YZF 750 gearbox....

Post by **Max** » Thu Nov 02, 2006 1:03 am

It looks like the main cases and cylinders are off the 900, the head, sump and assorted side covers off the 850. Also, the ratios of the 900 are different from the YZF from memory.

Post by **phuk72** » Thu Nov 02, 2006 10:07 am

Over got the YZF 750 as i thought.....

http://www.motorcycle.com/mo/mctext/over.html

It may have started life as a YZF750 box but it was completely re-engineered by Over to the point that, if they had put it into production, they could have legally branded it an Over item.

Think of it as being as close to the YZF750 box as the road going R1 is to what Haga rides

Killerwhale · Post by **Killerwhale** » Thu Nov 02, 2006 11:27 am

phuk72 wrote:
Over got the YZF 750 as i thought.....

http://www.motorcycle.com/mo/mctext/over.html
It may have started life as a YZF750 box but it was completely re-engineered by Over to the point that, if they had put it into production, they could have legally branded it an Over item.

Think of it as being as close to the YZF750 box as the road going R1 is to what Haga rides

I get the drift, damn i want something that works both in slow traffic and fast runs on a summer night...
I guess iÃƒâ€šÃ‚Â´ll go back to the original gearing and change frictiondiscs once a year!

Post by **phuk72** » Thu Nov 02, 2006 11:56 am

damn i want something that works both in slow traffic and fast runs on a summer night...
I guess iÃƒâ€šÃ‚Â´ll go back to the original gearing and change frictiondiscs once a year!

I use 17 / 42 gearing and have no problems in town or on fast runs

Killerwhale · Post by **Killerwhale** » Thu Nov 02, 2006 12:01 pm

phuk72 wrote:
damn i want something that works both in slow traffic and fast runs on a summer night...
I guess iÃƒâ€šÃ‚Â´ll go back to the original gearing and change frictiondiscs once a year!
I use 17 / 42 gearing and have no problems in town or on fast runs

I use 16/39 and it revs like a motherphuker! Really nice in town though!

Post by **phuk72** » Thu Nov 02, 2006 12:15 pm

16/39 is fundamentally the same as 17/42 - that's good for over 140mph. Good enough for me!

Don't be concerned by the fact that the engine is revving - that's what it is designed to do.

burty · Post by **burty** » Thu Nov 02, 2006 2:10 pm

Another vote for 16/39 from here. Better low down IMHO (I do a lot of town work), although I changed the sprocket before sorting the engine and my engine is much much smoother at low revs than it was, so I wonder if a change back to 17 on the front might be tolerable now.

6000 revs is just over the 100mph, I rarely go much over that anyway. I've never had onto the rev limiter in top, although I'm confident it would get there.

Post by **phuk72** » Thu Nov 02, 2006 2:26 pm

I have had mine bouncing off the limiter in top (on unrestricted authobahns in Germany you understand

) and the clocks are reading just shy of 150. This incidentally is what the dyno reckons is the top speed as well.

Only once have I hit the limiter on the track (at Silverstone) - but that was just as I was reaching for the brakes anyway

earywig · Post by **earywig** » Thu Nov 02, 2006 2:29 pm

16/39 is the ratio that B&C Express recommended to me last week.

wicky · Post by **wicky** » Thu Nov 02, 2006 9:10 pm

Max wrote:It looks like the main cases and cylinders are off the 900, the head, sump and assorted side covers off the 850. Also, the ratios of the 900 are different from the YZF from memory.

gotta agree with Max on this one, apparently the 850 cams are a bit more lively than the soft tooned 900's. clever chap whoever he is

Huby · Post by **Huby** » Sun Dec 17, 2006 6:38 pm

Hello folks

i am just trying to fit an 6speed gearing from the YZF750 into my new Trac-engine...
The problems are: Everything fits fine in the Box...
But anything fits together in the Box..

You have to make new Transmisson Forks, the place where the clutch has to be fitted has to be cuttet, and so on...

I asket some GuyÃƒâ€šÃ‚Â´s in Japan, and i am still waiting for an answer.

By the way --- The Gearbox from the R6 make the same ProbÃƒâ€šÃ‚Â´s

Please excuse my Englisch