CV slide modifications....
Thread Starter
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Outstanding HDF Member
Joined: May 2007
Posts: 2,154
Likes: 5
From: Phoenix, AZ
CV slide modifications....
I have a new project I'm going to take on in the coming week, I'm gonna keep this thread going with results.
I've noticed a vast improvement with the Big Sucker that I was missing with just a K&N upgrade, but I still want a bit more throttle response and no amount of tuning has made me happy so far.
I'm pulling my carb apart next week and making some minor modifications to it. I'm rejetting again to compensate for my new baffles and a/c. Not sure if I'll have to change out one or both yet. I'm also rounding the 90* angles on the inlet side to allow more velocity over the surface and scotch briting the guides in the body to clean the gunk and any imperfections out and enable it to move much faster.
The desired end-result of course is a faster-moving slide and higher air flow with minimal restriction, which should yeild faster throttle response and a boost in performance after re-tuning.
I'm gonna take pics along the way and once I'm done I'll post the step by step with them. From what I hear this is a great way to see a major improvement with the CVs, so I figured it may help you guys out as well.
I'm picking up the jet kit and some other parts tomorrow night, and I'll probably spend all of wednesday or thursday working on this. Results should be up by the end of the week for sure though.
I've noticed a vast improvement with the Big Sucker that I was missing with just a K&N upgrade, but I still want a bit more throttle response and no amount of tuning has made me happy so far.
I'm pulling my carb apart next week and making some minor modifications to it. I'm rejetting again to compensate for my new baffles and a/c. Not sure if I'll have to change out one or both yet. I'm also rounding the 90* angles on the inlet side to allow more velocity over the surface and scotch briting the guides in the body to clean the gunk and any imperfections out and enable it to move much faster.
The desired end-result of course is a faster-moving slide and higher air flow with minimal restriction, which should yeild faster throttle response and a boost in performance after re-tuning.
I'm gonna take pics along the way and once I'm done I'll post the step by step with them. From what I hear this is a great way to see a major improvement with the CVs, so I figured it may help you guys out as well.
I'm picking up the jet kit and some other parts tomorrow night, and I'll probably spend all of wednesday or thursday working on this. Results should be up by the end of the week for sure though.
Road Captain
Joined: Jul 2007
Posts: 657
Likes: 4
From: Daytona Beach
RE: CV slide modifications....
CV carbs are good carbs and the thunderslide is great upgrade but what I've found is you can only get so much out of a 40mm CV.I'm not sure what kind of cams you're running or what kind of motor work you've had done but a carb upgrade may be the way to go if you want that crisp instant throttle snap.Mikuni HSR42 are a dime a dozen these days and can be had pretty cheap.Of course there are other choices but these Miks are easy to find ,install, and tune.
Road Master
Joined: Dec 2007
Posts: 763
Likes: 1
From: Middletown, MD USA
RE: CV slide modifications....
Definitely get a thunderslide kit. As for the CV, I switched to the Mikuni 42 and my bike put out more HP and torque with the CV. I may be going back to my CV.
Thread Starter
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Outstanding HDF Member
Joined: May 2007
Posts: 2,154
Likes: 5
From: Phoenix, AZ
RE: CV slide modifications....
Waiting on the carb upgrade until I get my heads, cams, and jugs done. But that's a bit off, so I'm gonna squeeze every last drop outta the CV without dumping too much into it for now.
Thought about the Thunderslide...I may go that route if I still don't get what I'm lookin for outta this.
Thought about the Thunderslide...I may go that route if I still don't get what I'm lookin for outta this.
Road Warrior
Joined: Jan 2007
Posts: 1,319
Likes: 2
From:
RE: CV slide modifications....
ORIGINAL: Terp84Alum
Definitely get a thunderslide kit. As for the CV, I switched to the Mikuni 42 and my bike put out more HP and torque with the CV. I may be going back to my CV.
Definitely get a thunderslide kit. As for the CV, I switched to the Mikuni 42 and my bike put out more HP and torque with the CV. I may be going back to my CV.
Road Master
Joined: Dec 2007
Posts: 763
Likes: 1
From: Middletown, MD USA
RE: CV slide modifications....
Thanks. I had it dyno tuned. The A/F was erratic over the RPM range.
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Outstanding HDF Member
Joined: Jul 2007
Posts: 2,192
Likes: 2
From: Metro Milwaukee, WI
RE: CV slide modifications....
I went with the Yost CV-40 Master kit. After installing the blue needle, on the 3rd notch, 45 Pilot 185 main,drilling the vacuum port on the slide to 1/8", and using the Yost spring, and the Yost emulsion tube, my throttle response is freakishly quick.
