Author Topic: slow acceleration to 1/4 throttle.......then WOW!!!  (Read 14621 times)

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kfthompson

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Reply #30 on: August 05, 2013, 03:42:11 am
Thanks, mine is on the bottom notch. Just wanted a reference point.


tooseevee

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Reply #31 on: August 05, 2013, 01:15:51 pm
Thanks, mine is on the bottom notch. Just wanted a reference point.

            If you have your slide needle clip in the bottom groove already (richest) & you still can't solve your "0-1/8" throttle problem with the mixture screw, then you're going to have to raise your slide needle with shims (one at a time). Then road test & tweak your mixture screw with each change you make.

             These tiny little shims are available at any Jap bike dealer with a good stock of Mikuni parts.

              I thought you said your slide needle had the hard plastic collar on it covering the e-clip grooves. And also I don't remember - are your exhaust & intake systems wide open? No restrictions?   
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


Superchuck

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Reply #32 on: August 07, 2013, 05:19:14 am
Looks like I'm going to have to pick up some shims tomorrow...

Thanks guys, this thread is great.  If I can figure out how to replace the pilot jet in my BS29 I'll be taking mine for its first test drive tomorrow after work.


tooseevee

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Reply #33 on: August 07, 2013, 01:31:30 pm
Looks like I'm going to have to pick up some shims tomorrow...

Thanks guys, this thread is great.  If I can figure out how to replace the pilot jet in my BS29 I'll be taking mine for its first test drive tomorrow after work.

           It's very simple to switch pilot jets with the carburetor removed.

           It's a little trickier with the carb left on the engine. You need a small mirror & a small, thin, regular slot screwdriver. The screwdriver must fit up into the tube the pilot hides in. You can't see the pilot jet slot with the carb on the engine. You can see the tube it's inside of with the mirror & then get the screwdriver in the slot by feel.

            If you (or anyone else) want an exploded diagram of the BS-29, I have one I can scan & post here. I just need time to rework the key to the parts. It's incorrect as printed.
« Last Edit: August 07, 2013, 01:33:52 pm by tooseevee »
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


Superchuck

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Reply #34 on: August 07, 2013, 02:49:38 pm
Thanks for the info and the offer of the diagram- I think I know what I need to do now.  I'll try and get the pilot in while it's mounted to the machine, but if I need to move the needle or add shims, I'll have to bring it inside somewhere clean and safe, right?


tooseevee

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Reply #35 on: August 07, 2013, 04:02:47 pm
Thanks for the info and the offer of the diagram- I think I know what I need to do now.  I'll try and get the pilot in while it's mounted to the machine, but if I need to move the needle or add shims, I'll have to bring it inside somewhere clean and safe, right?

           The first time I started the rejetting & needle height changing process I removed the carb totally because I wanted to learn about the whole thing & look at everything; the fuel line, the throttle cable mechanism etc.. I replaced the horrible stock fuel hose & gave it about an inch more slack.

           Now I can do everything without unhooking the fuel line OR the throttle cable. I just pull the carb from the manifold, turn the top slightly toward me & remove the two cap screws. Hold the cap as you remove the screws or the spring & the cap will end up on the floor.

            Now you can pull the slide out of the carb & take it wherever. The two tiny screws & hold-down for the needle are tricky the first time. Each successive time gets easier. A magnetic Phillips helps. I can't tell you how to do the needle hold-down & the tiny screws; only experience will do that. I felt like a monkey fucking a football the first time. Now? 5 minutes out & back in.

             Tilt the carb the other way & you can easily do the pilot & main jets (with a little neck twisting). I can do my pilot jet now totally by feel with the carb attached.

             Another hint: Lift the float & tape it up to the carb body with just a small piece
while you're doing all this so you don't accidentally bend something.

              Also note the tab on the neoprene slide diaphragm. I fits into its own slot on the carb body before the spring & cap go back on. This is what aligns the slide cutaway properly.

               The cap also has its own indexer; it's like a tiny open square on the edge of the cap that fits over a square lump on the carb body.  The cap won't sit down flat on the diaphragm unless it's indexed correctly on that lump.
« Last Edit: August 07, 2013, 04:16:32 pm by tooseevee »
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


DanB

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Reply #36 on: August 07, 2013, 04:37:34 pm
Quote
These tiny little shims are available at any Jap bike dealer with a good stock of Mikuni parts.

I ended up going to a True Value hardware store and found a number of very thin / small washers.  They work a treat!  I found them in the 'metric' section. 
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Superchuck

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Reply #37 on: August 07, 2013, 07:38:08 pm
Super helpful- thanks again!


Ice

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Reply #38 on: August 09, 2013, 05:11:32 am
 CV's are awesome ride a day carbys when set up decently. Very forgiving of seasonal atmosphere and altitude changes and very efficient at atomizing the fuel and mixing it with air.

 They can be modded for increased performance too.
http://www.indiancarsbikes.in/automotive-technology/crisp-punch-ported-throttle-slide-cv-carb-9399/
 
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tooseevee

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Reply #39 on: August 09, 2013, 01:23:29 pm
CV's are awesome ride a day carbys when set up decently. Very forgiving of seasonal atmosphere and altitude changes and very efficient at atomizing the fuel and mixing it with air.

