Mugello 225 into 240 possible

[Thackers]

Hi, I'm thinking my Mugello mk1 225 will soon be towards the latter stages of it's life. It's on a C piston so could the cylinder be turned into a 240 or is that too much to expect?
If it's a reasonable idea (i know there are some muggy 240's out there) what parts would I need to change please? Crank? Cyl head ? I understand the replate and new piston is required along with a re bore.
I just thought it might be an option instead of buying another kit
Thanks for any advice you might share

[Rich Oswald]

Hi Dave,

I had a Muggy 225 V1 in my GP for many years and it served me well for thousands of miles and rallies. It lost a lot of power eventually and I took it to Martin at Chiselspeed who told me that the port timings were terrible on these V1's. He did some porting work and with a new piston and rings it lasted a few more years until Exol oil killed it off. That was my conclusion anyway as the rings wore down rapidly and stuck in the grooves.
Just my opinion, but I think you have reached the end of the road with your cylinder and you would be just wasting your money spending on it. It would work out far cheaper to just buy a new kit, and the RT225's are superior imo. To go 240cc, you would need a replate, new piston and rings, new head or major work on your old head. You would need a new crank 64/110 ( not 100% on that size) but that would need crankcase work for it to fit. A lot of work and money for an old cylinder imo.

Rich'

[Thackers]

Thank you Rich, that's very good information and really I couldn't ask for better insight. It was just a theory so no real disappoint. It's very good of you to reply.

[Toddy]

Maybe replate and go back to A grade piston , maybe worthwhile before plating looking at any tuning or maybe a Reed conversion?

[Rich Oswald]

Maybe replate and go back to A grade piston , maybe worthwhile before plating looking at any tuning or maybe a Reed conversion?

More good advice David.

Rich'