....and talking about other manufacturers..just for Kev (as he's stuck on a desert island in the middle of nowhere), if you google Derbi Mulhacen 659, Kev (if you haven't seen it already),..sort of flatracker style...I like it (if you like that sort of thing..)

I did not know it snowed on a desert island, on my map Australia is in the middle & the UK is right on the edge of the world, heee.

Yes I have seen that before.

hehe...lol

I am very excited about getting this other engine, it means I can now approach the project in a more complete/comprehensive way.

What I was trying to do before, was to keep the short block uncracked. My engine is almost new, and it seemed the logical approach, as far as budget goes. But, not getting the rod-to piston balance was a downside.

Now, I can do a whole motor, but, the budget will increase.

I would like an uprated con-rod, so I can "up " the revs more safely, and get the crank-rod-piston balanced/lightened. I can also do a couple of other bits of fine tuning.

Its a growing project......just try to keep it within my realms of "sensible" (I haven't heard the two words together before...Richard and Sensible, sounds weird):deathmetal[1]:

Sounds like a better plan rebuilding the new motor & leaving the orginal one standard, that way you can sell the modded motor when you are finished playing.

Once you decide what mods you are finally doing we can talk, as you keep changing your mind as new ideas are put to you.



:darth:

yep...that's me......just been airing my thoughts on the forum!!

:sleep01:

..but my mind changed since I went for a chat/visit to the engine builders, re: still getting the pull/power low down with a big cam....and I think we can pull that one off, by experimenting.
Therefore, I will try some different cams.. long/short duration, different durations ........and lifts high..or not so high.
The 5050 will be a "Benchmark" cam, along with the standard cam of course.

Approve Kev?

Sort of changed my initial project ideas........haven't I??

Well the first part has arrived, all the way from America.

The wrong part! I clearly stated what i wanted on the heading of the order. donuts!!

grrrrrr.

Anway, for information, a Wiseco 103mm 11.5:1 Piston, with Pin and Clips = 506g.

I have found something!! I am going BIGGER BORE !!!
 

Since getting the wrong piston (! great thanks!) ..I had a look with the 103mm and the barrel.

I now think it is safely possible to go to a larger Big Bore......with the Standard XT660 Barrel/cylinder..

In this picture No.1, you can see the barrel, the correct way up, sitting on the engine, as it were.....with the Skirt on the bottom, that sits in the crankcase... it is this Skirt that is about 4mm. You can also see "inside" the Barrel, through this hole , the outside of the Skirt. This is much thicker than 4mm, its about 8.5mm. It is in this area the piston mainly moves, not in the Skirt.... http://i933.photobucket.com/albums/a...jpg?1283762821

In picture number 2 you can see the thickness of the Skirt, which is about 4mm....

http://i933.photobucket.com/albums/a...jpg?1283762962

In this picture No.3, you can see "inside" better... it definately thicker,its the inner wall of the water jacket...

http://i933.photobucket.com/albums/a...jpg?1283763040

And looking from the top, in picture No.4, you can see the inner wall of the water jacket , to the wall of the cylinder..its about 8.5mm

http://i933.photobucket.com/albums/a...jpg?1283763122


So, as long as the skirt is "meaty" enough...that would vary on differing opinions, you should be ok

So, how much do you leave on the skirt????

I am going to be maverick, and try a 104mm piston.(about 2mm left on skirt wall). I have a spare engine, and fast fingers " clutch-side" (but I don't think it will be the case), I think it should be ok with a 2mm Skirt wall......wait and see.....the 714cc Big Bore....

Brave man with a 2mm sleeve.

Can't see any photo's.

Why not fit one of these & go to 106mm.

http://cgi.ebay.com/ebaymotors/CYLINDER-SLEEVE-YAMAHA-06-07-RAPTOR-700-700R-YFM700R-_W0QQcmdZViewItemQQhashZitem20b212dc1fQQitemZ14042 6533919QQptZMotorcyclesQ5fPartsQ5fAccessories

Or if you have the funds.

http://cgi.ebay.com/ebaymotors/Yamaha-Raptor-700-Big-Bore-741cc-JE-Piston-106-Cylinder-_W0QQcmdZViewItemQQhashZitem4ceceb8961QQitemZ33039 2373601QQptZMotorsQ5fATVQ5fPartsQ5fAccessories

[quote=Kev;137822]Brave man with a 2mm sleeve.

I know Kev....don't !!!!!

2mm on the skirt it is.....its actually 2.5mm......

I have a whole spare engine to play with, AND an extra barrel.....