Identifying mods

So when you buy a used bike, you are getting a "pig in a poke". No problem - start it up, sounds good, here's my cash. If everything appears to be stock, then planning upgrades is fairly straightforward - buy some parts, do the build.

However, everything is not stock. The PO, a squid with a new R6, had the bike for about a year. Told me the PPO had done a bunch of work to it, "top end, wiseco stuff, it's like a 750". Fair enough. I can see the oil cooler, I can see the electronic ignition, I can see the air shocks.

I can't see what's inside, and even if I could, this is my first project and I'm not sure I would be able to tell what I've got anyways. So my question is, what mods would someone have done to make my 650 "like a 750", and how could I identify those, either as is or after I get it apart? Planning to upgrade carbs is not too bad, because I can tell those are stock, but I can't hunt for deals on anything else if I suspect I may already have it.

i missed this. check pm about carbs:P

77KZ650 wrote:

i missed this. check pm about carbs:P

Got it - thanks.

You can check the block stamping to see if it's stock or has a 750 block. The 650s will have 652cc cast into them on the front under exhaust #2 (If I remember correctly). A 750 block will have 738cc cast in.
If it's a 650 block that has been rebored to a 750 or other CC, then you'd have to disassemble the engine and measure the bores.

Can't really tell without having some parts off the bike. You can measure the cams to see if they are stock. You will need the head off to see if the pistons are stock or if they have been bored. Carbs may be stock but they could have a jet kit installed.

rstnick wrote:

You can check the block stamping to see if it's stock or has a 750 block. The 650s will have 652cc cast into them on the front under exhaust #2 (If I remember correctly). A 750 block will have 738cc cast in.
If it's a 650 block that has been rebored to a 750 or other CC, then you'd have to disassemble the engine and measure the bores.

Thanks, Rob. 77KZ650 covered a lot of this with me over PMs, but I appreciate you adding it here.

Using the above info, mine is a 650 block. From what Scott tells me, Wiseco made two kits for the 650 - a 700 and a 720. They no longer sell the 720, but I'm pretty sure my mods were done some time ago, so the 720 kit would definitely have been available, and is likely what would have been used, given how the rest of the bike is done (trying to see insidet the PPO's mind here).

My carbs are definitely stock - it may be worth looking into an upgrade there given the big bore and the 4-1 exhaust are already in place.

Is there anything else that might have been done, or potentially could be done? Cams, etc?

Post edited by: DrWhizBang, at: 2007/05/15 15:44

kawtoy wrote:

Can't really tell without having some parts off the bike.

True enough. I need to know what parts to take off

You can measure the cams to see if they are stock.

That sounds like a good idea - I only need to know what cams I might find, and how I would recognize them.

You will need the head off to see if the pistons are stock or if they have been bored.

The PO says they are Wiseco, so I figure that's correct. His information at this point has been accurate, if not precise

Carbs may be stock but they could have a jet kit installed.

I assume if they were not jetted it would not be running smooth with the 4-into-1 and Yosh pipe. As it is it runs great. They are definitely the 24mm bodies though.

Keep in mind that it also possible that 750 sleeves were used in a 650 block.

I suspect there are a lot more KZ's running around with claimed Wiseco kits, than there are KZ's that actually have them.

Do a compression check, if the compression is over 170 then something has probably been installed