Ideas on tunning
-
You can go one step further and fit the entire VForce4 Reed Block assembly.
https://dt125r.co.uk/topic/2914/vforce4-reed-block-upgrade-yamaha-dt125r-re-xZeeltronic and Exhaust made the biggest changes to me.
I never got on with the port tuning if I'm honest.
And the one thing I've grown to appreciate is the Athena Big Bore kit. It took a long time to appreciate it, but when you accept the DTR isn't an RS 125, then having the extra CCs and drop in overrev, actually suits the DTR nicely.
-
You can go one step further and fit the entire VForce4 Reed Block assembly.
https://dt125r.co.uk/topic/2914/vforce4-reed-block-upgrade-yamaha-dt125r-re-xZeeltronic and Exhaust made the biggest changes to me.
I never got on with the port tuning if I'm honest.
And the one thing I've grown to appreciate is the Athena Big Bore kit. It took a long time to appreciate it, but when you accept the DTR isn't an RS 125, then having the extra CCs and drop in overrev, actually suits the DTR nicely.
@Calum i was looking forward to the zeeltronic but it costs 450€ on ebay to germany i think its a bit too much and as for the athena kit i heard that you have to modify the cases a bit to fit it and i dont want to ruin the cases bc if the cylinder goes bad at some time then i cant reuse the old one, btw what carb were you running eith the vforce
-
I would re-machine the head first to a 'proper shape' and squish, possibly raising compresson a little. Depending on what shape the head has now, it can make a significant improvement.
Change the pipe and re-jet to suit the pipe and modified head.
You can also play with ignition timing with the stock CDI with offset keys, or possibly by filing the holes a bit to rotate the stator plate. Easy to get too much advance with the offset key I suspect, but I have seen dyno charts of it giving good results.The reed will probably not make any significant difference with a near stock setup, you could cut some reed petals from some 0.3mm carbon reed material (I use Polini). Leave the reed stops in in this case. 0.3mm should be ok for the revs you are likely to acheive, and should improve bottom end and throttle response a tiny bit. Going too thick will give you less midrange and throttle response and more pressure drop over the reed (bad -less power).
I do like the Zeeltronic, but you need to be a bit of a nerd to fiddle around to get the tuning right, and it should be done on a dyno. 'Butt-dyno' works pretty well once you learn, at least for power valve to pipe adaptation, but the fine tuning of the ignition is better done on a dyno to make it good AND safe. In the end you will be rewarded with better power (and wider/smoother power band) and better throttle response.
-
I would re-machine the head first to a 'proper shape' and squish, possibly raising compresson a little. Depending on what shape the head has now, it can make a significant improvement.
Change the pipe and re-jet to suit the pipe and modified head.
You can also play with ignition timing with the stock CDI with offset keys, or possibly by filing the holes a bit to rotate the stator plate. Easy to get too much advance with the offset key I suspect, but I have seen dyno charts of it giving good results.The reed will probably not make any significant difference with a near stock setup, you could cut some reed petals from some 0.3mm carbon reed material (I use Polini). Leave the reed stops in in this case. 0.3mm should be ok for the revs you are likely to acheive, and should improve bottom end and throttle response a tiny bit. Going too thick will give you less midrange and throttle response and more pressure drop over the reed (bad -less power).
I do like the Zeeltronic, but you need to be a bit of a nerd to fiddle around to get the tuning right, and it should be done on a dyno. 'Butt-dyno' works pretty well once you learn, at least for power valve to pipe adaptation, but the fine tuning of the ignition is better done on a dyno to make it good AND safe. In the end you will be rewarded with better power (and wider/smoother power band) and better throttle response.
@Rallyfinnen i have a 3bn head if im not wrong which is not restricted but one time i got it too hot and had to machine both the cylinder surface and cylinder head by .10mm .20-.30 mm in total so im runing a 1mm base gasket now as i didnt have time to check for squish, probably with open up on winter and check squish with solder wire and and change base gasket as needed to get the recomended squish to run on high octane fuel, btw i got a athena silencer on its way, im thinking of getting a athena pipe too as its easier for me to get a hold of as i know a guy who has a wrecked dt125r with a athena pipe as i could identify it. But what about the zeeltronic tho is there any way i can find it cheaper either for germany, switzerland , or kosovo somehow
-
You don't need to modify the cases to run the Athena 170 kit. Not sure where you've gotten that from.
The 3BN is the restricted head, 3MB is the non-restrictive head.
