BGM ‘RT’ RaceTour 225 upgrade – Will Uni save the day? Part 2 | FEATURE

Thursday

We were all feeling lucky today, the Italian and Spanish Gods hadn’t been kind to us, so hopefully the Indian ones would be in a better mood. This ‘one-day’ job had turned into most of the week. My shop coffee making skills were coming along nicely though and it was good to be in a banter filled workshop instead of being sat on my own typing like a loser at SLUK HQ.

It’s the first time I’ve actually used a set of Uni casings myself and the quality is very good. We know there’s an issue with the end plate alignment when they come out of the factory but UK Uni distributors, AF Rayspeed, will fix that for you for a few quid before your casings get sent out. The ones we used had been sorted already.

Starting a build from brand new casings makes life so much easier. Everything is clean and fresh, all the threads are good and its one less thing to go wrong.

Third engine lucky?

Once bitten, twice shy. Rob wasn’t going to risk his luck a third time, so he built the top end of the engine first, the transmission side could wait. Bearings and seals in, crank in, mag housing on, top end on (no problems with the fat BGM studs on this casing. Holes bunged up… I’d be lying if I said I wasn’t a little nervous as we leak tested this one. Eureka! It held pressure like a good ‘un. We were finally getting somewhere.

Check your squish

It’s worth noting here that the squish on all three engine casings was different every time. Always check your squish gap (see video above) when building an engine, even if you’re just putting an existing top end back on.

The rest of the engine build went fairly smoothly, although we needed to grind one of the supplied BGM manifold bolts down to allow it to miss the lovely CNC machined manifold as we tightened it up. The 30mm carb rubber also came with a metal collar to sit between it and the jubilee clip but we couldn’t get that on. Only a minor issue but worth noting.

Gearbox fettling

Rob had a few problems getting the gearbox shimmed correctly this time (see videos above) and had the gearbox in and about half a dozen times. The stepped AF rear hub bearing also had to come back out to have a 0.5mm shim put behind it to allow some extra end plate clearance. He also had to swap the kickstart ramp after drilling and tapping new holes in the original chaincase side and grind some metal from the rear of the Uni endplate to allow enough clearance for the Clo5e 5-speed box.

The BGM Pro 6-plate clutch went together easily enough and worked perfectly without modifications. It’s a well made piece of kit and it’ll ring for ages like a tuning fork if you tap it – we were so impressed that we videoed it but the sound wasn’t on (sorry about that). We also used a BGM 19-tooth front sprocket to replace the 18-tooth fitted previously. Ideally we’d have used a 17-tooth sprocket but we were limited by the chain length we had available on the day, we needed a stretched 82-tooth chain but only had a new one so the final drive had to be compromised (we’ll get that sorted over winter). We also used a Casa X44 chain guide to tension the chain.