Re: Whatcha got there??

[Bob Hadden <kbhadden@xxxxxxxxxxx>]

John,  Put me in for a yes vote for 'the rest of the story"!

Couple of questions.  Did you pull out the computer and extra parts?  
How much weight there?  How is the area around your feet with carbs 
right next to them?

Glad to hear you like the results.  Must have been a challenge to make 
this conversion, so the satisfaction of a job well done must be 
gratifying indeed!

Bob Hadden '05R12GS, '62R27

On Aug 30, 2005, at 10:08 AM, John Dancoe wrote:

> Clive cliddell@xxxxxxxxxx <mailto:cliddell@xxxxxxxxxx>  wrote:
>>
>>> Cees wrote:
>>>
>>>> could be a couple of Bings doing the work down there
>>>
>>> They ARE Bings.
>>>
>>> Mine aren't...anymore...
>>
>> John,
>> Whatcha got there??
>
> Hah! Someone finally took the bait.
>
> "Long-time list members" (who know my capability for extreme 
> verbosity), will
> appreciate this "succinct" report.
>
> "Long-time list members" know that:
>   (1) I have a long history of animosity toward Bing carbs
>   (2) I've always been disgusted with how reluctant my '93 R1100RS was 
> to
> start
>   (3) I've been threatening to replace my throttle bodies ever since I
> discovered they were Bings ("no wonder they go out of adjustment every 
> few
> thousand miles")
>   (4) My bike was running progressively worse for the past 3 years
>   (5) Early this year I conclusively determined worn throttle bodies 
> to be the
> cause
>   (6) About the same time, Tom Cutter reported "go-fast boys in Europe 
> getting
> 108 HP" from R1100Ss "with 41mm smooth-bore Mikunis"
>
> Replacing the throttle shaft in the RH throttle body helped with (4), 
> but
> since the shaft bore was visibly damaged it was no surprise that the 
> repair
> did not come close to restoring my bike's original performance. I 
> concluded
> that replacement of both throttle body assemblies was required.
>
> One possibility: buy a new set of Bing throttle bodies.
>
> In light of (1), (2), (3), and (6), I rejected that option.
>
> [There's a long and I think pretty cool story here; skipped for now.]
>
> I installed a set of 44mm Lectron "Power Jet" flat-slide carbs instead.
>
> My goals for measuring a successful conversion were relatively modest:
>
> A. The bike MUST start
> B. The bike MUST idle
> C. Performance MUST be comparable or superior to new
> D. Fuel economy SHOULD be comparable or superior to new (not actually
> expected)
>
> I now have 1,868 miles on the conversion.
>
> Note that I do not consider the tuning complete. In fact, the throttle
> twistgrip/cable assembly that I concocted needs another revision, 
> because I
> can't actually achieve WFO with the current assembly.
>
> But I am happy to report:
>
> A. The bike starts BEAUTIFULLY. I could not ask for better starting. 
> It really
> is exactly what I was hoping for, an order of magnitude better than it 
> EVER
> did before, and I am absolutely thrilled with this.
>
> B. The bike idles reasonably well, although not quite as smoothly as 
> the F.I.
> did when it was running right. In general, with carbs the engine seems 
> to have
> a bit more "attitude" (which could be a euphemism for "roughness") 
> than it did
> with F.I.
>
> C. Performance is indeed comparable. I don't know if it's as good as 
> new (I
> never dyno'd it so I'll never really know), but seat-of-the-pants says 
> my old
> friend, who was deathly ill for years, is BACK! I was able to hit 0-60 
> in
> approx 4.3sec vs. the original spec (IIRC) of 3.4sec. Note: that's a 
> bike with
> 75k miles on it,  7/8 throttle available at best, and me, eyeballing a
> wristwatch duct-taped to the triple clamp; NOT a professional test 
> rider on a
> new, professionally-tuned, blueprinted bike, with radar timing and
> instructions to "turn in the best possible time, even if you blow it 
> up in the
> process."
>
> The bike certainly has more power than clutch, I could smell that 
> after the
> first run. Top end is frankly poor, but I have not yet even attempted 
> to tune
> in that range (I don't spend much time there), and as noted above, I 
> can't get
> WFO with the current cables/twistgrip anyway so what do you expect.
>
> D. Fuel economy is comparable. On a couple restrained freeway rides, 
> I've hit
> 42 mpg, which is actually as good as I ever actually recorded with F.I.
> (though I think I've done better on occasion). In day-to-day riding, I 
> have to
> admit economy has suffered about 8% (165 miles to low fuel warning, vs 
> 180).
> However, my last plug checks indicate it is still running rich.
>
> Also, I suspect 44mm is probably bigger than a carb should be for this 
> motor;
> I'm sure I'm losing intake velocity and economy that I'd have with a 
> smaller
> bore (like say 41mm). But 44mm was the closest match that Lectron had
> considering overall geometry.
>
>
>
> IN CONCLUSION: COLOR ME HAPPY.
>
>
>
> If you would like to hear the whole, sordid story (which I warn you is 
> 30
> years in the making), let me know and I'll finish writing it and send 
> it to
> you off-list.
>
> If the LIST would like the looooooooong story, have a vote; I think it 
> would
> actually be in the very best spirit of why this list exists in the 
> first
> place. But I won't expend the bandwidth without a few nods.
>
> Regards,
>
> John Dancoe AKA "Manfred von Blitz"  '93 R1100RSxABSxFI AKA "Nada 3"
>
> p.s. I'm not selling kits at this time, and until I have a lot more 
> miles on
> this project I would not recommend anyone following my lead. But I am
> considering making kits available and if you are interested, let me 
> know. As
> far as I know, I'm the only person in the USA to have done a carb 
> conversion
> on an Oilhead, and probably the only person in the world to have done 
> it with
> Lectrons. Also note: I think that Dell'Ortos or Mikunis would probably 
> be
> excellent choices. I close Lectron based on favorable past experience 
> on dirt
> bikes, and the likelihood that proper jetting would be much more
> time-consuming to accomplish with other makes.

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