OzVMX Forum
Clubroom => Vintage Track => Topic started by: firko on March 12, 2013, 10:54:14 AM
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As most of you know I've got a big love of American flat track bikes and own a couple of two stroke Yamaha examples and have been slowly assembling the parts to build a Trackmaster XS650 and a replica of Gene Hartline's 650 Benelli flat tracker of the late 60's. The latter two projects are now on hold and will probably be sold because I've fallen upon something very special.
I've managed to buy a genuine Shell Thuet OW72 750 Yamaha flat tracker, a bike that's so rare they very hardly ever come up for sale, this is the Dirt Track equivalent of finding an OW motocrosser. The bike was being sold by the widow of a good friend in Las Vegas and although I had no plans for any more bikes until I finished my current projects, this bike shone like a beacon and I just had to have it. A Shell racer with a production based motor recently sold for $9000 at auction and a genuine works OW powered bike sold a couple of years ago for $22000. I paid $3700us for mine in dismantled but fully restored condition. My friend Bob was in the process of assembling the bike when he suddenly died three years ago. The engine has been fully refurbished by a known specialist, the frame re-nickeled, the wheels rebuilt and the bodywork freshly painted in factory Yamaha colours. I've been assured by the seller that all of the major parts are there, the only things not found so far being the seat pad and Grimeca rear brake, hanger and Barnes wheel knock off hardware. There's a possibility that Bob had sent them out for refurbishment and unfortunately died before picking them up.
From what I can find out, the OW72 750 engine shares no parts with it's XS650 production brother. The transmission is close ratio handmade by Webster, the clutch is titanium or magnesium, the crank cases are cast with better material and feature additional internal webbing to handle the big HP, the crank is lighter, Carillo rods and Shells own pistons and camshaft are used and the head is a special casting with different angled inlet tract and different valve angle+bigger ports, the ignition is YZ/OW motocrosser based and a lot more stuff I'm yet to learn.
I'm about to enter into a big a learning curve on these things so once the bike is safely out of the US I'll be contacting those in the know. Unfortunately, the creator of these bikes and the head of the Yamaha flat track team at the time Shell Thuet died a couple of years ago aged 98. Thankfully there are a number of folks who know a bit about OW72 engines so they'll be getting a hammering from me ;D The bike has Ceriani forks, Barnes wheels, Shell frame and bodywork, S&W shocks (Shell Thuet was th S in S&W along with Tim Witham. Every Shell has S&W shocks fork springs and valve springs of course) The pipes are 1.75" reverse megaphone tuned length thin wall items and there are no silencers so we'll have to cross the noise bridge when we get to it. As rare as this bike is, it will most definitely be raced in the twins race series and anything else it qualifies for. It's ironic that fellow Klub Kevlar Komrade Fast Eddie Phipps owns the ex Eddie Lawson OW72 Shell, an almost identical bike to mine, the only two OW's outside of the USA that we know of. http://vft.org/Memorial/Shell/ShellThuet.html (http://vft.org/Memorial/Shell/ShellThuet.html)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG00131_zpsf8683deb.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0011_zps5f7cf2bc.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0009_zps3072a625.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0012_zps48002ad8.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0014_zps43d8f8ba.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0016_zpsf5bd4941.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0021_zps4a40f848.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0024_zpsc7da7cb5.jpg)
Below: Tom Hortons identical '74 works Shell OW750
(http://i1112.photobucket.com/albums/k495/firko2/12Dec07ShellYamaha-1-LS_zps628567ae.jpg)
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Sweet!
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Wow! :)
Top score Firko,
shame about your friend though.
you'll need to keep Freaky away from your door now...
