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I will support the whole DIY porting, but opening the transfers should be done carefully and it should not be to big as well, the transfers are angled. On the stock jugs 2 are angled to the back of the cylinder and 2 to the center, this is important for performance and cooling reasons and some other reasons as well. By changing the angles can have a dramatic result on power at certain engine speeds (gains & losses). If you inspect your transfers, there is a incoming angle and a deflecting angle. If the transfers are to big, the mixture's entering speed is slower as it was, but you can open it up a little, the question is how much, that is where all the guys that have messed up cylinders over the years came up with the right sizes and the 2-stroke software really comes in advantage. I have to say the books of Gorr and A Graham Bell's 2-stroke performance tunning explane this very well. All the big name builders these days use software to help reshape the ports and this is a huge advantage.

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this will be on stock cylinders.. i was thinking i would only port halfway down into the transfers (from the base first) and not touche the roof of the port, i know that is where a lot of difference is made, i was just going to open up what is there for more volume, i noticed that there is aluminum casting that is touching the the sleeve on the inside of the transfers, can that be removed? i noticed it has a humped like shape, maybe it is part of what directs the mixture flowing through?? i have noticed that a lot of times (from pictures) the material is removed from the outside wall(opposite of the sleeve) in the transfers, like i sad just wanted to open them up from the base to about halfway through.. any suggestions?? and u guys that did this yourself what did u notice from it?? any difference?

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this will be on stock cylinders.. i was thinking i would only port halfway down into the transfers (from the base first) and not touche the roof of the port, i know that is where a lot of difference is made, i was just going to open up what is there for more volume, i noticed that there is aluminum casting that is touching the the sleeve on the inside of the transfers, can that be removed? i noticed it has a humped like shape, maybe it is part of what directs the mixture flowing through?? i have noticed that a lot of times (from pictures) the material is removed from the outside wall(opposite of the sleeve) in the transfers, like i sad just wanted to open them up from the base to about halfway through.. any suggestions?? and u guys that did this yourself what did u notice from it?? any difference?

 

 

As far as the casting flows, you can remove them, not sure which ones you are talking about. I did some aggressive porting on my RGV250, open the transfers at the deck side and the intake. I also case ported them so that the cases and jugs lined up smooth and make sure the gasket is cut to match precise as well, the RGV performed like I could not believe it and that was the 1st bike I've ported, no lies. But it is true, take your time and if you get tired, put it away and do it another day..

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yeah the stock transfers are pretty narrow.. was wanting to open up the narrow spot that is close to the base, that is what i am trying to describe i guess.. but i am not wanting to hurt my low end power. do u think it will just have more power everywhere?? i would also polish the hell out of the exhaust ports..

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yeah the stock transfers are pretty narrow.. was wanting to open up the narrow spot that is close to the base, that is what i am trying to describe i guess.. but i am not wanting to hurt my low end power. do u think it will just have more power everywhere?? i would also polish the hell out of the exhaust ports..

 

I am not so much of a porting guru to say where the gains have been, But that should not heard, OR THAT WAS MY EXPERIENCE from the RGV. It had a little lag in the midrange but bottem was good with a screaming top end. Do not polish the intakes...

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I am not so much of a porting guru to say where the gains have been, But that should not heard, OR THAT WAS MY EXPERIENCE from the RGV. It had a little lag in the midrange but bottem was good with a screaming top end. Do not polish the intakes...

Most of your power gain is in the exhaust ports (mid to top power) You can widen and raise them some (a couple of mm unless u want a drag bike) .The fine details in the intake, transfers and case bring back up the bottom end power and add a little more everywhere. The exhaust is the biggest deciding factor in how much power and where the power band is. Blend your transfers where the jug and sleeve meet on the bottom side and knife edge the bridges in them. You can also clean up the casting flaws where the transfers enter the cyl, but be carefull not to take too much out as this will hurt ur bottom end. The earlier pics are pretty good for the intake windows. Make sure both cylinders are identical (Measurement and shape) and be sure to chamfer the ports so you don't hang a ring.

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so do u think opening the transfers up some will hurt the bottom end power?? i am talkin about just opening them up at the base(where they bolt to the crankcase) and going about half way up, i am planning on leaving the roof angles alone.. what gains will be had doing this and also opening up the intake side and polishing the exhaust.. i will not do any cutting on the sleeves( port timings will be stock) and if the opening of the transfers is done how much bottom end will be lost if any, also what gains are gonna be had?

