don't know what the problem was. We are way off discussing pumps on Dells though.
CLEMTOG
Hero member
back to Augusto's pumps and a belated happy birthday to him.
Perhaps the three or four micro squirts of juice was enough to dull the plugs to be semi unresponsive state for a nano second when walloped in first or second out of the corner.
CLEM
micro= tiny
semi = almost zilch
nano = nothing at all really
walloped = big handful
Perhaps the three or four micro squirts of juice was enough to dull the plugs to be semi unresponsive state for a nano second when walloped in first or second out of the corner.
CLEM
micro= tiny
semi = almost zilch
nano = nothing at all really
walloped = big handful
piranha-bro2
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- Location
- Melbourne
Dellortoman said:
Basically, I've never really been able to afford FCRs. But about 25 years ago a bank of four horizontals (as against the Yamaha downdraught type) came up for sale for about $800 or $900 in the good ol Trading Post. From a Suzuki GSX-R1100 IIRC. The guy posted them down from Sydney in an Oz Post box that reeked of petrol fumes!! No way today, Jose!
Anyways, turning 1x4 into 2x2 was no easy feat, cos the four only had one cable mechanism, one spring, one long hard-chromed throttle shaft, one pumper and one idle speed stop screw ... oh, and no choke!
Plus a load of other things like fuel pipes, breather tubes and T-joints or L-joints that didn't suit the SF cylinder spacing. Came together after much thought and playing on the lathe and ... I found that Wemoto in Japan can source virtually every part on them, and their prices are probably half those of the rest of the world. FCR stuff is hellishly expensive (for a mere peasant like me anyway). Four new needles, various assorted jets, o-ring sets, springs and the like were shipped to me a few years back, so hopefully I have everything I need. Two pairs of twin FCRs new would set me back a shaez load more than I've spent. I'd love to be independently wealthy but I'm an old Laverda punk who got their bike back in the 70s when a young Laverda punk could own and maintain them on a pauper's wage. These days the dough mostly goes to running the family of four.
Dellortoman
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- Tasmania, Australia
Piranha Brother 2 said:
Yep. I turned 3 individual RS36 carbs into a set of 3 for a Laverda triple. They were the #4 carbs that Red cuts off the set made for Japanese 4 cylinder bikes when he creates the triple carb banks. They were all the same 'hand' with bearings in the wrong place, no pump, missing a bunch of the linkage parts, etc. Fiddly job but as I couldn't afford a new set on my retirement wage, it was worth the time spent.
Take a page out of Monty Python's Meaning of Life: Sell the children for scientific experiments.
piranha-bro2
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Absolutely love that Monty clip - even moreso the one where she drops a newborn on the floor while toiling at the laundry sink and says to the daughter, 'Get that will you, dear'. Total gold.