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mark
nice one
i have been doing some digging on a gen pre70 750 flattracker as well.now just those pesky rear disc brakes to sort out dates
jim
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(http://i1112.photobucket.com/albums/k495/firko2/shellthuett_14syracuse0975_zps270f82f8.jpg)
http://superbikeplanet.com/2011/Jul/110713shell.htm (http://superbikeplanet.com/2011/Jul/110713shell.htm) http://sliderulemuseum.com/ShellThuet/Shell_Thuet_Biography.pdf (http://sliderulemuseum.com/ShellThuet/Shell_Thuet_Biography.pdf)
Still Kickin'
by dean adams
Tuesday, August 14, 2007
A true legend in dirt track racing, Shell Thuet turned 95 earlier this month. You may have heard of his former riders: Kenny Roberts, Eddie Lawson and Wayne Rainey.
image by dennis kanegae
Shell Thuet's life spans the eras and generations in motorcycle racing. A famed engine-builder and tuner, his involvement in American motorcycle racing began in the 1930s and, impressively, he was still a fixture in dirt track racing over fifty years later.
While infamous for a gruff personality, Sheldon Thuet was respected by the best and fastest racers from the 1940s through the 1970s. He built fast motorcycles for at least two generations of riders. In the modern era, Thuet became the de facto Yamaha 650 Twin tuner in the dirt track ranks.
Riders who used a "Shell Racing Specialties" Yamaha to tear it up on dirt tracks the country over include Wayne Rainey, Hank Scott, Gene Romero, Keith Mashburn, Donnie Castro, Eddie Lawson, Tom Horton and, of course, King Kenny Roberts.
While nearly all of the tuners of the 1940s have joined Smokin' Joe Petrali in the big paddock in the sky, Thuet, amazingly, recently celebrated his 95th birthday.
It's exiting to think that one of the above legends may have ridden my bike. There'll be a bit of research going into this once I get it.
(http://i1112.photobucket.com/albums/k495/firko2/Shell4_zps7fe39452.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/Shell9_zpse368a836.jpg)
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very nice addition..
do you have a picture of the Gremica caliper?
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Mmmmm the cream!!!!!!!!!!!!!!!!!!!!!!!! What a fantastic pick up Mark :D Cheers
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very nice addition..
do you have a picture of the Gremica caliper?
My mistake.....The rear brake is actually made by Kennedy Mfg as listed in the cattle dog page on my previous post and best news of all, it's shown up along with the original back wheel which also comes with the bike. The missing Barnes quick change tackle is there as well.
(http://i1112.photobucket.com/albums/k495/firko2/CIMG0829_zpsce694080.jpg)
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Great work Uncle Firko.
Anything works is very cool -Well Done!!
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Good score, howdya beat Jonesy to it?
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Good score, howdya beat Jonesy to it?
She offered it to me first....he'd have grabbed it if I hadn't, Jim would have too.
Here's a good piece I found on the OW72 heads. http://thexscafedotcom.wordpress.com/2011/09/13/xs650-ouow72-heads/ (http://thexscafedotcom.wordpress.com/2011/09/13/xs650-ouow72-heads/)
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Great get Mark!, You and Fipps will look great battling it out at Nepean!
Cant wait to see that!
cheers.
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What an awsome piece of gear, gone to a good home. Shame another enthusiast had to meet the reaper for it to happen though. Keen to see the end result of your assembly Firko!!
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Thats really nice Firko,
I bet thats your friend would have wanted, i know i would...
goood luck to you mate.
Let us know when its gunna run at Nepean.
Maybe you should look up Kel Coruthers
Brett
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(http://i49.tinypic.com/2jebhft.jpg)
Firko that swingarm looks a dead ringa of my Redline swingarm, are they made by both the same frame builders ???
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Firko that swingarm looks a dead ringa of my Redline swingarm, are they made by both the same frame builders
you spotted it one....Redline made Shell frames to Shells Thuets specs.
