exhaust restricted?

[speedjunkie20...]

Does anyone know if the big one exhaust for a dt 125 comes with a restrictor or not. my bike is still only hitting 65 70 with a big one exhaust, and powervalve opened.

[Kickstart]

Hi

Not certain but would think it is very unlikely.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[redline]

None of the ones I have ever had did, they are an expansion chamber. Have you got the front pipe and tail pipe? If you have you could experiment with different sized jets, although you shouldn't necessarily have to do this, otherwise you could try a different front or rear sprocket

Hope this helps

[Jamie S]

As a side note, Whats a realistic top speed for a DT ?
Ive got a 1999 dtr, fully functioning power valve , reducing washer took out from the very front of the spanny and the airbox snorkel is took off.
It will sit at 65/70 , can be pushed to show 80 on the clocks given a slight gradient and long enough road.
Going to stick it on the dyno soon to see what bhp its making, what would be about right for one ? around 20 odd ?
Regards, Jamie

[That_Hornet]

https://www.dtr125.net/

[prawny1]

are you reaching red line in top gear?

if so try a bigger front sprocket, it will give you a little more top speed if your still revving out try a tooth smaller on the rear

[Kickstart]

[stevo as b4]

It does depend on the gearing TBH. It should be geared for 80-85mph at 10.5k i would have said. You would expect around18-20bhp for a full power DTR at the back wheel, but it depends on if you have other mods like an aftermarket pipe etc.

With full power versions you can usefully raise the overall gearing slightly for more speed. All trail bikes are compromised by their std gearing. The KMX125's will do another 5-6mph with just a 1t bigger front sprocket for example.