After a snippit of info.

[Anonymous]

Hello, firstly, after a dimension from a motor, I asked in tech info but no response at all. Putting it in here cheekily because Its performance related.
Can anyone measure (to the nearest couple of mm since Ill run a tensioner anyway) the distance between the shaft centres on the crank and starter motor shafts if they have a 750 2valver with the alternator cover off at some point? And also if I may be so bold the diameter of the starter idler gear at its maximum diameter?
Im trying to replace my current hyvo chain driven supercharger setup with a belt one because it seems a more intelligent way of doing things and gets round a load of oil sealing problems its been giving me, but Im on the wrong continent to measure up the distances etc. When I get back to the workshop, there isnt any belt supplier places I can nip into and buy the kit so it'd be good to get it all sorted while I can.

Also does anyone know of a supplier who supplies the flat isolator inner plates that drag bikes have in place of the alternator cover again on a 750 2 valve motor, and if so what sort of thickness and price they are? Or has anyone any good idea what the minimum thickness alloy plate I can use to stop the oil falling out the crankcases and run the sidecase dry?

TIA
Phil

[robinjo]

Sorry that I can't help you, sold mine a couple of years ago, i remember seeing the original question too, maybe someone can check it for you now. Supercharger Now I'm curious...can you tell us some more about your project? do you have a website maybe? Good luck on your project!

[Anonymous]

website

Sorry nothing current to show you and away from my toys to be able to take any photos etc.
Bike has a toyota sc12 blower behind the motor where the airbox would live on a n/a bike and uses fi and a megasquirt for injection.
Current drive is by a hyvo chain (primary chain from a gpz750a) up to a idler shaft where the starter used to live, and a gates belt drive to the blower thereon. Ill take some pics if I ever finish it to my satisfaction

[Paul]

You can buy the blanking plates to fit where the alternator cover used to be, Kosman is one name that springs to mind, Orient Express used to do them as well. But you pay a lot because it is a "Kosman" part!
Why not make one yourself? Just get a piece of alloy plate about 8mm thick, put your alternator cover on top carefully draw around it, then cut it out. Clamp the cover back onto plate and drill through the holes. Measure where the crank is in relation to the fixing holes, & drill a clearance hole through the plate. Then make a seal holder, mount the blanking plate on engine, push the seal holder onto crank nose & drill through the seal holder into the blanking plate to mount the holder. It sounds more complicated than it is, But it's an awful lot cheaper! I've made a few for my own bikes originally, then for mates bikes.
On your engine you could continue the plate up to mount the supercharger?
I don't have the dimension you need, but don't forget to fit some sort of tensioner to the belt - they stretch!

[Paul]

Where are you?
You say you are on the wrong continent to take measurements.

[Anonymous]

Plates

Cheers for the plate thickness, nothing like a bit of from the horses mouth to decide things like that. Ill get some 8mm alloy sourced up, my only concern was the minimum thickness as I had visions of it warping and distorting away from the gasket surfaces since it didnt have any shape to keep the stiffness and ribbing it would have meant needing more space between the belt and crankcase webs to clear,
plus the only ones ive ever seen were huge 30mm ones carved from a billet of alloy(I suspect they were also to stiffen the crankcase) on drag bikes, and that would have made the drive unacceptably wide for my application. Not worried about blower mountings since the blower already mounts on the rear engine plates and two lugs on the frame, and I *really* dont want to go through moving all that lot again....

Currently Im in Leeds, england for my sins for work (for another 6 months which sucks but a mans gotta eat and pay for bits), but my bikes are parked at two locations on mainland europe..