Bimota Forum

[Pompey]

If only we knew where all those old race bikes went... It took me years to get the 851 I wanted. Pure luck. That yb4 is a great example of the perfect find. Nothing more gratifying then making an old bag back to it's former glory. Shame the wife hates operations..
_________________
Pomps
Bimota's Db2, Db5 ,Ducati's 851' 92, 888' 93, Honda blade' 93, Triumph speed triple' 07, kawasaki zxr 750 k1

[Pompey]

Just got back home now crankcase, so pics of blade coming soon. Going to ride it up to meet a few of the guys on boxing day hopefully.
_________________
Pomps
Bimota's Db2, Db5 ,Ducati's 851' 92, 888' 93, Honda blade' 93, Triumph speed triple' 07, kawasaki zxr 750 k1

[oily]

[Pompey]

Is em riding across? Forecast is very good, be good to catch up before I work away for 7 months !
_________________
Pomps
Bimota's Db2, Db5 ,Ducati's 851' 92, 888' 93, Honda blade' 93, Triumph speed triple' 07, kawasaki zxr 750 k1

[oily]

hopefully........
but you know what women are like, she'll make the decision whilst I'm waiting to leave

Are you sure the place is open on the 26th?

[crankcase]

[crankcase]

Reply to who . . . . .

It came with a factory kit pre-production frame (Michael Doohan's 1988 2x WSBK oran park winning bike) Which was also Yamaha's first WSBK wins. Another project and a lucky find!

. wow, that's real history. Mick Doohans bottom has certainly not been anywhere near any of my bikes.

Directly behind it (shed photo other post? lol) is a TZ250T... Still has the original 1988 slicks fitted. Over to the side is an OW01. Not a Bimota in sight... lol.

. just getting you going

In relation to your YB, I'm of the understanding that in the early days Bimota bought the complete bike and then used all of the relevant parts, discarding the left overs. (later a deal was done and only components were purchase) The 88 Fzr (first delta box chassis) is yamaha borrowing conceptually from Bimota.

. not sure about that myself. But I did read that Y used some of the new thinking in their later FZRs, such as tilting the engine back a bit.

So on that premise you would expect that engine, loom, rad, fan. instruments, switch gear, and probably some other stuff is Yamaha. The YB4's should have the 1988 FZ750 engine fitted (2mg prefix) which is the Japanese market silver cased FZ750. (the silver cased black motors are substantially different to the gold cased motors)

. Yes, mine is silver cased and the homologation papers mention 2MG as the base.

I've been led to believe the fuel injection ecu is the same as Ducati 851, with a different chip fitted. I was under the belief that the injection circuit is essentially separate to the main wiring loom, but are happy to stand corrected on that one, or any of this...lol.

. I opened up both ECUs a couple of weeks ago- look exactly the same except for chip labels. My 851 also has 4 injectors too. It seems to be that the injector looms are quite separate. But according to the parts books and what I've seen in photos etc. is that Bimota made a 'complete' wiring loom for the YB4 including lights etc. But it's probably a case of wrapping the 2 looms together with tape. Which is pretty much how the 851 loom looks.
Aparantly all IWE (or whatever they're called) ECUs are the same, so we can use Ford Cosworth, Lancia Integrale, Ferrari F40 and a few other ECUs just with a chip change.

The FZR750 and the FZ750 radiators are very similar, but not the same. The lower fan mounting point on the FZ750 is central, where the 88 FZR750 are 2x off to the sides. I don't have any Bimota literature, parts or service, but I do have all of Yamaha's, both road and production racers... so if you need pictures of any Yamaha or part numbers just ask!

. The YB4 rad is definitely not a Yamaha part- looks quite different and has specific mountings for the Bim frame.

I also have a very good knowledge of parts interchangeability motor wise. All of the series look pretty much the same from 86- thunderace, but there are many traps... and cheats!

. So long as mine works, I'm happy, pretty sure it's stock. Previous owner was using it on the road too.

The body work on your YB4 Ian, Looks like it was never painted, or after market? Any idea where it came from?... Can we track down those moulds??? Also the white race-bike pictured... Any more photo's??

. it was definitely painted and quite often, there are 6 or 8 layers. I wondered if my bike had been raced, but I think there would have be more modifications to other parts (like Rubattos bike, which is totally modified).
There are people who can supply YB4 bodies, I'll have a look . . .

Sorry about the long winded post.
Cheers![/quote]

. nice to have a chat!

pictures:








sorry, those are all I took. Peter Rubatto was racing in the German superbike series of the day, here's a PR postcard that recently sold on ebay- not to me.



all the best
thanks for your interest and 'til soon
Ian
_________________
Bimota DB2 tricolore, Bimota YB4e.i, Ducati 851 tricolore, Ducati Hailwood Replica, 1968 Gitan Grillo sport, Yamaha GTS1000, Honda Deauville, Honda GB500 Clubman
http://thecrankcase.com

[oily]

[crankcase]

we were going to come over at Christmas last year, but after an hours drive in the snow back from Brigittes parents on christmas eve (20km) we calculated that it would take 3 weeks to get to Bromsgrove and back.
have a good one!
Ian
_________________
Bimota DB2 tricolore, Bimota YB4e.i, Ducati 851 tricolore, Ducati Hailwood Replica, 1968 Gitan Grillo sport, Yamaha GTS1000, Honda Deauville, Honda GB500 Clubman
http://thecrankcase.com