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snoop, that book is QUITE hard to buy brand new as it is out of publication. took me about months of bookstore trips before one of them tracked it down for me in hardcover to match my 4 stroke version.

but as for anything DIY i ALSO recomend reading this book cover to cover. british people know what their doing. i mean, just look at what they put their own vehicles through....

the banshee blue book of tuning is a damn fine resource and will teach you alot even if you think you already know it all. hell you can build your own pipes for any rpm range based on your engines measurements from the knowledge and formulas given inside.

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snoop, that book is QUITE hard to buy brand new as it is out of publication. took me about months of bookstore trips before one of them tracked it down for me in hardcover to match my 4 stroke version.

but as for anything DIY i ALSO recomend reading this book cover to cover. british people know what their doing. i mean, just look at what they put their own vehicles through....

the banshee blue book of tuning is a damn fine resource and will teach you alot even if you think you already know it all. hell you can build your own pipes for any rpm range based on your engines measurements from the knowledge and formulas given inside.

 

I ordered the book last monday off amazon, and had it by wednesday.

 

Remember, the book gives theory and starting points. Most of it is geared around road racing though.

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If you are thinking about doing any porting I would say to look into a real porting tool. Like a Fordom, CC Specialty, WeCheer, and some good Chinese knockoffs on ebay. The motor is 1/4 to 1/3 HP and is remote (sets on a stand,or lays on the table). They have way more control because they use a foot pedal,varieble speed. When you are cutting aluminum you don't want the cutting burr to create heat and melt the aluminum. When that happens it will be a harder spot and then hard to get leval. Been there and did it. With those machines you can go slower and see what is happening better than a Dremal that turn at 20,000 rpms.

Cleaning up the intake and the transfers won't hurt at all. Taking the exhaust port up and opening the transfers up, up meaning taking matieral off the top of the port, and changing the angle of the transfer ports as they come into the cylinder is where you can mess things up.

Somthing to think about. I remember this being said often on the old Banshee HQ

The Stock carbs will flow more air than the stock reed cages will flow, and the stock reed cages will flow more air than the stock transfers will flow. So think about that when asking "Will Vforce reeds help my stock motor?" Yes to a point, but if your cylinders are ported they will be way better. Then you might need some bigger carbs. Then all this you have done may be to much for those old pipes and you need some that work more at high revs. All of the component need to work together. Just putting CPI's on a Banshee won't do a lot,(prolly better than stock). But matching things will take you farther than radical changes on either end of the cylinder.

Sorry about the lecture :blink: . Yea go ahead and clean up the intake,ports and tranfers it will help.

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if you keep your eye on ebay , good deals come up on already ported cylinders with pistons from well known builders , i have more than 5 times bought and sold stock cylinders and bought ported cylinders and have never paid a penny for and portwork , plus cylinders with hacked up port work are worth way less than stock unported cylinders .

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If you are thinking about doing any porting I would say to look into a real porting tool. Like a Fordom, CC Specialty, WeCheer, and some good Chinese knockoffs on ebay. The motor is 1/4 to 1/3 HP and is remote (sets on a stand,or lays on the table). They have way more control because they use a foot pedal,varieble speed. When you are cutting aluminum you don't want the cutting burr to create heat and melt the aluminum. When that happens it will be a harder spot and then hard to get leval. Been there and did it. With those machines you can go slower and see what is happening better than a Dremal that turn at 20,000 rpms.

Cleaning up the intake and the transfers won't hurt at all. Taking the exhaust port up and opening the transfers up, up meaning taking matieral off the top of the port, and changing the angle of the transfer ports as they come into the cylinder is where you can mess things up.

Somthing to think about. I remember this being said often on the old Banshee HQ

The Stock carbs will flow more air than the stock reed cages will flow, and the stock reed cages will flow more air than the stock transfers will flow. So think about that when asking "Will Vforce reeds help my stock motor?" Yes to a point, but if your cylinders are ported they will be way better. Then you might need some bigger carbs. Then all this you have done may be to much for those old pipes and you need some that work more at high revs. All of the component need to work together. Just putting CPI's on a Banshee won't do a lot,(prolly better than stock). But matching things will take you farther than radical changes on either end of the cylinder.

Sorry about the lecture :blink: . Yea go ahead and clean up the intake,ports and tranfers it will help.

yea i have started porting.. i have smoothed up the tranfers, knife edged the birdges, and also opened the tranfers up a little to where u can tell but its not extensive, i also smoothed the intake and narrowed the bridge just a little(not the sleeve) and put a smotth contoured edge on the bridges also.. i definately do not want to lose lowend or mid by doing this so i hope its not a mistake, i am not going to change the port timings. i just want to add more power everywhere by letting the engine breath a little easier.. do u think i will lose any lowend power?? or just gain it everywhere like i am thinking, i have done a beautiful job so far, actually proud of myself so i will post some pics later..

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