Hi! I've recently bought a Dt125RE converted to supermoto, it's got Excel rims front and back 120/70 and 140/70 .

And im wondering how it will affect the handling if I install a 150/70 tire in the back.

And im also having some issues with my powerband, my bikes tops out at around 140km/h (gps) but on most gears it lacks power at around 7000 rpm, it doesn't bog but just doesn't wanna KICK, like it does by 8000k rpm and 6000.

.

Thanks!

Sounds like you have the 'X' model. Supermoto from factory, same as the RE but different spring rates and a bigger front disk.

 

Tyre wise I'd stick with stock sizes, going bigger on the rear will make the handling worse.

 

As for the power, have you checked and tried the simple things? Air filter, fresh plug for a start. Then you need to look at power valve adjustments, exhaust leaks etc. If it pulls at 8k but not at 7 then you could potentially have a carb issue, you could try setting that back to standard if you think the jets haven't been tampered with

Thx, opened the carburettor a week ago an cleaned it, turns out it had a 250 jet.

I think ive got some air sneaking in where its not supposed to be, i only works if the air screw is all the way in. I have a clean filter, new spark, no exhaust leaks whatsoever.

Standard is a 210 jet.

250 sounds massive. How does it idle? If its pulling air in from somewhere the idle would be really high

Well the idle is fine when its hot, but cold it barely idles, thinking about it I really need to switch jets....

What exhaust are you running?

I have a full dep system on mine with standard jetting and standard settings and it pulls all the way to max revs cleanly.

I don't think you'd need a 250 main unless you did serious head work etc

 

I'd get a 210 main jet, clean the carb and put the settings to standard and go from there

I've got a gianelli full system, along with an Athena 125cc cylinder, derestricted I think 

250 is bigger than you get in a tdr 250, way too much. We were only using 220 maybe 230 in fully de restricted 30hp tzr's back in the day.

I think people with the 170cc kits run 240ish jets