Cylinder Head

Well, what happened was..... I was at a track with Ricky Bearcroft and he knew that I had swapped motors and he advised putting my RRSP head onto my RR motor that I was now running. The SP has better springs and lighter buckets, not sure if the cams are different or not. Well as I was taking the head off anyway, would I be interested in letting him have it to tune it a bit? A bit of porting and a smidge of skimming, all at a bargain price (just tools and materials). Well, it seemed too good an offer to refuse.

First task was to take the head off the RRSP motor that was sitting under the bench. Luckily, this was before Darren and Pauhla Hill had buggerred off to France, so Darren came round to help me out. Plan was for Darren to show me where bits came from and I could take a few pics while he was doing it. Downside was he was bloody quick with the spanners. He'd say "this is important, you've got to torque these up", so I'd grab the camera to take a photo and when I looked round he'd have the part in his hand. Two minutes later, he'd say "have you got a 10mm spanner?" so I'd turn to get one and when I looked around he'd have another part in his hands. Anyway, he soon had the head off, I'd taken some pictures and I assured him I'd been paying attention (yeah, right). He later told Glen to make sure that I got someone else to rebuild and refit the head cause he didn't reckon I had a clue. Cheeky git!

He didn't have his valve spring compressor tool with him so he took the head away to strip it at work. I collected the bare head and a box of parts later and gave Darren a bit of cash for his help (first extra bit of expense not included in the 'to good an offer to refuse' amount). Darren said that all the inlet valves were tulipped(?) and really could do with replacing, a common Yam problem apparently. I couldn't see anything wrong but then I wouldn't know what a good one looked like so 112 later and I had some new ones. Compared new to old and I still couldn't see a difference. Told Darren, he's now even more convinced that I am mechanically inept. I ordered a new head gasket and a new cover gasket as well, something like 25 was it(?) I forget. Or it could be denial.

Anyway, I gave Ricky the head and he attacked it with his Dremell-type-thing. He then gave it to a mate who skimmed 10/1000's off it, a nice safe number. Well they told me it was a nice safe number, being a complete engineering buffoon I put my trust in those in the know. I then went to visit it and lap the valves in. This involves turning the head upside down and putting a valve in. You smear the valve with some grinding paste so where the valve head meets the valve seat (the head) you sort of sand it down. To do this you attach a valve tool to the valve, its like a piece of wood with a sucker on the end, like a mini-plunger. Then you rotate the wooden handle in your palms by rubbing your hands together like you would to keep them warm. This turns the valve clockwise and anti-clockwise, which rubs the paste in between the valve and the valve seat and after a while you get a nice even coloured ring, which means you've got a good seal. Every two minutes you stop, check, ask the engineering gurus (Ricky and his dad Dave) if its okay and keep going til it is. Took me 5 hours to lap in 16 valves. My feet were killing me!

Time to re-assemble the head. Did I tell you Darren had moved to France? Well, it all looked a bit complicated, there were lots of little parts and it looked dead fiddly. So I got someone else to do it. Dave Bearcroft in fact. I'm no in debt for a lot of favours...... I dropped the motor out of my bike and delivered it to Daves and a week later and I was collecting my assembled motor and a box of spares. Eventually I got the motor back in the frame, not sure whether to add that Mark Mitchell (aka Dodgyhaircut) helped seeing as he spent most of the day drinking tea and gassing with Rob Jones about R6 suspension. Anyway, once the motor was in the header pipes wouldn't clear the wheel. Rob Jones said his mate Adey Ridewood would be able to fix that so he gave me Ades number and I got that sorted (see exhaust page). Once they were back, the bike was put together and it fired up pretty darn quickly. And sounded sweet (and very loud). Time to get to the dyno to see if I can get the pipe to work with the head...

If you want a quote for any tuning work, and you're either in the Gloucester area or are happy to ship it, then e-mail Ricky Bearcroft.



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