JS Motorsports Carbs

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Carbonfibre said:
The primary reason Anal carbs go out of sync is that as the carbs wear very rapidly (with the exception of those fitted to bikes whose owners claim 500,000 miles with no problems!), and not at exactly the same rate, frequent adjustments will be required to compensate for this wear.
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Hang about, just what aspect of synchronisation are we talking about here? To me, it is simply the synchronisation of the raising/lowering of the slides. The actual pilot air adjustment is done individually of course. So "wear", unless it is wear of the cable ferrules or adjusters, which is negligible, will not affect synchronisation. Actual tuning of mixture will of course be affected by slide wear, eventually, but I don't think that really happens as quickly as accepted internet wisdom would have it. Of course, I may be proved wrong within the next couple of years, we shall see. Use of vaccum gauges will probably show that up as an inconsistency which cannot be compensated for with mechanical adjustment.
 
ranmar850 said:
Carbonfibre said:
The primary reason Anal carbs go out of sync is that as the carbs wear very rapidly (with the exception of those fitted to bikes whose owners claim 500,000 miles with no problems!), and not at exactly the same rate, frequent adjustments will be required to compensate for this wear.
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Hang about, just what aspect of synchronisation are we talking about here? To me, it is simply the synchronisation of the raising/lowering of the slides. The actual pilot air adjustment is done individually of course. So "wear", unless it is wear of the cable ferrules or adjusters, which is negligible, will not affect synchronisation. Actual tuning of mixture will of course be affected by slide wear, eventually, but I don't think that really happens as quickly as accepted internet wisdom would have it. Of course, I may be proved wrong within the next couple of years, we shall see. Use of vaccum gauges will probably show that up as an inconsistency which cannot be compensated for with mechanical adjustment.
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Most people get confused over the fact that poor running caused by worn out Anal carbs is not something that can easily be cured by synchronising their worn carbs. Depending on specific use, wear in these carbs will be in the area of the carb body, which will lead directly to throttle slide wear. When body and slide are worn, this will mean the needle and needle jet will also be badly worn. In effect as the carbs do not wear evenly it will be necessary to adjust each carb differently to compensate for different amount of wear side to side. Of course this does not apply to those lucky enough to have aluminium rather than pot metal Amals, but have seen very few of these and they are certainly not available nowadays.
 
Well, i think that after all the discussion, i have decided to go with the JS Motorsports carbs. I guess that if I have any trouble fine tuning them, I can always swing by my local cycle repair shop, Flying Tiger Motorcycles and have Eric give me a hand. Thanks to all of you guys for taking time to share your experiences and opinions. I will certainly post back with my results.
 
rpatton said:
xbacksideslider said:
As for fuel lines, still working on it. Retaining the Reserve function of right petcock is important, so for me that dictates the configuration and I wish I could find a 4 way Tee that was not an similar to an X but more like two Ts - like this TT - to place in the center of the run between the two petcocks.
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Been thinking along the same lines, would like to have a fuel filter too. Maybe a set of 90deg elbows off the petcocks to a connecting hose with a tee in the middle to a 1 inlet/2 outlet filter from Pingle. They say they're "Super Short", the question is whether they're short enough and if there's enough room. It wouldn't be difficult to change the inlet to a tee, if it came down to it.

http://www.pingelonline.com/powerflo.htm

JS Motorsports Carbs
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This has me thinking... I wonder if you could use the pingel 2 inlet/2 outlet. Take your two lines off of both petcocks to the two inlets. Then simply connect the two outlets to each carburetor. Seems pretty easy.
 
I just got an e-mail from JS Motorsports saying that they may have shipped me a Carburetor kit with damaged choke assemblies.... the saga continues. The thing that is frustrating me at the moment is that these are an X-Mas present and I can't open the box until 12/25 to check. If I had any hair, I'd be pulling it out. :)
 
Johnnymac said:
I just got an e-mail from JS Motorsports saying that they may have shipped me a Carburetor kit with damaged choke assemblies.... the saga continues. The thing that is frustrating me at the moment is that these are an X-Mas present and I can't open the box until 12/25 to check. If I had any hair, I'd be pulling it out. :)
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I emailed everyone saying that its possible that a couple carbs went out (in the last month or two) with a choke problem (check if each choke actually runs rich). I'm asking you to check - that's all. Don't freak out. Its easy to fix and its no big deal. So take a few deep breaths and relax.
 
I've responded to some threads on this discussion by shortening the aircleaners so they should fit everone's backing plate (and not just some). See the clean cut on the rubber boot and the new narrow clamp below. Also note that the cable is buried over 3/8" deep in the adjuster and is very secure.