 They can be modded for increased performance too.
http://www.indiancarsbikes.in/automotive-technology/crisp-punch-ported-throttle-slide-cv-carb-9399/

            Yup. The little BS-29 is a fine little tool now that I completely understand it & have fondled all its innards.

             I took an almost 20 mile ride Wednesday on some nice RI blue highways. It was one of those rare Colorado/Wyoming type RI days. Clouds & sky like that day are very rare here. The RE is running the best it ever has with its now totally open exhaust, K&N cone, 17.5 pilot & its slide needle & mixture appear to finally be at the "pretty damn close" place. It's just running incredibly well & I'll say again - I love this damn bike! It's like my 50 mile an hour Hoveround ("Where would YOU go?") & I don't feel like a crippled up old dinosaur when I'm on it + Medicare (the taxpayers) didn't buy it for me.

            My main jet is still stock (runs fine at 50/55 in both 4th & 5th) & after I pass 1,000 miles (at 810 now) I'll start cranking her all the way once in a while. I'll no doubt have to increase one or two sizes.

            Thanks, Ice, for the reminder. I've had that slide porting article bookmarked since I first saw it mentioned here a few years ago. I'll think about it after I've ridden a season on the rejetted main. My problem with it is it's immediately permanent. There's no going back.   
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


Superchuck

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Reply #40 on: August 09, 2013, 02:55:07 pm
Ice, have you tried that slide punch technique?  I remember you posting it a year or two ago.  For now, I'm in tooseevee's boat where I like the idea of all my mods being reversible back to stock.  If I mess it up, I can build it back to the way it was intended.


DanB

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Reply #41 on: August 09, 2013, 04:12:13 pm
I've actually done this, and the response from the throttle is noticeable.  Not a 'stellar' increase in performance, but responsive is the best word to describe it.

I was worried about messing with the only slide I had, so I ended up contacting the author in the article to order an additional slide.  If I recall, it cost about 11 USD + about 25 in shipping from India.  So I have 2 slides. 

One thing to note is that I believe as a result of this mod (I say believe, as I changed a whole number of things and cant be certain the slide mod is the root cause), is that my starting procedure really changed.  After rejetting, and opening things up, I couldnt start the bike either cold or hot consistently.  Before all my mods, I was kicking it easy with just choke.  Not so after the mods.  It acted like it was missing air.  So now, I hold the throttle at about 1/8 open on kicking over (which should be a no-no), and I get zero kick back and 1st kick starts; hot or cold.  You may not experience the same thing as each bike has it's own personality.  It works for me. 

Would I do it again?  Yes I would...  I like the CV carb, but would like a little more performance out of it between 1/8 and 1/2 throttle.  When I wack it open, it goes nicely!
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra


Superchuck

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Reply #42 on: August 09, 2013, 06:17:29 pm
Good to hear Dan,

I generally give a touch of throttle when kicking my current stock setup.  Not always necessary, but it definitely helps.  We'll see how it goes today.  I'm going to put in the 17.5 pilot and remove the hot pipe this afternoon.  I think I'll use the slide punch technique at a later date.  I want to get this thing set up real nice before changing things again.


tooseevee

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Reply #43 on: August 09, 2013, 06:37:10 pm
I've actually done this, and the response from the throttle is noticeable.  Not a 'stellar' increase in performance, but responsive is the best word to describe it.

I was worried about messing with the only slide I had, so I ended up contacting the author in the article to order an additional slide.  If I recall, it cost about 11 USD + about 25 in shipping from India.  So I have 2 slides. 

One thing to note is that I believe as a result of this mod (I say believe, as I changed a whole number of things and cant be certain the slide mod is the root cause), is that my starting procedure really changed.  After rejetting, and opening things up, I couldnt start the bike either cold or hot consistently.  Before all my mods, I was kicking it easy with just choke.  Not so after the mods.  It acted like it was missing air.  So now, I hold the throttle at about 1/8 open on kicking over (which should be a no-no), and I get zero kick back and 1st kick starts; hot or cold.  You may not experience the same thing as each bike has it's own personality.  It works for me. 

Would I do it again?  Yes I would...  I like the CV carb, but would like a little more performance out of it between 1/8 and 1/2 throttle.  When I wack it open, it goes nicely!

           Thanks for your above, Dan. Just for my future reference do you recall what size drill bit you used? I'll also get another slide before I do it. I should do that now. There can't too many of these things left.

            Mine is starting now in one or two kicks hot or cold with no enrichener & no throttle. Just turn the key on, kick it, it's running.

            I'll be interested to see what it does when it gets cold this Fall. 
« Last Edit: August 09, 2013, 06:40:03 pm by tooseevee »
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


DanB

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Reply #44 on: August 10, 2013, 04:17:59 am
Quote
Just for my future reference do you recall what size drill bit you used?

If I recall, I used an 1/8 inch. Basically following the article. I did use a drill press to keep it as clean and straight as possible. I definitely recommend getting a 2nd slide; cheap insurance :) good luck 2CV!
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra