Vacuum
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Cruiser
Joined: Jun 2005
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Vacuum
TCSTD,
Thanks for update on Dyno kit compared to 2 washer spacing given on another thread. I am experiencing occasional carb coughing at low speed throttle,probably due to the spring and drilling the slide you said would happen . Since I already drilled the vacumn slide how do I compensate. Do I put the stock spring back or what??? How do I get the slide from not being so responsive giving me a lean position.Also should everything go back to stock like the tube, high speed jet etc .before I put the 2 washers under the stock needle and adjust the low speed mixture? I can put everything back to stock but the larger hole in the slide
Thanks for update on Dyno kit compared to 2 washer spacing given on another thread. I am experiencing occasional carb coughing at low speed throttle,probably due to the spring and drilling the slide you said would happen . Since I already drilled the vacumn slide how do I compensate. Do I put the stock spring back or what??? How do I get the slide from not being so responsive giving me a lean position.Also should everything go back to stock like the tube, high speed jet etc .before I put the 2 washers under the stock needle and adjust the low speed mixture? I can put everything back to stock but the larger hole in the slide
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Joined: Nov 2005
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RE: Vacuum
Why did you drill the vacuum port on your slide? Thats not a good thing to do, totally uneccsary, and you probably have permanently messed up the response curve of your carb. Also, I am aware of the washer under the needle trick, but again its a backyard way of trying to get your af mixture correct through the lower midrange. Best thing to do is get a proper needle with the proper taper. I have had to correct my fair share ov CV carbs from people doing these things. None of them work well over a broad range. A/F ratios will still have a wave effect of being too rich in one area and leaning out in another due to a poor needle, slive vacuum match.
Best thing to do is to get your slow jet dialed in first going with the smallest jet you can giving you an afr around 12.5-13:1 at idle, then finding the correct needle taper( www.woodcarbs.com has excellent CV carb needs that give super flat a/f response for very easy tuning and maximum power )profile in combination with an UNMODIFIED vacuum slide. With the main jet being set up and tuned last.
If you want it done right with no odd carb abnormalities(like decel or carb popping)whatsoever, you will go this route.
Best thing to do is to get your slow jet dialed in first going with the smallest jet you can giving you an afr around 12.5-13:1 at idle, then finding the correct needle taper( www.woodcarbs.com has excellent CV carb needs that give super flat a/f response for very easy tuning and maximum power )profile in combination with an UNMODIFIED vacuum slide. With the main jet being set up and tuned last.
If you want it done right with no odd carb abnormalities(like decel or carb popping)whatsoever, you will go this route.
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Joined: May 2005
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RE: Vacuum
Dick
The coughing is no doubt like I said due to the drilling of the slide and the weaker spring also. It causes the slide to raise too fast, and at a slower RPM, this is where the problem happens. You could try replacing the stock spring and it should help here. Only other suggestion is replace the slide. I've never tried using an epoxy and closing the hole and redrilling it to the stock specs, but it may be worth a try to see if it stops your problem, if so you could either replace it or use it as is. The reason I use this method over the replacement of the main jet needle as mentioned is because most people do not have the knowledge of the proper needle to use or how to tune the circuits in the carb properly, where to buy and other facts like dyno access to dial the carb in. This is after all the smoke clears the easiest way for most to tune the carb for more power and does work well. Will it get you an exact AFR? ...probably not, but it will run much better with a minimal outlay of $$$ and knowledge. I've set a lot of bikes up like this and they ran well.
As far as your question about the mixing of parts, I would advise not to mix parts, these recommended settings that I use all use the stock carb and parts and go from there. The MPG does not suffer with these mods as it does with the DJ kits and others and the bike runs well.
Hope this cleared it up for you...
The coughing is no doubt like I said due to the drilling of the slide and the weaker spring also. It causes the slide to raise too fast, and at a slower RPM, this is where the problem happens. You could try replacing the stock spring and it should help here. Only other suggestion is replace the slide. I've never tried using an epoxy and closing the hole and redrilling it to the stock specs, but it may be worth a try to see if it stops your problem, if so you could either replace it or use it as is. The reason I use this method over the replacement of the main jet needle as mentioned is because most people do not have the knowledge of the proper needle to use or how to tune the circuits in the carb properly, where to buy and other facts like dyno access to dial the carb in. This is after all the smoke clears the easiest way for most to tune the carb for more power and does work well. Will it get you an exact AFR? ...probably not, but it will run much better with a minimal outlay of $$$ and knowledge. I've set a lot of bikes up like this and they ran well.
As far as your question about the mixing of parts, I would advise not to mix parts, these recommended settings that I use all use the stock carb and parts and go from there. The MPG does not suffer with these mods as it does with the DJ kits and others and the bike runs well.
Hope this cleared it up for you...
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