Numbers engraved into cases

[rpo83]

Hi Guys,

Do any of you have numbers like these on your cases?

I'm trying to figure out if they are a Yamaha or Bimota thing, i'm assuming Yamaha as it would be a pain to engrave them once in the frame!

[balky1]

Nope. I'd say these are post-factory engravings.

[Harvy]

I'm thinking journal bearing sizes/ids or something along those lines..... but its just a guess.

Harvy

[ribbert]

Hi Guys,

Do any of you have numbers like these on your cases?

I'm trying to figure out if they are a Yamaha or Bimota thing, i'm assuming Yamaha as it would be a pain to engrave them once in the frame!

I know nothing about Bimotas, did they do anything to the motors or just intall bog standard units?

Identical markings on two halves of something where they join is typical of workshop engravings (which would mean it's been apart in a professional environment), to make sure the critical bits remain a set or matched on the same motor. Engines these days are virtually blueprinted off the production line and mixing up components on a new engine probably wouldn't matter, not so much back in the 80's and 90's.

IMO

Noel

[Pat Conlon]

You can't mix and match upper and lower cases, so perhaps Bimota opened up the engine for some upgraded goodies (like shift forks)

[rpo83]

Thanks for all the comments guys, so what you are all telling me is that your bikes standard from the factory don't have these....

From what i believe, Bimota don't open the engines, they play with carbs/exhaust and on my other Bimota, an SB6 that uses the GSXR 1100 water cooled engine there are stories of different camshafts, but i think it may just be wishful thinking....

The bike has only done 9,200 k's from new, i might need to see if i can track down the original owner as he fitted the Ohlins rear shock, so maybe he played with the internals....

Thanks for all your help.

[aviationfred]

I am going to be inclined to agree with Harvy, Noel and Pat. A good source of information may be to locate a few motorcycle publications from back in late '87 and '88 that have a road test of the YB5. I am confident that if Bimoto opened the cases for upgrades, the magazines will mention what was done. Here in the US i would look at Cycle, Motorcyclist, Cycle World and Cycle Guide. EBay and Amazon are a good place to look for old magazines.


Fred

[Pat Conlon]

Last I checked, Bimota is still in business....

[rpo83]

I am going to be inclined to agree with Harvy, Noel and Pat. A good source of information may be to locate a few motorcycle publications from back in late '87 and '88 that have a road test of the YB5. I am confident that if Bimoto opened the cases for upgrades, the magazines will mention what was done. Here in the US i would look at Cycle, Motorcyclist, Cycle World and Cycle Guide. EBay and Amazon are a good place to look for old magazines.


Fred

Hi Fred,

I am a member of the Bimota Forum, probably the best resource for information, the issue with such a small bespoke manufacturer, is that anything is possible....

I have discovered there were only 5 YB5's imported into Australia, so i'm trying to contact the original guy who complianced  my bike to see if he remembers it...

[rpo83]

Last I checked, Bimota is still in business....

Hi Pat,

Although Bimota are still in business, it is a totally different company from the early days, Bimota have been bankrupt at least 3 times, and word on the street is they may be about to go under again.. There is no information to be found there..

http://www.cycleworld.com/bimota-motorcycles-status-historic-italian-brand

[racerrad8]

Those numbers are on all cases. As already mentioned, they are put there as a means of keeping the case halves together.

You can see them on a XJR 1250/1300 engine I am tearing down and the same numbers on my 93.

These number are not to be confused with the other number used to determine the crankshaft main bearing size calculations.

Randy - RPM

[rpo83]

Those numbers are on all cases. As already mentioned, they are put there as a means of keeping the case halves together.

You can see them on a XJR 1250/1300 engine I am tearing down and the same numbers on my 93.

These number are not to be confused with the other number used to determine the crankshaft main bearing size calculations.

Randy - RPM

Hi Randy,

Thanks very much, up to now the consensus from FJ owners was that these were not on their engines, so these numbers were post Yamaha, have you seen these numbers on 87 or 88 year engines, i assume you have seen many engines over the years....

Whilst i have your attention, could you give me your feedback on ignition systems, i will be rewiring my bike in the future so i'm wondering if i should chance my CDI.... I was thinking about a Dyna system, but i get totally contradictory opinions!! Some people love them, some hate them...

[racerrad8]

Those numbers are on all cases. As already mentioned, they are put there as a means of keeping the case halves together.

Randy - RPM

Hi Randy,

Thanks very much, up to now the consensus from FJ owners was that these were not on their engines, so these numbers were post Yamaha, have you seen these numbers on 87 or 88 year engines, i assume you have seen many engines over the years....

Whilst i have your attention, could you give me your feedback on ignition systems, i will be rewiring my bike in the future so i'm wondering if i should chance my CDI.... I was thinking about a Dyna system, but i get totally contradictory opinions!! Some people love them, some hate them...

Yes, many case have been trough my hands. All of them have that numbering system present. I will dig up some old cases and snap a photo of them too.

That is the crux of the Dyna system. When they work, they are great. When they don't you are stranded. Heat & vibration seem to be the biggest issue with the Dyna system.

Randy - RPM

[Pat Conlon]

How about what the Legends racers use....some magic red box...or something.

[Harvy]

Heat & vibration seem to be the biggest issue with the Dyna system.

Randy - RPM

Which is why mine is in the tail section of the bike (away from heat) and insulated from vibration by having the blue box stuffed into a stubby cooler.

Been running the Dyna system (ignition module, pickup and coils) for 6 years now with no problems whatsoever.


Harvy