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Discussion Starter #1
Hey everyone longtime no post. I been slowly working one the old TS and it coming along ok. It might not be the classic style cafe bike but that project is saved for a better starter bike. Anyway can anyone tell me the basics of porting 2-stroke engines. Where should I search, what should I know? Second is it possable to convert a 6 volt system to a 12 volt? Thanks for your help.
 

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"porting" is a very loosely used term. altering the factory port openings is a process which should be proceeded by determining your goals/intentions with the bike/engine. if you intend to continue riding it on the street, it is doubtful any improvement can be had. if you want to increase peak power, it WILL come at the expense of tracibility/usablilty. the modifications to port timing and volume must be part of broader intake and exhaust calculations. numerous software programs are available to work through these mod.s but don't expect it to be easy. at best you'll end up with a faster (and louder)bike with which you don't mind the short comings too much (poor idling, flat spots, poor lower-end torque). at worst, your bike won't be any faster and will run like shit too.
-parks
 

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if your intake and chambers are stock, then leave the ports stock. Ports, carbs, and chambers are all best changed at the same time and should be maximized to work with each other. If you look at other high performance 2 strokes that had hi-po "packages" available in the 1970s, they will always have a matching pipe available for the porting specs (like denco for the h series bikes).

A lot of the older two strokes run really low compression (like 8:1). Sometimes you can get a better performance bump out of decking the head than you can with porting the motor.
 

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Discussion Starter #6
I understand that porting 2-stroke is a science, thats why I asked. So what is decking a head? Well maybe I would be better to put it this way. What would I have to do to get better performance out of an old 2 stroke motor. I am a machinist so don't skimp on the details. Thanks for your help so far.
 

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First thing would be to freshen the motor. Rings and head gasket. Check the seals and make sure there are no leaks.

Decking is taking a small amount ( a few thousandths or less) off the mating surfaces of the head and barrel, thereby increasing compression.

I would not do any porting unless you have the specific porting manual for the engine you have, or you have multiple sets of barrels, or you are REALLY good friends with FrankC or Keith Cameron. Some older bikes had additional tech bulletins that included porting info, as they knew hot rodders would want the info the factory had. My 1966 YL1 100cc came with porting info, along with carb and piston mods. Really cool.
 

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one way to play with the effects of porting without doing any permanent changes to the cylinder is to machine yourself a set of cylinder spacers. moving the cylinder up changes the port timing. when you change the height of the port it opens sooner - similar effect to advancing the cam timing in a 4 stroke engine. this allows your valves to open sooner but you don't loose any of the backpressure that is needed (REALLY NEEDED) to make horsepower in the engine.

More than likely your TS is a piston port two stroke (uses the underside of the piston to draw in and move air/fuel). The best mod you can do is to make (or adapt) a reed valve. A reed valve is basically a one way door in the intake that allows an incoming charge but won't let it go back into the carb. you will get much more precise air fuel metering and probably pick up a lot more response.
 

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it is possible but you will have to rewire the entire bike. Even the light bulbs will need to be changed. I didn't know suzuki still made 6volt bikes in 1974....

I wonder if thr ts uses the same motor as the gt250? I think those are 12volt.

you should probably check with the guys over at the suzuki two stroke message board:

http://vancouver.globat.com/~sundialmotosport.com/phpBB2/

off the top of my head the tc models were 12 volt and used the same engine (tranny's are different), but good luck finding a tc250, they are kind of rare.
 

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it is possible but you will have to rewire the entire bike. Even the light bulbs will need to be changed. I didn't know suzuki still made 6volt bikes in 1974....

I wonder if thr ts uses the same motor as the gt250? I think those are 12volt.

you should probably check with the guys over at the suzuki two stroke message board:

http://vancouver.globat.com/~sundialmotosport.com/phpBB2/

off the top of my head the tc models were 12 volt and used the same engine (tranny's are different), but good luck finding a tc250, they are kind of rare.
 

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Discussion Starter #13
I guess my main question or that would be if the CCI could handle it or would I have to figure something else out? Those bike were rats nests from the factory so rewiring woudn't be bad.
 

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Discussion Starter #14
I guess my main question or that would be if the CCI could handle it or would I have to figure something else out? Those bike were rats nests from the factory so rewiring woudn't be bad.
 

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I think you will need the cci off of the tc 250 (maybe the TC185 is the same - they are 12v and a heck of a lot more common). your best bet is to check the parts fiche...if the part numbers are the same between the two models then you are golden, if not....well start looking for alternatives.
 

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I think you will need the cci off of the tc 250 (maybe the TC185 is the same - they are 12v and a heck of a lot more common). your best bet is to check the parts fiche...if the part numbers are the same between the two models then you are golden, if not....well start looking for alternatives.
 

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Discussion Starter #17
As far as spacers for the cyclender goes about how much should I lift it? And how much does one shave the head for a better compression?
 

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Discussion Starter #18
As far as spacers for the cyclender goes about how much should I lift it? And how much does one shave the head for a better compression?
 

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quote:Originally posted by oldTS

As far as spacers for the cyclender goes about how much should I lift it? And how much does one shave the head for a better compression?
that is all up to expirementation....a good place to start would be to talk to some of the suzuki guys and see if someone has some race porting specs out there and see how much they advise lifting the port.

honestly, make a reed valve for it and leave the rest stock, anytime you play with changing the intake/exhaust timing you can cut down the reliability.

As for shaving the head? I have a set of shaved t500 heads and I can take a measurement but it usually isn't much more than a couple of thousandths. The best way to figure it out is to find your base compression ratio and then do the math as to what a decreased combustion chamber volume will net you. you only want to bump it a point or so, and if it is already 9:1 you might just want to leave it alone. my T500 was something like 8:1 stock and the shaved heads I have bump it to 9:1 (the previous owner of the bike did the head work so I don't know how many thousandths have been removed).
 

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quote:Originally posted by oldTS

As far as spacers for the cyclender goes about how much should I lift it? And how much does one shave the head for a better compression?
that is all up to expirementation....a good place to start would be to talk to some of the suzuki guys and see if someone has some race porting specs out there and see how much they advise lifting the port.

honestly, make a reed valve for it and leave the rest stock, anytime you play with changing the intake/exhaust timing you can cut down the reliability.

As for shaving the head? I have a set of shaved t500 heads and I can take a measurement but it usually isn't much more than a couple of thousandths. The best way to figure it out is to find your base compression ratio and then do the math as to what a decreased combustion chamber volume will net you. you only want to bump it a point or so, and if it is already 9:1 you might just want to leave it alone. my T500 was something like 8:1 stock and the shaved heads I have bump it to 9:1 (the previous owner of the bike did the head work so I don't know how many thousandths have been removed).
 
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