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I've been digging around looking for info on OW72 and OW79 Yamaha 750 engines and came accross this snippet...In relation to your cylinder head rocker box the engine you are referring to is an OW-72 of which 25 were made in 1974 for flat track racing in the US. which makes this find even more exciting as it puts the engine and possibly the bike legal for pre 75! For anyone interested in what the OW72 head looks like when compared to a stocker, her's an old piece I found.http://users.skynet.be/fgeers/MyMotorcycles/Pages/TechOW72.html (http://users.skynet.be/fgeers/MyMotorcycles/Pages/TechOW72.html) Apparently the development work was done by Toyota which is an interesting connection.
Here's the link I posted to the OW72 transmission that was recently for sale on vft.org. http://ozvmx.com/community/index.php?topic=27676.0 (http://ozvmx.com/community/index.php?topic=27676.0)
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I'm on a bit of a roll after the big 750 fell on my lap. I couldn't resist this little gem on eBay for $500. I happen to have a low mileage 305 Honda Dream motor gathering dust in the shed so.....why not ;D
(http://i1112.photobucket.com/albums/k495/firko2/cates_zps896326f4.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/cates2_zpsa146cefd.jpg)
Up for auction is a very rare and unique item. This is a Tom Cates Flat Track Racing frame. It is made specifically for the Honda CL72 engine. Of course a CL77, CB72 or CB77 engine will also fit. Tom Cates started producing these frames in 1962. This frame is in overall good shape, has surface rust but should clean up nicely. The frame is straight. There were only ever a handful of these frames ever made, I believe less than 100. As you can see in the pics the engine mounts are about 2 inches over to the right to help give ground clearance for turning. Includes triple trees, the triple trees are for the stock CL72 forks. A lot of the parts you will need for this are pretty much universal fitting from other flat trackers such as the tank, seat and wheels. This would make for a good project for any flat track fan or a Honda fan that wants to build something truly unique. Here's a complete one that was recently for sale.
(http://i1112.photobucket.com/albums/k495/firko2/catesHonda3_zpsccec7904.jpg)
(http://i1112.photobucket.com/albums/k495/firko2/cateshonda2_zpsd6b11af6.jpg)
http://powersports.honda.com/experience/articles/090111c080a4ad9c.aspx (http://powersports.honda.com/experience/articles/090111c080a4ad9c.aspx)
http://www.motorcyclemuseum.org/halloffame/detail.aspx?RacerID=376 (http://www.motorcyclemuseum.org/halloffame/detail.aspx?RacerID=376)
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I picked up the Tom Cates CB72 rigid frame pictured above today and can't believe how light it is. I might lay it out and do a dummy build to see what I need later in the week. I've already got the 305 motor, f/glass tank and seat almost identical to that on the red bike and will use DT1 steel forks and possibly a DT1 rear wheel (mainly to use up shit laying around the shed). I've also got a spool front wheel already fitted with a Carlilse an d even have enough candy apple red left over from the Yamaha so it should be a cheap build.....(famous last words)
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Some lovely gear there Mark Im going to have to come up to NSW to see some flat track . Last time I was at Nepean was for the lisa Ricters and Herb benefit .
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As of this afternoon, this little sweetie is now tucked away in its new home at Casa del Firko. Once I've unpacked everything and checked it all out I'll post some photos. Then.....the build starts, I can't wait ;D.
(http://i1112.photobucket.com/albums/k495/firko2/Shell_1_zpscab9c6d4.jpg) (http://s1112.photobucket.com/user/firko2/media/Shell_1_zpscab9c6d4.jpg.html)
Packed in with the 14 boxes of Shell Yamaha was one box containing the 750 Trumpy engine destined for my Trackmaster frame, replacing the sold 650 Benelli motor that had sat in it for the last few years. That project can wait a little while though ;).
(http://i1112.photobucket.com/albums/k495/firko2/Trumpy_zps6f29a567.jpg) (http://s1112.photobucket.com/user/firko2/media/Trumpy_zps6f29a567.jpg.html)
(http://i1112.photobucket.com/albums/k495/firko2/ATrackbenelli_zps4e5c3f50.jpg) (http://s1112.photobucket.com/user/firko2/media/ATrackbenelli_zps4e5c3f50.jpg.html)
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Shell Thuet was th S in S&W along with Tim Witham.
