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What are some engine mods 4 the 125

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What are some mods I can do that are cheap?iv heard about milling the head. How much differance does this make?and wat about port and polish?has any one tryed advancing the timing?How much differance do Hi comp. gasket kits make.any mod ideas would be sweet

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Probably Best bet is Pipe ,silencer , reeds,jet kit "if it needs it " Port and Polish Porting does just to make the air flow and gas flow better in other words not that great or notice any power diff. and polish doesnt add for performance its kinda for looks i think.

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Probably Best bet is Pipe ,silencer , reeds,jet kit "if it needs it " Port and Polish Porting does just to make the air flow and gas flow better in other words not that great or notice any power diff. and polish doesnt add for performance its kinda for looks i think.

Best bet to make more hp....is a well packaged motor.

That means the porting matches the pipe and the reeds and carb or spaced properly to match all that.

Porting has nothing to do with bulk "air flow" in a two stroke as compared to a four stroke.

Instead is has to do with harmonics...and flow within those harmonics. So you can get more power by optimizing all of that....most porting on two strokes makes the bike rev higher to make more hp...also making it more pipey.

in the honda's case...it's stock porting isnt' really great anywhere.

To make it match other brands in at least RPM's it often requires porting to just put it "on par"

So I feel a well ported cylinder with head mods to match THAT cylinder and fuel being used are best bang for buck. Heck the stock honda pipe is pretty darn good actually.

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If you want to make more power from your 125, the best thing to do is make it a 250. Throw all of the money you want at it and you might gain 1-2 horsepower at around 35 horsepower total. Step up to a 250 and you'll start around 45 horsepower.

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Save your money for parts your bike needs, tires, top ends, etc. and try to ride as much as possible. This will make you way faster than any motor mods.

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I don't want to go faster,I mostly want low end power with out gearing it.

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If your not using all the gears now....and not tapped out..then gear it down.

Cheaper than mods, and effective.

a 125 was never a bike that produced good low end.

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get a 1 to 2 tooth larger rear sprocket. vertex piston makes a slight higher compression piston you can buy without any mods to your head or cylinder, you can reverse these mods. that will give some low end part number to the vertex is 22190a it is not a huge gain but it's better than nothing, I have been using this piston in 90-03 cr 125's so far.

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Try Eric gorr port job. Good value for money. Tell him where you want your power, he'll be able to sort it out. He'll offer some other suggestions to help. I had a 1994 KX125 that had brilliant midrange that peaked about 9000rpm. The previous year peaked at 12000rpm. the 94 was much easier to ride. I have also had my current motor ported & it made a great difference for me.

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Gorr does a great job. I had him build a 144 cr for me. its a blast and for around 500 i think it was worth it.

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Wat about milling the head?

you can do that too but a piston with high comp gives you a choice to go back, milling the head you can do it too but will have to run 2 gaskets, even then it's hard to determine where you really are, why don't you just get a rear sprocket?

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I don't what to loose any more speed,but I guess I could try it.I got a 53 on it now...

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Just push the head back and forth across 60grit sandpaper on a flat surface. Real easy and its free. Just takes a bit of time. Also you can port the exhaust port, widen the transfers, enlarge the boost port, add a reed block spacer to move the reed block back so you can take advantage of the enlarged boost port. Then port match everything, rejet the carb, FMF pipe, upgraded reed block, boost bottle and you are making some good gains.

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Save your money for parts your bike needs, tires, top ends, etc. and try to ride as much as possible. This will make you way faster than any motor mods.

Words to live by :thumbsup::usa:

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V-force reeds, Fatty pipe, Shorty silencer, Twin Air filter, and go up 2 teeth on the back sprocket...

Keep the top end fresh and you should be pretty good... make sure your jetted right!

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It really depends what kind of riding one does. Me personally, I got tired of eating big rocks everytime a 450R passed me on my 06 CR125 on the straights. It doesn't matter how good you are, if you are not making power, you are eating dust long straight sections. Going lower in the gearing only helps if you are riding in a place where you are not pinned wide open all the time. You can be the best rider in the world and still have 3 pound rocks bouncing off you helmet from the roost of a larger bike if you don't have the power to accelerate and more top end charge like the larger bikes.

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