pcnsd
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Posts: 113
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Post by pcnsd on Sept 29, 2008 20:49:27 GMT -5
Has anyone experience with the Edelbrock QwiksilverII pumper carbs and an opinion to offer? I am considering the 40mm unit for my SR. They appear to be an updated Lectron design.
Thanks
PC
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Post by caferacercarl on Oct 6, 2008 3:01:32 GMT -5
Am just pulling one off a flat tracker to fit a Dellorto 40mm on, will post Dyno charts etc, on the new website soon, and photo's.
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pcnsd
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Posts: 113
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Post by pcnsd on Oct 6, 2008 23:43:47 GMT -5
Thanks for your response Mr. Batey. I have a few months before I need to make a final decision. I had noticed these are a popular mod on Harleys and some modern singles like the XR, YZF, etc. When I checked feedback at other forums... well... its mixed particularly with the Harley crowd. I ran a Lectron carb on a previous 2 stroke short tracker. It could be tuned to run like heck wide open or part throttle but never really did both well. I ultimately returned to the VM38.
Thanks again
PC
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Post by solo2racr on Oct 7, 2008 0:56:14 GMT -5
I'm not really familiar with this particular carb but from looking at an exploded view of it, it's fuel metering system is almost identical to the older blue colored Lectron carbs. From what I remember about those, they were a pain to tune. In theory, a single metering circuit will work better than multiple ones overlapping each other. In fact, it does. The problem lies in the fact that engine do not consume fuel in a constant linear fashion. Depending on the engines state of tune, fuel demands will vary from engine to engine, even of the same type, at a given RPM and load. The tuning problems lay in chasing needle positions and tapers to work at all RPM's. Once you get it metering fuel correctly at the higher RPMS and loads for example, you end up still having to change the needle to get the low end working. On the plus side, if you are the patient type and like to fiddle with things like this, once you DO get it dialed in, the results can be very rewarding.
FWIW........Eddie Lawson's tuner back in the days before he went GP racing was Rob Muzzy. The two of them decimated the competition on a KZ1000 Superbike equipped with a bank of 4 Lectron carbs
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Post by caferacercarl on Oct 19, 2008 2:12:19 GMT -5
Trouble is ...no pump. they work well on high intake vacuum engines like Harley's [ rev limiter 5,200 std] but the more complex the carb the nicer the "carburration" at all throttle openings and the easier to ride smoothly at partial throttle openings, the primitive carbs work fine at full throttle, its the partial stuff that separates the whole lot of them, FCR's are magic! but dear..... [ 1,200 in Aussie]
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Post by StewRoss on Oct 24, 2008 2:46:30 GMT -5
Are these the type of carbs you are referring to?  ...Hmm, perhaps these are an earlier version, bit like the carbs on my Honda 350 racer. These ones are on Fast Freddie's CB750 Honda superbike... SR  |
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pcnsd
Full Member
Posts: 113
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Post by pcnsd on Oct 24, 2008 22:05:17 GMT -5
Those are an earlier version without the accelerator pump which comes off the throttle cable bell-crank assembly on the newer models. They may also be the pre-Edelbrock version carburetors. Edelbrock purchase QuikSilver in about 2002 (I think.) Good looking carbs, but do they work good? I am beginning to lean toward a FCR from the 2001-2002 YZ426F as a starting point.
Thanks,
PC
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Post by StewRoss on Oct 25, 2008 2:45:13 GMT -5
Spencer went to these carbs after having difficulty with the Kei Hins the race bike came with from RSC as I recall. They raved about them at the time. These would have gone on in the late '70s early '80s. They have 'ticklers' on the bowls and no choke setup. like the Kei Hin CRs they replaced. Personally the only US carbs I've seen used here in any numbers were the Lectron Powerjet and EI (Blue) carbs. Some liked them some hated them and blamed them for throttles sticking wide open etc.  I almost bought a Lectron PJ for my YZ465 many years ago, but changed my mind after the negative publicity and used a 38mm PJ Mikuni from a TZ instead. I eventually used both the TZ carbs and still have one on my Black Cafe Racer with the PJ blocked off. Great carb. I have a set of the Kei Hin CR carbs on the Honda 350 racer I have. Beautiful carbs...bearings on the shafts and all. The FCRs are a step above the roundslide CR carbs, and as I have one now I can start to experiment with it on the SR. All Kei Hin race carbs are 'works of art' as carbies go in my opinion. Sorry if I got off the subject...ahem...it's just that I love the CR carbs in all forms... SR  |
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