Actually, Art Sparks (who founded Forged True pistons) was the S in S&W.
cheers,
Michael
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Actually, Art Sparks (who founded Forged True pistons) was the S in S&W
There you go, my medication has struck my memory again ::).....Thanks Michael...I was fairly sure I'd seen it mentioned a couple of times that it was Shell Thuet but I'm glad to be corrected. That's the beauty of forums like this....no matter how much we think we know, there's always somebody out there to proof read our stuff ;D.
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As of this afternoon, this little sweetie is now tucked away in its new home at Casa del Firko. Once I've unpacked everything and checked it all out I'll post some photos. Then.....the build starts, I can't wait ;D.
(http://i1112.photobucket.com/albums/k495/firko2/Shell_1_zpscab9c6d4.jpg) (http://s1112.photobucket.com/user/firko2/media/Shell_1_zpscab9c6d4.jpg.html)
Packed in with the 14 boxes of Shell Yamaha was one box containing the 750 Trumpy engine destined for my Trackmaster frame, replacing the sold 650 Benelli motor that had sat in it for the last few years. That project can wait a little while though ;).
(http://i1112.photobucket.com/albums/k495/firko2/Trumpy_zps6f29a567.jpg) (http://s1112.photobucket.com/user/firko2/media/Trumpy_zps6f29a567.jpg.html)
(http://i1112.photobucket.com/albums/k495/firko2/ATrackbenelli_zps4e5c3f50.jpg) (http://s1112.photobucket.com/user/firko2/media/ATrackbenelli_zps4e5c3f50.jpg.html)
I'm DROOLING Mark..........As you know, Yamaha and Triumph are my mounts of choice......BEAUTIFUL !! :P :P
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OK Mark, enough's enough. I don't know about everyone else but you're killing me here. Photos, pleeeeese ;D ;D
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Nice find Mark, the OW looks like a very special piece of kit,being a welder i love looking at the quality of the frames,swingarm's etc.
cheers Dale
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So it made the trip unscaved. Well Mark, if something happened to me i would like a good mate or two of mine to be as passionate as you have with your old friends bike. Can't wait to see it at Nepean one day!
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I'll run off some photos tomorrow. Remember that it's in a squillion different pieces so all I can do is photograph everything in a sort of dummy set up. Then everything goes away until I've finished up the last few little things on the Cheney and the red flat tracker. Getting them ready for Temora is my first priority. I'll probably make a start on the 750 sometime next month.
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This rare, one off Trackmaster prototype frame to suit an XS650 Yamaha will slowly go together as well, now that it's confirmed that a mate is selling me a stock XS650 motor (see mock up above with its previous 650 Benelli Tornado motor). I've got most of the parts needed to get it on the track including Yamaha R6 forks, Morris magnesium wheels and a few different variations of bodywork. With a bog stock electric start 650 this bike might suit slow old fart me a tad better than the Shell which will be ridden by Yamaico Pete and/or Steve Gall at the big meetings. The 650 Trumpy motor will now go onto the shelf waiting to eventually be built into a pre 65 motocrosser project.........probably about 3 years down the track going by my current shed output. ::)
(http://i1112.photobucket.com/albums/k495/firko2/09-11-30-InfoAusTrackmaster4Benilli1_zps4903e2e8.jpg) (http://s1112.photobucket.com/user/firko2/media/09-11-30-InfoAusTrackmaster4Benilli1_zps4903e2e8.jpg.html)
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Mark, when helping a friend with an XS650 project I discovered that the rotor from a 3 phase external rotor alternator from a Kawasaki EX250 fits as though it were made for the Yamaha. It is an "inside out" setup but it isn't that hard to make a plate to hold the stator in the outer case. He only used it to generate power as he already had a Rita ignition off the cam. It seemed a good improvement over the OEM generator.
