Hi
What is the top speed of a 1977 Yamaha DT 125E type 1G0?
What is the maximum speed to keep the engine from breaking down?

If I rebuild it to 175cc how much will the engine power and speed increase?

Will taking the baffles out of the exhaust to leave just the wrapper literally have an effect on the power increase as well.
Thank you typing via translator from Europe Czech Republic.
Daniel

I know you have a few different post going on the site & you've probably seen my ugly old AT1 [175 top end] from an earlier post tonight that i linked.
I see this post not answered so i'll fill it up with a couple of videos [sorry haha] which might give you an idea of performance upgrade between you 125 & my 175 [that was a 125]. I have 'very high gearing' on it because its such a willing motor. Two videos coming if i can work it. First video the clutch obviously slips quite bad. But second video around the track it stopped slipping. I must've burnt the glaze off the plates, or the rust from sitting for a long time.
Videos coming soon.

Drag the second video along as is pretty distant & boring but just to show how it accelerates as a 175.
Drag both videos along as go on for a bit. First one i should have to write out 100 times--i must not rev the poor old bike that hard--haha.
Mine is magneto ignition not electric start.