Suzuki GT 750 - question about gear

[expercat]

Suzuki GT 750: question about gear
I am rebuilding a Suzuki Gt 750 engine by parts coming from different engines.
However I am sure the upper and lower crankcase coupling is correct.
The colour paint daub mark on lower crankcase has gone lost.
So I have to discover which measure identify the original crankcase colour and after I'll be able to have a correct matching between input shaft, output shaft and kick starter shaft.
Suzuki Factory gives 2 colour class for identifying engine crankcase dimension.
First group has brown, black, red and yellow engine cases.
Second group has blue, green and white engine cases.
On "first group" engine cases I have to use for first gear, second gear and kickstart gear yellow –yellow – brown gears, on "second group" engine cases I have to use for first gear, second gear and kickstart gear white – white – yellow gears.
I read these instructions on Suzuki GT 750 workshop manual.
Maybe I am too over-careful but I want to be sure to make a good job.
If I’d know which measure identify crankcase construction for first engine group (brown, black, red and yellow) and for second engine group (blue, green and white) or where I have to take this measure on lower crankcase (I presume) my job would be much facilitated.
I don’t find these data on workshop manuals.
Thanks for help.
Mike

[oldjapanesebikes]

That's not easy to answer - the only real spec is the allowable lash on page 40 of the shop manual. I practice I've noticed that the paint markings were not on the early cases (you don't mention what model you are putting together) and in addition to lash tolerances there are also changes to the number of teeth.

Take a look at service bulletin 3 and 29. The manual and service bulletins can be found at this link.

http://www.oldjapanesebikes.com/mraxl_G ... index.html" onclick="window.open(this.href);return false;

[expercat]

Hi Ian!
first of all thanks for your suggests.
I am a new Sundial Moto Sports member and I appreciated your "welcome" very much.
Now I am reading all the Suzuki technical bulletin.
I am working on 2 Suzuki GT 750 engines.
First engine has 69122 number. This engine has only 7.500 km and all the parts are in very good condition except the crankshaft where an oil seal was badly damaged. So the crankshaft was rebuilt in Germany.
The lower crankcase has a red paint mark so I am sure the first driven gear is yellow, second driven gear is yellow and kickstart gear is brown. The gears backlash is correct and I measured gears coupling according Suzuki GT 750 workshop manual pag. 40.
Now I built, using a lathe, 2 false aluminium "bearings" with same sizes of original gearbox bearings on engine right side (imput shaft 62 mm diam. and output shaft 47 mm diam.) Then I drilled these "bearings" and I refinished these holes by a 10.00 great precision reamer.
So, using a digital caliper, I'll read the distance between the imput shaft center and output shaft center (5.00 +X+5.00).
By a similar method I'll find the distance between output shaft center and kickstart shaft.
In my opinion, this procedure can be a first step for investigating about Suzuki GT 750 crankcase class dimension.
Then I bought on eBay USA a white first driven gear. This item has not still arrived to my address.
When this item arrives I 'll be able to understand which is the difference between yellow and white gear dimensions.
The other engine, (without paint mark) which I am rebulding using parts coming from different sources, is 36610.
It's a working in progress.
What do you say?
Regards.
Mike
P.S I apologize for my English. I am trying to improve it.