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CB250 and Welsh Hills.

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scifi:
I was at a Vintage Machinery Show near Corwen, and thought I would take my CB250 up the nearby Berwyn Mountain track.
All went OK for the first few miles, but as the road surface became more rocky I had to slow down to navigate a good line.
As soon as the revs dropped below 5000 rpm the bike just died and stalled out.
This is the sort of track that I have ridden on an old British 4 stroke single, and thought no more about it.

 I now have a list of hills to avoid in the N Wales area, on this type of bike....  It's just got the wrong type of power.

Johnwebley:
Check the tickover


Should pull as low as 3k

My little 200 twin will pull that low

Sent from my SM-A546E using Tapatalk

Bryanj:
Nonheavy flywheels for bottom end grunt

TrickyMicky:

--- Quote from: Johnwebley on July 19, 2026, 09:42:46 PM ---Check the tickover


Should pull as low as 3k

My little 200 twin will pull that low

Sent from my SM-A546E using Tapatalk

--- End quote ---
   If my memory serves me correctly, the 200 is a 360 degree twin, whereas the 250 is a 180 degree. I think back many years to my 175  twin with the 360 crank, and it would run to reasonably low revs, but my 250 needed to be kept spinning over quite quickly.

Oddjob:
You’ve got to rev these small engines to get them to pull hard. Keep around 7k and use the gearbox is my advice.

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