John Oliver (AKA Yoshi-Johnny, AKA YJ) is a long time OSS member and Pops Yoshimura enthusiast. John is a professional bike mechanic and many will remember his iconic take on the classic Wes Cooley GS 1000. Ten years ago, when John first rolled up at an OSS gathering on his GS, for me and many others, at the time, his bike fully embodied the true spirit of OSS. An air-cooled 8 valve GS1000 engine and classic Wes Cooley paint job but running on modern 17″ wheels, sporting a mono shock conversion and a set of gold anodised upside down GSXR forks. Evolution of the species. John’s love for Suzuki’s 8 valved air-cooled GS1000 engine has never faded. We asked John to tell us a little about his dream engine build and here is what he told us.
Oldskool Oldskool, the road less travelled. John Oliver
It’s always been a dream to own a full blown Yoshimura motor but I don’t earn enough to just go out and buy one so I am gonna have to do it the only way I know how, a p.p.p.piece from here and a p.p.p.p.iece from there. So, I am in the process of getting together for the race bike I am going to prep for myself to go racing instead of others!
I got hold of an old NCK drag motor a few years ago and it has a pretty good crank and gearbox in it. Crank has Katana rods and along with being welded it has straight cut primary drive gear, along with a matched one for the clutch basket. Cases have been lightened and dipped at Ribble Technologies in Preston. So the bottom end is as good as my budget will allow for the moment. I do need a new clutch before it turns a wheel in anger and this will involve having the straight cut fitted. Originally the NCK engine was a 1420 drag engine but on the road or track that sort of capacity would generate too much heat and quickly cook itself.
Graeme Crosby in conversation said he preferred the power and reliability of the 998cc motor as it gave enough power and was reliable, Pops and he discovered the bigger the capacity went up, the less reliable and problematic it all became. Craig Smith, my good mate in Australia who has been on here for years is a major inspiration for the build as his black “skunk” race bike is still one of the outstanding bikes on the site. He raced it to good effect in NZ and didn’t suffer with reliability issues. He went bigger and bust his crank!His motor punted out 135 rwhp and that is my aim with this… I won’t be gutted if it doesn’t get there, but it would be nice if it’s something like.
So the pistons are custom made 1100cc Wisecos and are one of only 3 sets made this particular profile I think. All the gaskets and seals will be replaced with standard (where necessary) or Cometic (where it’s ok to cheat!) and special ones (base and head).
The cam chain was a weak spot on Yoshimuras race engines and the team did all sorts to try and reduce the extreme wear during races, extra jockey wheels, longer cam chain, shorter tensioner blade, POLISHED cam chain links and manual tensioner were all employed in the hunt for reliability. Most of this development actually went into the first GSXR engine. So all the above mods will be done to this engine.I have had a jockey wheel and plate made but Roger Upperton does a better version which is more like the GSXR version than the one I have. The extra jockey wheel at the back of tthe head is the reason the tensioner blade is shortened.
The head has been checked over and overhauled from scratch. Bigger valves, seats cut to match and a tidy port job will make the gas go in quick and hopefully make it work right.
Cams are very lumpy custom profile ones from New Zealand and require cut aways for them to turn in the head! Shims will be under bucket care of Kibblewhite, buckets, retainers (titanium) and collars. Dialled in cams will be easier with Rogers version of the jockey wheel than the Smithy version. I may put a twin plug set up in as well when I actually get to the build
Carbs will be Mikuni VM33s and are getting quite scarce, these are about as big as you should be going on a bored out GS1000 engine, anything bigger just makes them bog down when you crack the throttle open.
Ignition will be taken care of by Boyer Brandsen mini digital set up until I get a self generating system organized…
Speed is all a question of money…I wanna go fast but my wallet says whoaaah.