Better option?

Frodad78
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Frodad78
Bike: 2005 YZ125, Rad valve, PC pipe, stock silencer. I've tossed around a few other aftermarket parts and I'm left with a low to very strong mid power. Not much on top which is where I want to be, the bike lights up and hits hard put it just doesn't pull on top like I want it too. I think my speed is getting better, shit I'm blowing through some corners in 3rd. Stock gearing.

so do I,

Go with the DEP Rev pipe or

Send the head to EG and go for the mid top port job with the pump gas head mod.

I want the thing to scream around the track and rev to the moon, I don't need low end.

I'm thinking the Motor work is the better option. Looking for some opinions.

I've never had a ported bike and I think its exactly what I'm looking for. Plus the work from EG would be under 200 bucks.
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xnationalwrench 10/17/2016 1:27pm
10/17/2016 1:27pm
Try adding a tooth on the rear sprocket. Maybe some better reeds? Keep the throttle WFO would help also.
MxRyder
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MxRyder 10/17/2016 5:56pm
10/17/2016 5:56pm
Adding a tooth will not increase top end.....dropping a tooth can make the gears alittle longer.....now....porting the cylinder and modding the head are the only options for achieving your goals with this engine...EricGorr is the man...ive had 2 of his 295cc Mx race gas builds...and they were very reliable...no issues at all....that being said, their are some negitive experiances from a small group of others who werent as fortunate as my past and current engines....RB....2stroke performance...TDC...Forward Motion.....ESR.....and some other major 2stroke builders with good reps are on TT and Vital....look up yz295...Rm295...these same guys who build these monsters...also build some badass 125 motors......do some reading and pick who you think will be the best on what all the reviews you can read about say...it can help with shaping a valid choice.......i am with EricGorr 110%...until i experience a issue, and even then i give someone the benifit of the doubt to correct a error if one should arise..........
crc245
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crc245 10/17/2016 6:22pm
10/17/2016 6:22pm Edited Date/Time 10/17/2016 6:23pm
Why leave it with pump gas on the porting/head mod? Those YZingers like leaded 110 split with 91, and it's cheap insurance...Also, I've heard the Rad Valves bump low to mid whereas the Moto Tassarini VForces are more mid/top. Another thing to consider is the OE silencer; I run a shorty old Bills (non AMA compliant end cap style) and it breathes (and sounds) much better than stock.

Finally, since yours is an 05', have you done the shift stopper mod? I lost a complete set of cases and transmission gears on my 06'...The new (now superseded) part is a solid wheel whereas ours were a bearing style stock. Enjoy the bike and please keep us updated!

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Frodad78
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Frodad78 10/18/2016 5:19am
10/18/2016 5:19am
Thanks for the updates guys.

I've played with gearing and I don't like the extra tooth on the rear, the motor pulls the stock gearing incredibly well. If I didn't just slap a Renthal twinring on er I'd probably drop a tooth.

Yes I had a Vforce on there, while it did rev more, it didn't make any more power if that makes any sense. It revved to the moon and didn't go anywhere, it just stopped pulling.

I had the shorty on there as well with the stock and PC pipe. It just sucked all the over rev away and I was short shifting like a mofo.

I don't know much about race fuel, but I'll definitely look into it. With the addition of the rad valve it really made the power a little smoother and usable, very responsive. Its making great power, just now where I want the power to be!

I haven't done the shift stop mod, do you have to split the case to do the job?

Thanks for the information guys!!! I'm drooling over the idea of a ported 125, Basically building the bike I wanted when I was a teenager haha.
colintrax
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colintrax 10/18/2016 6:17pm
10/18/2016 6:17pm
Get the longest silencer made, and port it.
I had the same problem with my KTM 150. I was happy with the power, just didn't like how quickly it dropped off. Spent a few hours cleaning up the cylinder and matching the power valve to the exhaust flange. No real change, just revs a little further.

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