The power is smooth all the way through the power band and I havehad nothing that resembles a carb fart (once it's at normal operating temperature) since those mods even 32 degree weather.
The biggest reason I went with the Yost kit wasthefor the versatility. I have a slew of jets from 170 to 195 to choose fromnow as well as another needlethat I can use when the buell heads and pistons come into the mix.
The CV-40 will support up to 100HP applicationssufficiantly.
6o66er,if you areplanning to switch to a Mikuniin the future why would you spend $150 on the CV-40for a thunderslide when you can get the Yost kit for $89with free shippingfrom American Classic Motors? http://cgi.ebay.com/ebaymotors/CV-40...spagenameZWD1V
The Yost kit comes with Free tech support as well.
The power is smooth all the way through the power band and I havehad nothing that resembles a carb fart (once it's at normal operating temperature) since those mods even 32 degree weather.
The biggest reason I went with the Yost kit wasthefor the versatility. I have a slew of jets from 170 to 195 to choose fromnow as well as another needlethat I can use when the buell heads and pistons come into the mix.
The CV-40 will support up to 100HP applicationssufficiantly.
6o66er,if you areplanning to switch to a Mikuniin the future why would you spend $150 on the CV-40for a thunderslide when you can get the Yost kit for $89with free shippingfrom American Classic Motors? http://cgi.ebay.com/ebaymotors/CV-40...spagenameZWD1V
The Yost kit comes with Free tech support as well.
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Road Captain
Joined: Jul 2007
Posts: 657
Likes: 4
From: Daytona Beach
RE: CV slide modifications....
ORIGINAL: Biker Trash
I went with the Yost CV-40 Master kit. After installing the blue needle, on the 3rd notch, 45 Pilot 185 main,drilling the vacuum port on the slide to 1/8", and using the Yost spring, and the Yost emulsion tube, my throttle response is freakishly quick.
The power is smooth all the way through the power band and I havehad nothing that resembles a carb fart (once it's at normal operating temperature) since those mods even 32 degree weather.
The biggest reason I went with the Yost kit wasthefor the versatility. I have a slew of jets from 170 to 195 to choose fromnow as well as another needlethat I can use when the buell heads and pistons come into the mix.
The CV-40 will support up to 100HP applicationssufficiantly.
6o66er,if you areplanning to switch to a Mikuniin the future why would you spend $150 on the CV-40for a thunderslide when you can get the Yost kit for $89with free shippingfrom American Classic Motors? http://cgi.ebay.com/ebaymotors/CV-40...spagenameZWD1V
The Yost kit comes with Free tech support as well.
I went with the Yost CV-40 Master kit. After installing the blue needle, on the 3rd notch, 45 Pilot 185 main,drilling the vacuum port on the slide to 1/8", and using the Yost spring, and the Yost emulsion tube, my throttle response is freakishly quick.
The power is smooth all the way through the power band and I havehad nothing that resembles a carb fart (once it's at normal operating temperature) since those mods even 32 degree weather.
The biggest reason I went with the Yost kit wasthefor the versatility. I have a slew of jets from 170 to 195 to choose fromnow as well as another needlethat I can use when the buell heads and pistons come into the mix.
The CV-40 will support up to 100HP applicationssufficiantly.
6o66er,if you areplanning to switch to a Mikuniin the future why would you spend $150 on the CV-40for a thunderslide when you can get the Yost kit for $89with free shippingfrom American Classic Motors? http://cgi.ebay.com/ebaymotors/CV-40...spagenameZWD1V
The Yost kit comes with Free tech support as well.
Grand HDF Member
Joined: Sep 2007
Posts: 4,112
Likes: 40
From: Boise Idaho
RE: CV slide modifications....
You don't need any of those after market wonder kits, none of them do anything except part you from your money.
I have used Thunderslids andYost and they are a joke, I can add to that if you have any engine work done by a big shop like Zippers or Head Quarters the first thing they want to know is do you have one of thosewonder kits in the carb and if you do get it back out.
All you need is a couple of jets and a needle and you can polish up the slid just like you said.
Save your money you are on the right track!!!
I have used Thunderslids andYost and they are a joke, I can add to that if you have any engine work done by a big shop like Zippers or Head Quarters the first thing they want to know is do you have one of thosewonder kits in the carb and if you do get it back out.
All you need is a couple of jets and a needle and you can polish up the slid just like you said.
Save your money you are on the right track!!!