DT125R ARCHIVE

miguelNS · DTR Respected Member

RE: Athena 170cc kit, Help??

NorDt · Guru

I have removed the "Pig nose " on top of the air filtre box, And when i got the 170 kit i cut the hole bigger, Didnt work, had to open up the box on the right side. Im gonna try with the 28mm carb, and test it out, hopefully before new year, or right afterwards.

NorDt · Guru

Theres no such thing as a stock athena cyllinder miguel, Theres a Replacement for the stock wich is 125cc,

What i have is a athena big bore 170cc cyllinder. It has much more power than the stock cyllinder, But i cant get it up to the high rpms, and therefore i have a low top speed.

NorDt · Guru

Im thinking maybe the 170cc isnt as rpm willing as the 125cc and cant do as much rpm as the stock 125cc, But if i just get it to run clean, I could change the sprockets and it could still be faster than the stock.

NorDt · Guru

What about carbon reeds, how much difference does they make ?

miguelNS · DTR Respected Member

NorDt wrote:
Theres no such thing as a stock athena cyllinder miguel, Theres a Replacement for the stock wich is 125cc,

What i have is a athena big bore 170cc cyllinder. It has much more power than the stock cyllinder, But i cant get it up to the high rpms, and therefore i have a low top speed.

I know my english isnt perfect but your not reading.. And i'm not as dumb as you think i am. Try to figure my point :

1st i know dtr is 125cc stock, and i didn't said that it wasn't..

2nd There are stock athena cylinders because when you buy athena kit the cylinder comes stock, but 170cc stock do you get me?

You get the kit, you put it together on your bike and the bike will not be so much faster.. You'll have to tune up the 170cc cylinder. Tunning like messing up with transfers, admission, exhaust understand?

I advice you to read a 2-stroke tunning book or something and then try to understand what i am saying. ANd mate i'm not calling you dumb but i nottest that in this forum are few bikes that are tunned up.. And mate im not calling you dumb im just trying to transmit some new knowledges that we use in portugal..

Energized · DTR Legend

yeah mig :) i've ehard nothing but bad things about the athena kits, if i'd get a bigbore i'd go for the german one that the only way is yamaha linked for sure!

miguelNS · DTR Respected Member

Energized wrote:
yeah mig :) i've ehard nothing but bad things about the athena kits, if i'd get a bigbore i'd go for the german one that the only way is yamaha linked for sure!

But mate, a regular athena has potencial, but the setup of cylinder that comes out of athena factory is not being properly used.. You have to mess up with the setup a bit to make it powerful, very powerful after worked..

NorDt · Guru

Im gonna see if i can get it to run cleanly, And if it still doesent do any more than 120 kmh, / 65-70 mph, Im gonna change the sprockets, Cuz its no question about its power. Its strong as f****

the only way is YAMAHA DTR · Guru

have you bored out the inlet manifold to 34mm? you need to modify the reeds since you have a bigger carb , the reeds won't let anymore fuel in .unless you modify them

NorDt · Guru

The inlet manifold is stock, but had to make it a bit bigger to make room for the 34mm carb,

Also have stock reeds, Do they have to be changed ?

the only way is YAMAHA DTR · Guru

did you make it 34mm all the way through the manifold? the reeds wont help if they are standard

NorDt · Guru

No i didnt i just made it fit the carb, do you know any manifold that would be better than the standard one ?

the only way is YAMAHA DTR · Guru

you need to make the manifold atleast 34mm all the way through it or i will restrict the bike

miguelNS · DTR Respected Member

Mate just get this : Just fitting a 170cc kit will not make ur bike faster, period. It's not the reeds, but you can put some carbon ones btw but that will only help to inject more gas into the combustion chamber.. You have to open the transfers of the cilinder.. it's a hard thing to do, only a person who knows can do that. I'll have to post some vids to you people see what is a real 170cc compared to yours..

http://www.youtube.com/watch?v=K_15m94tsFg

see the first bike thats a dtr 170...

for you to see the power of that bike: here is against a Suziki RM 250 2 stoke that produces about 52hp

http://www.youtube.com/watch?v=mbdvvqFbpFs&feature=related

:))

NorDt · Guru

How will it restrict it ?, Could that be the cause of the bike only doing 120 km/h ?, Or is that just the cyllinder that doesent do any higher rpm ?.

I heard another guy in norway having a 28mm carb and dep, And hes bike doesent do any more than 120 km/h either.

But Miquel, Do you mean that i cant get my bike to do the same speed as it did stock with the 125cc cyllinder, Now that i have the 170cc kit ?.

And miquel, If i dont make the exhaust valves bigger, cause that is what your saying i have to do right ?, How fast can i make my bike go ?, If i just Fit the 170cc kit on the bike, with a gianelli exhaust ?

miguelNS · DTR Respected Member

NorDt wrote:
How will it restrict it ?, Could that be the cause of the bike only doing 120 km/h ?, Or is that just the cyllinder that doesent do any higher rpm ?.

I heard another guy in norway having a 28mm carb and dep, And hes bike doesent do any more than 120 km/h either.

But Miquel, Do you mean that i cant get my bike to do the same speed as it did stock with the 125cc cyllinder, Now that i have the 170cc kit ?.

And miquel, If i dont make the exhaust valves bigger, cause that is what your saying i have to do right ?, How fast can i make my bike go ?, If i just Fit the 170cc kit on the bike, with a gianelli exhaust ?

Dude your bike with a 170cc fitted can do more that 120km/h.. that dtr on the film is doing about 165-170km/h... But has lot of things changed and its a good preparation, you have to prepare the cylinder... boost it up.. change some measures in the combustion chamber.. maybe change the crankshaft and connecting rod to some high rpm ones.. thats a lot to be done and i can't do it neither can you...

the only way is YAMAHA DTR · Guru

theres no point having a 34mm carb , if the manifold is still standard bore, use a flap wheel or dremel to make the manifolds bore at least the same as the carbs bore (34MM)

NorDt · Guru

Miquel, How fast can i make my dt go without any changes on the cyllinder ??. im not gonna do any changes on it.

And Yamaha dtr how wil it restrict my bike ?.

NorDt · Guru

If i get a 34mm manifold, How wil it change my bikes power and top speed ?

the only way is YAMAHA DTR · Guru

it restricts your 34mm carb. because the carb is bigger, the manifolds internal diameter needs to be bigger e.g. 34mm

because the air and fuel mixture is in the carb and flows through the standard 28mm manifold, = less air can get through,

NorDt · Guru

Yes but i mean how does it affect the power of my bike ?, How would i notice it ?

Im gonna try with a 34mm manifold, and a powerfilter, and carbon reeds. a friend of mine have some carbon reeds i think, i can lend them, And when the shops starts opening again im gonna go ask for a 34mm manifold, and a powerfilter to fit.

miguelNS · DTR Respected Member

NorDt wrote:
Miquel, How fast can i make my dt go without any changes on the cyllinder ??. im not gonna do any changes on it.

And Yamaha dtr how wil it restrict my bike ?.

It wont go much faster as it goes now...

NorDt · Guru

I was talking to a guy, claiming he bench marked it at 31 bhp on 10500 rpm, with å 35 mm carb. Im going to the local mc Shops tomorrow to ask for å 34mm manifold and a powerfiltre

miguelNS · DTR Respected Member

NorDt wrote:
I was talking to a guy, claiming he bench marked it at 31 bhp on 10500 rpm, with å 35 mm carb. Im going to the local mc Shops tomorrow to ask for å 34mm manifold and a powerfiltre

31 bhp on the wheel? i only believe when i see it blankstare yawn