You can see some photos of the installation in this folder along with some photos of the bike (modified CBR600 frame and swing arm, Ohlins from a Husky, GSXR forks/wheels/brakes):
http://www.eurospares.com/graphics/steveyamaha/
cheers,
Michael
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EX by their common name are GPX or ZZR in Aus. Neat fit!
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Thanks Michael, that's very a interesting and neat conversion. I'll look into it once I've got the stock engine home.
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Here's some quicky shots of some of the stuff hastily laid out. There are many other parts I haven't photographed. There are two sets of bars with different sweep and bends, new and used K&N filters, spare ignition, all of the engine plates, Grimeca disc brake hanger and footpeg plates have been polished and the gear lever, brake pedal and other odds and sods that I'm not sure what they're for have been rechromed. Gear and footpeg rubbers are all NOS Bates items. All of the original bolts are supposedly there but I'll replace them all with polished stainless steel items. I won't know until I start assembling the bike but I think about 95% of the parts are there. I'm in love with this beasty already ;D
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack003_zpsf8e738ec.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack003_zpsf8e738ec.jpg.html)
The engine. The 34mm Mikuni's and spare ignition and side covers are in a box.It's too heavy to lift up onto the bench so I'll get a mate to help me tomorrow.
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack014_zps4f750ea6.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack014_zps4f750ea6.jpg.html)
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack013_zps2de5bcd8.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack013_zps2de5bcd8.jpg.html)
Blurry shots showing new wheels, originals and Triumph Bonny twin leader I'll use for dirt track.
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack017_zpsdd018f74.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack017_zpsdd018f74.jpg.html)
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack018_zps74bef02a.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack018_zps74bef02a.jpg.html)
The fibreglass is brand new ethanol proof and the paintwork is superb. Bob definitely spent some cash on the showy stuff.
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack025_zps8a17b00b.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack025_zps8a17b00b.jpg.html)
Pipes are unused NOS genuine Shell that have been powdercoated Satin black
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While I was in the yard shooting the Shell 750 I laid out my other little side project el cheapo short tracker for some photos. The frame is a Fasttrack single downtube short track item that I swapped the forum's Jim an Antig Yamaha 2 stroke slider roller for, the bodywork is (I think) Trackmaster with flashy flame job I got for $50 off eBay a few years ago that previously lived on my Hindall flat tracker (which is destined to become a motocrosser again). The TM Suzuki is the partially dismantled remnants of the VMX Magazine elCheapo project bike from over a decade ago. It will donate its motor and rear wheel to the tracker and the rest sold off (without the Curnutt shocks) to help pay for cables, tyres and other items for the tracker. In the foreground is the surface rusted but unused Circle F pipe, shortened Bultaco Betor forks and mystery 19" front wheel that'll be mounted with a Carlisle tyre. This is one of my classic bargain basement projects, for every bling bike I build I like to counter it with a cheap and cheerful project built out of stuff I've got laying around the shed. The bike, once it's built and will be "permantly loaned" to a Klub Kevlar mate who's doing it a bit tough right now. I think it's going to turn out a sweet little bike for under $1000 outlay.
