Curlew block waterways

[Chris Cornwall]

I'm drilling out the seriously blocked waterways on a QB Curlew block (good old salt !)
Not too sure where to stop

The hole above exhaust port successfully now clears through to water jacket

The hole below port curves round to lower side (opposite carb) and joins low down, does it also branch out to the carb side ?

The 'quarter' of water jacket furthest from exhaust flange doesn't yet connect round to rest of chamber....
Do I keep excavating ?

Thank you for any guidance

yours Chris L

[Hugz]

I asked the same question years ago. I too feared that I'll be grinding out metal. I backed off and tested to find a good water flow. I wonder if the apprentices have sliced a curlew block?

[Charles uk]

Only use a long thin masonry drill bit for this job, they will penetrate the clag but not the cast iron.