JS Motorsports Carbs
 
jseng1 said:
Johnnymac said:
I just got an e-mail from JS Motorsports saying that they may have shipped me a Carburetor kit with damaged choke assemblies.... the saga continues. The thing that is frustrating me at the moment is that these are an X-Mas present and I can't open the box until 12/25 to check. If I had any hair, I'd be pulling it out. :)
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I emailed everyone saying that its possible that a couple carbs went out (in the last month or two) with a choke problem (check if each choke actually runs rich). I'm asking you to check - that's all. Don't freak out. Its easy to fix and its no big deal.
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Thanks Jim. My frustration comes from the fact that the carbs are sitting wrapped up in a box under a christmas tree.... I can't open the box to verify that they are good or bad until 12/25.... If there is an issue, then I may have to wait even longer. I do appreciate your honesty and being proactive - letting me know. Hopefully they are fine.
 
hi Jim, does that apply to the two you sent me as there is no email regarding that in my in box?
Whats the fix if it does apply?
How did you cut down your air filter boots?
Regards Mike
 
You know with all this crap about these carbs and all the negative reports I am still gonna get me a pair mostly because Jim has been monitoring this post and replying with answers to everyones worries.
Good going Jim.
Problem is unlike Johnnymac who already has his set, I'll have to wait until after Christmas to get mine. Bah humbug
 
Johnnymac said:
This has me thinking... I wonder if you could use the pingel 2 inlet/2 outlet. Take your two lines off of both petcocks to the two inlets. Then simply connect the two outlets to each carburetor. Seems pretty easy.
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I was thinking that too, if there's enough room front to back for the hoses to make the turn into the front of the filter without kinking. From the pictures on Jim's site there seems like there might be. What I was thinking about doing is taking the center barb on a brass tee down to a threaded tube then tapping some threads into the cover and silver soldering or brazing it on. It would be a TT configuration and with the 90deg elbows on the petcocks I think space wouldn't be a problem and the hoses would have a straight shot to the filter. There is no partition between the paired inlets or outlets.
JS Motorsports Carbs
 
Brooking 850 said:
hi Jim, does that apply to the two you sent me as there is no email regarding that in my in box?
Whats the fix if it does apply?
How did you cut down your air filter boots?
Regards Mike
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I go through a check list for every carb (float height, needle setting, idle speed screw modification etc) and I recently added a couple items to my list that I didn't check before. I now check the choke circuit to make sure nothing is plugged. So I asked everyone to check that their chokes are working. I don't know of anyone who actually has a choke problem and no one has reported one. I'm being a little over cautious and careful because I want everyone to have a good experience with my products. I didn't email you Mike because I think I made the check on yours.

I hope Johnnymac takes the time to report that his carbs are also working fine when he gets them running.

Mike - I made a mount on my lathe to hold the aircleaner boot, clamped a sharp utility blade to the cuttoff tool - presto - a clean cut in seconds that shortens the boot nearly 1/4"
 
I checked mine today and the choke is fine. I will not be able to instal them until after the holidays though. I will certainly report back!
 
Johnnymac said:
In my quest to find the best carb setup for my bike, I spoke to Matt at CNW. I explained that I was looking at either the Mikuni, the JS Moto, or Dual Keihins. He was very nice and informative and recommended the Mikunis (I didn't even realize that CNW sold the Mikuni Kit) He explained that on the Dyno, the Mikuni has more power on the low to mid end compared to even his the Dual Flat Slide Keihins ( and as such, I would guess the JS Carbs) He explained the the 2 into 1 produces more torque which is why Jim Comstock uses the 2 into 1 for his fuel injection system. He said that he couldn't compare them to the JS Carb because he has not personally run them. He did acknowledge that the Mikunis were certainly not the best in the high end rpms, but that a lot people usually run in the low to mid range.

I would like to address the power issue a bit. I have never seen a case where a single carb on the commonly available manifold increases the torque at low engine speed over a well set up pair of stock carbs. Maybe equal - up to around 4000. Normally smoother.

Of course well set up stock carbs are seldom seen and hard to keep that way for very long. A single Mikuni is easy to live with and smooth in operation. Maybe the new Amals will be better than the old ones. I haven't tried JS carbs yet.

The reason I went to a single throttle body with my fuel injection was I found that with a good manifold I could make as much power as I could with twin throttles . Since my throttle body is very short in comparison to a carb and also very large in diameter it gives me a lot of freedom to design a good flowing manifold. Simplicity and easy fit of the single EFI body makes it the winner- so far. Jim
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Thanks JS for the feed back and info on the choke and shortening the filter boot.
Just a shame I am not at home to enjoy the extra 'oomph' they give!!!
In a shipyard on the north side of Singapore for $1miilion of repair as we got hit by an errant tanker late last week!!!!
Regards Mike
 
Brooking 850 said:
Thanks JS for the feed back and info on the choke and shortening the filter boot.
Just a shame I am not at home to enjoy the extra 'oomph' they give!!!
In a shipyard on the north side of Singapore for $1miilion of repair as we got hit by an errant tanker late last week!!!!
Regards Mike
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Oh yea? You think you have problems. Well tomorrow's trash day around here. How am I suppose to deal with that? And if that wasn't bad enough, it comes every effing week!

Just kidding, life should be so exciting, like over thinking wheel offset.

Any way, as far as the carbs go, they seem to be the best option to date.
TO REDLINE AND BEYOND!
 
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