[crankcase]

The body work on your YB4 Ian, Looks like it was never painted, or after market? Any idea where it came from?... Can we track down those moulds??? [/quote]

here's a supplier in Germany http://presserundkuhn.de/html/yamaha_bimota.html

fairing: 849 euro
monocoque: 799 euro
hugger: 69 euros

not too cheap.

or there's this forum member (Jiří Válka) who posted a few days ago:
Hi, I have for sale
set bodywork Bimota YB4-6-8,fiberglass.front part of the three-part,rear original.Bodywork is original or racing version-without headlight.photo by mail.price 500 Euro.mail- bimota.fan@seznam.cz

fibreglass does occassionally come up on ebay as well. But it's usually damaged or tatty.
_________________
Bimota DB2 tricolore, Bimota YB4e.i, Ducati 851 tricolore, Ducati Hailwood Replica, 1968 Gitan Grillo sport, Yamaha GTS1000, Honda Deauville, Honda GB500 Clubman
http://thecrankcase.com

[who]

Thanks for the heads up on both of the leads It's good to know it is available even if a bit pricey. I have sent off an email to Jiří Válka. Cheers!

[crankcase]

Not a lot of time for the YB4 recently, but as we cleared out the living room in preparation for it's conversion into future kitchen, a bit of heated space is available 'til we get on with that.
During the clean up, I found another 'Bimota' box with 3 original style footrests, spare pedal, new number plate light, the steering damper, rear lights and loads of other bits that I couldn't find before- so well happy.

Then on Friday I noticed the coolant in the Ducati was freezing outside- better to get it indoors to warm up and change it.
So I might as well bring the YB4 in at the same time in case I find some time to do something there.

Brigitte was out for a couple of hours, but there again it's not the first time the Duke has been in here.

first job: screw my new air temp sensor in the airbox, the 'carb conversion' didn't need it so it has gone missing.


a very satisfying start


and strip the airbox, I have a new filter already to fit.


reconned Volkswagen Vento Bosch 'orange' injectors are same spec as the 'red' webers, which were very cheap and I didn't look for somebody to recon the 'reds' yet. They fit the YB4 even if the bodies are different because they get clamped between the fuel feed rail and the manifolds.

left are the original weber injectors, right are the Bosch

here's the fuel rail with the fuel regulator

I will also now be able to use the reds as spares for the 851 because 2 of the injectors on that are 'blacks', surely not good to mix injectors.

carbs on


carbs off and injectors in

they are underneath, squirting up stream.


I need to make 2 metal straps to hold it all together as original.


and the rail was a pig to get in

tight as a quite tight thing, above the coolant cross over pipe, below the cam chain tensioner and under the cam oil feeds.

throttle bodies on


first time full throttle! and now I know why there's another (longer) cable in the spares box.

and I still need the choke cam which fits on the right side end of the throttle spindle, will probably have to make one!

next job, camshaft pulse sensor

beautifully butchered

to be replaced, spare:


and crank sensor needs a new plug to fit the YB8i.e. wiring loom connector


here's the new YB8i.e. injection loom with ignition boxes and relays fitted


and a little ray of sunshine on this magical day


all under the watchful eye of Hamlet, or whoever it's meant to be


This is all a dry run to make sure everything fits and to find what else has to be done. I'm planning to strip the bike completely to clean and grease etc. before a final build and then getting it to run, which wil depend on how 'right' I do it all.
Haven't even touched the Duke yet, better get that out of the way first. When I get the 4 red Weber injectors cleaned- they'll be swopped over and a fresh (standard spec) chip fitted because there's an aftermarket chip in there and who knows what that's set up for. I'll order 2 for standard pipes and for the 'kit' megas.
Plus I need another fuel pump because the Duke pump conked out just as I finished checking the timing last month- put the YB4 pump in, not expecting a lot because it's been lying around 'dry' for the last 5 years or so- cracked straight up!

But I prefer to have the YB4 pump back in the Bim and get a replacement for the 851.

So I suppose that's all next
_________________
Bimota DB2 tricolore, Bimota YB4e.i, Ducati 851 tricolore, Ducati Hailwood Replica, 1968 Gitan Grillo sport, Yamaha GTS1000, Honda Deauville, Honda GB500 Clubman
http://thecrankcase.com

[crankcase]

forgot this

http://www.schottenring.de/Bilder_GP/Bilder-2011/original/Rubatto%20Wheelie.html

Peter Rubatto wheeling at Schotten last year, photo by Mike Riedner on the Schottenring website.
_________________
Bimota DB2 tricolore, Bimota YB4e.i, Ducati 851 tricolore, Ducati Hailwood Replica, 1968 Gitan Grillo sport, Yamaha GTS1000, Honda Deauville, Honda GB500 Clubman
http://thecrankcase.com

[oily]

Excellent Ian, Keep the momentum going
_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[who]

Looking good! Thanks for the tip regarding the Volkswagen Vento Bosch 'orange' injectors. Excellent!