You don't really need to faff about with dialing in the Zeel as it comes with 5 maps that they've tuned. Of course to maximise the performance then yeah, you need to dial it in. But it was one of the single most performance increases I noticed.
-
Check ebay etc for used Zeeltronic maybe, but new that is about the price you have to pay.
Adding base gaskets will increase your port timings, maybe not a bad thing though, but an extra base gasket is a significant change on transfer duration.
You can weld and machine the 3BN head or get another one, but you will probably have to machine the other head too, to get a decent squish.
I have the Athena pipe, and it's better than the original (especially if the original is restricted), but also louder. -
You don't need to modify the cases to run the Athena 170 kit. Not sure where you've gotten that from.
The 3BN is the restricted head, 3MB is the non-restrictive head.
You don't really need to faff about with dialing in the Zeel as it comes with 5 maps that they've tuned. Of course to maximise the performance then yeah, you need to dial it in. But it was one of the single most performance increases I noticed.
@Calum im not really sure i will have to check but it didnt have the little step all around like a wall as i remembered the restricted one had i saw some photos as for the athena maybe it will come later on the way now im thinking of new crab v force reeds and the zeeltronic if i find it with a bit more reasonable price
-
@MadGyver what about the yz reed cage are you happy with it or should i just go with only the boyesen reeds
@eriondt125r
The YZ reed cage was used because it suited better my setup.
Dropped my max rpm, widened the power band. It's a more civilized bike now.An 170kit as is,with a tuned or aftermarket reed valve,an after market exhaust and a programmable CDI (zeeltronic or ignitech) will make a whole new bike and an 70-80% of the second route.
The other route is from ground up build and tune almost everything in the engine and not only.
A lot of reading, searching, calculations, note keeping, machining, adjusting, combining info/parts.
Will give you a bike like what you see from a specific Portugal tuner, but with more money, time and headaches spend in the end.......knowledge is a side-effect bonus.I will not recommend this torment to you , get the first choice.
-
@eriondt125r
The YZ reed cage was used because it suited better my setup.
Dropped my max rpm, widened the power band. It's a more civilized bike now.An 170kit as is,with a tuned or aftermarket reed valve,an after market exhaust and a programmable CDI (zeeltronic or ignitech) will make a whole new bike and an 70-80% of the second route.
The other route is from ground up build and tune almost everything in the engine and not only.
A lot of reading, searching, calculations, note keeping, machining, adjusting, combining info/parts.
Will give you a bike like what you see from a specific Portugal tuner, but with more money, time and headaches spend in the end.......knowledge is a side-effect bonus.I will not recommend this torment to you , get the first choice.
@MadGyver yeah as for now those are the things im considering as i use the bike for enduro too and im planing on later on to leave it only for road use and get it more snapier on throttle and power, rn just thinking of plans i got a idea of lightening the flywheel too for better rpms as it will lose a bit low end torque but for road use thats okay, so yeah a vforce4 a bigger carb maybe 30mm, zeeltronic setup and a bit setting up squish and cylinder height as i dont have a bigg budget things will he coming up slowly and would like for everyone who sees this to bring their ideas and i will hopefully keep you upt with the project
-
@eriondt125r
Leave the flywheel alone. The TM28 is ok, DT200R uses the same with different jetting,so it's up to the task. Adding a power jet is a bonus if doesn't have integrated.
Squish is ok and already needs minimum 96 octane as Athena mentions.I tempered with squish,height and combustion dome and now needs minimum 99+ from a good gas station, otherwise pinning heavily. Doesn't worth with gas prices.
I plan to lower the compression and dome shape so be able to run 91 octane gas. -
@eriondt125r
Leave the flywheel alone. The TM28 is ok, DT200R uses the same with different jetting,so it's up to the task. Adding a power jet is a bonus if doesn't have integrated.
Squish is ok and already needs minimum 96 octane as Athena mentions.I tempered with squish,height and combustion dome and now needs minimum 99+ from a good gas station, otherwise pinning heavily. Doesn't worth with gas prices.
I plan to lower the compression and dome shape so be able to run 91 octane gas.@MadGyver im talking about the stock 3mb-00 cylinder asn the stock cylinder head i want to modd them for higher octane fuel for ex like 0.9 0.8 if its possible or a bit higher than the lowest safe squish and as for the carb i will maybe switch to another with the extra jet and the reeds, btw are you running 170cc kit or stock and if so did you feel a diference at power when adding work on the head dome and squish