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack011_zps85f4c69c.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack011_zps85f4c69c.jpg.html)
(http://i1112.photobucket.com/albums/k495/firko2/shellampfastrack006_zps75c73111.jpg) (http://s1112.photobucket.com/user/firko2/media/shellampfastrack006_zps75c73111.jpg.html)
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I finished dismantling the RM250 this morning and seeing that everything was close by, I couldn't resist trying the Suzuki motor into the Fasttrack flat track frame. Sometimes fitting engine A into frame B can be a real pain in the arse but other times they fit in like a cock in a sock. This is one of those occasions. The rear engine mount is a Champion style cradle and it comes so close to having the mount holes line up it hurts. The mount is even shaped to go around the engine casting in the kick start area. The top mounting hole lines right up and the bottom one would but for the need to gring a little bit of a crankcase rib away. The front fits straight in although the photo shows it looking as if it needs to go forward an inch or so. Once I've ground the case for the bottom rear to fit, the front mount should line up. It appears that the bottom front mount isn't bothered with.......so the verdict is that this frame is actually made to fit a TM250 motor....how arsy is that?? ;D. I'd planned for some major mount fabrication but it won't need any....Wooo Hooo ;D ;D
The need to grind the case for clearance interests me as if all cases were the same they could have cut a relief into the cradle mount. My engine is a 1976 TS250 bottom end with a TM250 cylinder of unknown vintage. My question therefore is....Are the case castings on my '76 TS engine different to those of a TM250 J-M? It's not a biggie but my curiosity is aroused.
(http://i1112.photobucket.com/albums/k495/firko2/wheelandtm250Fasttrack006_zps1d1b3c3c.jpg) (http://s1112.photobucket.com/user/firko2/media/wheelandtm250Fasttrack006_zps1d1b3c3c.jpg.html)
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Use the engine wedged between the two filing cabinets.
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Shithot Slides, yeah Firko,....see if that one fits as easily :D
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HELL YEAH!
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Use the engine wedged between the two filing cabinets.
It's for sale....C CODE 289 from a Mustang with quite a bit of go fast stuff. $1500.
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I just got my new number plates for the OW750....Cool........... http://www.flattrackstore.com/Fast-Plates.html (http://www.flattrackstore.com/Fast-Plates.html)
(http://i1112.photobucket.com/albums/k495/firko2/008_zpsdc345c8b.jpg) (http://s1112.photobucket.com/user/firko2/media/008_zpsdc345c8b.jpg.html)
....And he threw in a dozen 80x65mm stickers
(http://i1112.photobucket.com/albums/k495/firko2/005_zpsd68e7bc8.jpg) (http://s1112.photobucket.com/user/firko2/media/005_zpsd68e7bc8.jpg.html)
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Hey Mark,
Have you opened that motor up yet?
Pete.
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No Pete, too busy getting the other tackle finished for the Nats and pensioner care duties.......I'm not making a start until the workshops cleared of all of the current projects, I don't want any distractions once I make a start on it.
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Fair enough - you're a better man than me though. I don't think I could bear to have that in my shed and not work on it. I'll wait patiently for any developments...
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Its true pete its in the garage
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Fair enough - you're a better man than me though. I don't think I could bear to have that in my shed and not work on it. I'll wait patiently for any developments...
Pete, one thing I've learned from my time on the sidelines sick is patience. As much as I'm itching to make a start on the bike, I have to be patient and finish the projects I've got in the oven first otherwise I end up with a shed full of half finished, unfulfilled dreams. I've set down next years HBBB for the OW72's debut and I'll move mountains to make that deadline ;).....with you on it of course.
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This is on vft.org this morning.
Wow, my Shell OW72 has another brother right here in Oz. These bikes are rare enough in the USA but to have three of them here is pretty impressive. Not sure if it's an OW but it doesn't matter, Shells production based engines were nearly as good. It looks identical to mine except for the Morris mag wheel (although I have a pair)
(http://i1112.photobucket.com/albums/k495/firko2/firko2005/10Oct22-WantedYamahaParts_zps6699cac8.jpg) (http://s1112.photobucket.com/user/firko2/media/firko2005/10Oct22-WantedYamahaParts_zps6699cac8.jpg.html)
ENGINE PARTS for SHELL Yamaha 750. I have a Shell Yamaha 750 flat tracker here in Australia and I need engine parts including pistons, piston rings, gaskets, head gasket (85mm), cam, exhausts, Shell "slipper" piston kits. I am interested in any Shell items particularly NOS.
Please email tracey.farry@hotmail.com with what you have for sale, or know of where or who I can contact to source these items.