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what to do to pull more power out of my 125

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Ok, I have a 1997 RM125, the bike runs great and pulls with PLENTY of power, my jug has been freshly replated by millineum technologies, and it has a new top end in it. A r304 shorty and a stock expansion chamber, 50T rear sprocket and stock tooth front sprocket. My question is what can i do to pull more umph out of it. I've been looking at vforce 3 reeds, aftermarket expansion chambers like works gold series, platinum series, etc etc. but will these really help me that much? and i race tight indoor tracks and some outdoor tracks. i know my rear sprocket is too small im going to either a 52 or a 54 tooth in the back and im not sure about the front. But i know the V Force 3 reed setups are expensive, but are they really worth it? Thanks for the input guys.

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V Force reed cages are very good and lot's of guys like them ~ same thing for the Boyesen RAD Valve reed cage. Although I personally would try a set of Boyesen Pro Series reeds way before either one. The Pro Series reeds normally do not require any jetting changes but both the V Force and the RAD Valve will require jetting changes, and the Pro Series reeds will still be a noticable change.

A pipe would also help, either a PC or FMF would be an improvement over stock. And with your r304 silencer I'd go with a PC Platinum pipe. Finally try jumping the rear sprocket up two teeth first. That's a big jump and it should be very noticable even with all of the other changes.

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Ok i'll look into the pro reeds and im also going to get a 52 or 53T rear sprocket and platinum pipe

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If you decide on the 53 then save yourself a lot of money and just get a front sprocket with one less tooth instead. Same thing and doesn't mess with chain length near as much.

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If you decide on the 53 then save yourself a lot of money and just get a front sprocket with one less tooth instead. Same thing and doesn't mess with chain length near as much.

Good point, where can i find an 11 tooth front sprocket?

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Good point, where can i find an 11 tooth front sprocket?

LOL, even a better point! No idea. Sorry man, I've been in quad mode lately. Land of 14 and 15t stock fronts.

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Dont go for the 11 tooth. That tiny front sprocket will wear your chain out fast, you'd be better off getting the 53 rear.

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How much should i mill the head? and how much will it raise my compression numbers? Im worried about grenading the top end with the head being milled.

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I usually set the squish on 125s at 0.8 mm. To clarify, squish is the measurement between the head and piston. If you need more info on milling the head or porting, just shoot me a PM.

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Ok, I have a 1997 RM125, the bike runs great and pulls with PLENTY of power, my jug has been freshly replated by millineum technologies, and it has a new top end in it. A r304 shorty and a stock expansion chamber, 50T rear sprocket and stock tooth front sprocket. My question is what can i do to pull more umph out of it. I've been looking at vforce 3 reeds, aftermarket expansion chambers like works gold series, platinum series, etc etc. but will these really help me that much? and i race tight indoor tracks and some outdoor tracks. i know my rear sprocket is too small im going to either a 52 or a 54 tooth in the back and im not sure about the front. But i know the V Force 3 reed setups are expensive, but are they really worth it? Thanks for the input guys.

For what your looking for out of the same bike on two tottaly different types of race tracks, tight indoor tracks and outdoor tracks, you need at least two different set ups, and you need more options to build on those two setups. On tight tracks, you need low and mid grunt to pull out of the corners and power to clear the jumps. You don't need a power house top end bike to run 25 to 30 foot straight aways. However, now take that same bike set up for indoors and put it on a outdoor track and you will be in the back of the pack. Now you need that mid and top end power to pull down the longer 100 yard straights, more sloped jumps with longer gaps.

Gearing is #1 on the list for both types of tracks.

And no one said anything about suspension. That should rate #2 if not #1. Very important for both types of tracks. Face it, if the bike does not handle, then no matter what kind of power you have the bike just will not work for you.

The right power for the track is #3.

Now if you want to use the same bike on both tracks, then you need to compromise. Gearing, suspension changes (springs at least, and oil weight), pipe and silencer, and the all very important jetting changes.

You want to take it a step more, then you really need a cylinder and head ported and milled for low and mid for indoors and a cylinder and head ported and milled for mid and top end power for outdoors.

There are hundreds of ways to make handling changes to improve any parts changes, such as using a short chain in indoors to shorten the wheel base of the bike and use a longer chain for outdoors. I know I just did not spit out specific parts for you, but my goal was to make you think and study what would be the best parts to accomplish what you expect out of your bike and you as a rider. Good luck.

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For what your looking for out of the same bike on two tottaly different types of race tracks, tight indoor tracks and outdoor tracks, you need at least two different set ups, and you need more options to build on those two setups. On tight tracks, you need low and mid grunt to pull out of the corners and power to clear the jumps. You don't need a power house top end bike to run 25 to 30 foot straight aways. However, now take that same bike set up for indoors and put it on a outdoor track and you will be in the back of the pack. Now you need that mid and top end power to pull down the longer 100 yard straights, more sloped jumps with longer gaps.

Gearing is #1 on the list for both types of tracks.

And no one said anything about suspension. That should rate #2 if not #1. Very important for both types of tracks. Face it, if the bike does not handle, then no matter what kind of power you have the bike just will not work for you.

The right power for the track is #3.

Now if you want to use the same bike on both tracks, then you need to compromise. Gearing, suspension changes (springs at least, and oil weight), pipe and silencer, and the all very important jetting changes.

You want to take it a step more, then you really need a cylinder and head ported and milled for low and mid for indoors and a cylinder and head ported and milled for mid and top end power for outdoors.

There are hundreds of ways to make handling changes to improve any parts changes, such as using a short chain in indoors to shorten the wheel base of the bike and use a longer chain for outdoors. I know I just did not spit out specific parts for you, but my goal was to make you think and study what would be the best parts to accomplish what you expect out of your bike and you as a rider. Good luck.

Dually noted and i appreciate you taking the time to explain, well I run indoors when it's too nasty to race outdoors and here recently (i live in kentucky) it's been very VERY wet and they've been canceling races in my season left and right. so i run the indoor track that's closest to me just so i can keep a feel for the track and dont get lazy. Where would i go to have my head ported and milled? Im almost certain that the machine shop closest to me has NO EARTHLY idea about porting the head for my 125. And what about down time? I have heard alot about eric gorr (i do almost all the work to my bikes myself) where can i find him? And how much is the average price for having the head milled? Sorry if it seems like im asking alot i just want to know everything from someone who's been there done that before i try to do something new to me without consulting someone with more knowledge first. Thanks.

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the best thing you can do is get a cheap pair of boyesen power reeds,dont bother with the cage setup and get eric gorr to port & polish job for all over the power range,and get a fmf fatty or pro cuircit plattnim pipe.Thats what i think for power wise,but suspention is really important aswell.

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I'll def look into it. i think im going to get my head milled and get my cylinder ported for top end, because i keep my bike WIDE OPEN at all time when im on the track and clutch it at all times, order a set of boyesen power or pro reeds, and a platinum pipe with a 52T rear sprocket and see how it runs then.

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