CHARITY BEGINS AT HOME
RICK ANSWERS YOUR QUERIES
Engineering student Harry Bott is making good use of his university gap year, doing a sponsored ride around the coast of Britain and Ireland in aid of the RNLI, stopping at every lifeboat station. The bike? Harry’s family 1926 350cc Sunbeam – bought new by his great grandfather!
Unfortunately, a piston seizure stopped play this month and, unable to find a replacement, his dad Richard asked me what else would fit.
As well as bore size, the crown and gudgeon pin height, pin diameter and width between piston bosses all come into this. Besides, the last thing Harry needs is to be running in a rebore for the next 1000 miles. Unless the piston is cracked, I’d just hone the bore, file the seizure ridges off the piston (working circumferentially not up and down, so the file marks act as oil retainers), clean up the grooves and fit new rings. Within reason, a slack fit is no bad thing for a hard-pressed engine; the little 350 is working very hard and seizure is a greater danger than rattles and a bit more smoke.
Although he didn’t sound convinced, a week later Richard phoned to say he’d done as I advised, fitting new rings from ring specialists Cox and Turner in Yeovil and the bike was running well. But there have been other issues, particularly with the beaded-edge tyres which aren’t really up to the mileage/load, so before long Harry will swap to Richard’s nextgeneration 1930 Sunbeam 500cc Model 9.
If you want to follow Harry’s journey he has a blog (rnlitour.blogspot.com) and if you want to donate to the RNLI in support of his tour, go to www.justgiving. com/fundraising/harry-bott