CB250RS Rebuild Progress

[K2-K6]

Cautious optimism then, hope it's going to run without issue this time.

To be ultra cautious regarding running hot if that's the case. Worth considering the plug temp grade given that it holed a piston in one of it's previous builds.
Overheating the plug tip can lead to pre-ignition which puts the piston crown at risk.  I wouldn't run the lower range 7 NGK choice but either 8 or even 9 if that's in the manual for this engine.  Don't know what you've got in it but the higher numbers will give you more safety margin if they run ok.

[Laverda Dave]

I have an 8 fitted at present Nigel but may go up to a 9. What I am making sure of doing is planning my route where I don't sit in traffic. I'll stick to riding around the Chalfont/Amersham and Aylesbury areas until the engine is properly run in.
James, I'm using mineral oil, I don't think I'll run this engine on a semi synthetic. As the engine only holds 1.5litres of oil, runs hot and works hard I'll change the oil every 750 miles to give it (and its owner!) an easier life.

[Nurse Julie]

You deserve for it to be OK, you have persevered above and beyond. I hope it keeps going well for you.

[Laverda Dave]

Thanks Julie. My fingers and toes are crossed this time!
I cannot belive how much quieter the engine is though following the latest rebore, its a different bike!
I'm sitting on a train on my way to Westenhanger now to collect the fairing. I think I'll be sending it to Menno for a respray to match the tank etc he painted last year. Just wish I could find the engine bar.

[McCabe-Thiele (Ted)]

An agonising read Dave - in a way I understand why you parted with the bike though not sure what the time gap was between this thread and it's eventual sale.

[Laverda Dave]

It was 5 years Ted, it ran like a dream once it was rebored properly and I replaced the drive seal, a real hoot to ride🙂.
A bike I regret selling especially after 20 years ownership but I had no room to keep it, a recurring issue now, I need to rent a barn😁