Wilsons Sandbox

In a message dated 12/13/00 8:31:18 PM Pacific Standard Time, grandeal@... writes:

[i] [/i] Can anyone tell me if there is a kit to increase the 650 to a 750. I know There is a kit for the XR 650. Just wondered.

When doing my rebuild I checked every aftermarket supplier I could locate about oversize pistons for the KLR and found none. Kurt Grife

Surprising, with the number of KLR's out there, and their longevity. Maybe right about now would be the time for some folks to think about a top end rebuild and while you're at it bumping up the displacement. Any engine builders out there? Isn't one strategy to find a piston that fits one engine and bore the cylinder to fit? I know there's a lot more to it then just that, but through the years I seem to recall hearing about people fitting pistons from this car in that car, etc. The KLR engine is unique right, its not being used in any other vehicle? I wonder what's happening across the pond? Any of you international listers here of any hop up kits? Ed

--- In DSN_klr650@egroups.com, Krgrife@a... wrote: > In a message dated 12/13/00 8:31:18 PM Pacific Standard Time, > grandeal@h... writes: > > > > > > > > > > > > > > Can anyone tell me if there is a kit to increase the 650 to a 750. I > > > > When doing my rebuild I checked every aftermarket supplier I could locate > about oversize pistons for the KLR and found none. > Kurt Grife

Not to let the cat out of the bag--- I just got off the phone with a guy here in Northern Virgina who I am getting some spare parts from. He's got a 1995 KLR650 that he's converting to a racing bike. From what he told me during our short conversation he's done the following... 1) Removed the entire front end and replaced it with the front end of a GSX-R750. Had to have a new stem made cause the head tube on the KLR is so damn long. Cost him about $200 for the custom stem. 2) Removed original tank, putting on smaller custom jobbie. 3) Removed Uni-trak and relocated and remounted shock so it is a linear? rate setup. 4) Building an engine with 107mm pistons? (I am not sure if this makes sense... I really didn't catch all that he was saying) Custom cams, porting the whole nine yards. I will try and get pictures and more information this weekend when I get my parts if you all are interested. Let me know if you have any specific questions for him and I'll see what I can get out of him. Ride Safe, Zack SE DC 1991 KLR650 "Buster" 1986 Concours -----Original Message----- From: Ed Boyd [mailto:klxmoto@...] Sent: Thursday, December 14, 2000 2:40 PM To: DSN_klr650@egroups.com Subject: [DSN_klr650] Re: BIG BORE KIT FOR KLR? Surprising, with the number of KLR's out there, and their longevity. Maybe right about now would be the time for some folks to think about a top end rebuild and while you're at it bumping up the displacement. Any engine builders out there? Isn't one strategy to find a piston that fits one engine and bore the cylinder to fit? I know there's a lot more to it then just that, but through the years I seem to recall hearing about people fitting pistons from this car in that car, etc. The KLR engine is unique right, its not being used in any other vehicle? I wonder what's happening across the pond? Any of you international listers here of any hop up kits? Ed

--- In DSN_klr650@egroups.com, Krgrife@a... wrote: > In a message dated 12/13/00 8:31:18 PM Pacific Standard Time, > grandeal@h... writes: > > > > > > > > > > > > > > Can anyone tell me if there is a kit to increase the 650 to a 750. I > > > > When doing my rebuild I checked every aftermarket supplier I could locate > about oversize pistons for the KLR and found none. > Kurt Grife Visit the KLR650 archives at http://www.listquest.com/lq/search.html?ln=klr650 Support Dual Sport News... dsneditor@... Let's keep this list SPAM free! Visit our site at http://www.egroups.com/group/DSN_klr650 To unsubscribe from this group, send an email to: DSN_klr650-unsubscribe@egroups.com

I believe if you check the old archives, there was a guy who rebuilt his and used a Buick piston? Hey here it is!! http://www.listquest.com/lq/view.cgi?ln=klr650&mid=14689&sp=&q=buick&b=1&s=1 &o=0 CA Stu

Ed Boyd sez;

> Maybe right about now would be the time for some folks to think about > a top end rebuild and while you're at it bumping up the displacement. >.............................................Isn't one strategy to find a

piston

> that fits one engine and bore the cylinder to fit? ..............

Yes, but it ain't that simple. You can't get just ANY slug from just ANY source and hope that it works, just because it's the correct diameter. A head rebuild, however, might be just the ticket if you were to go this route. First issue to consider is the compression ratio that you want. This is achieved through a combination of head chamber design (thus the head rebuild), valve timing (again with the head rebuild), piston crown, squish area, piston throw (rod length and crank design), and medley of other considerations. Second issue would be the weight of the new pistons. They, along with the rings, wrist pins, pin keepers, rods, bushings/bearings and crank would need to be balanced out so as not to have a self destructing engine. Third issue is how to make this new "bigger pump" push the kind of air it needs to in order to work effectively. This, again, calls for the head to be worked using bigger valves, with cams that provide longer duration and possibly more lift as well. Then you get into the flow characteristics of the airbox, filter, carb, manifold, head work (again), header and pipe (Anyone out there running 12+ rings on a 'Trapp Race pipe?.... Again, this is dependant on the piston crown design as you could get away with the stock head specs it you found the right dished, as opposed to domed, piston. Then this would also have an impact on the aforementioned compression. See? You guys go and get me all fired up now.....(:^) In short, Yes. It can be, and has been, done. But it's not just a matter of reboring the cylinder and inserting a new slug. The simple "swap the pistons" route could be achieved if someone (possibly Wesco or the like) designed, manufactured, and marketed the proper piston with the proper crown. This is what you have when you talk the XR, Harley, Superbike, kits. It's real easy to get a kit and drop it in. It's another story all together if you're the one designing that kit. cheers Joe Nassif SFNM A13

>Surprising, with the number of KLR's out there, and their longevity. >Maybe right about now would be the time for some folks to think about >a top end rebuild and while you're at it bumping up the displacement. >Any engine builders out there? Isn't one strategy to find a piston >that fits one engine and bore the cylinder to fit? I know there's a >lot more to it then just that, but through the years I seem to recall >hearing about people fitting pistons from this car in that car, etc. >The KLR engine is unique right, its not being used in any othervehicle? >I wonder what's happening across the pond? Any of you international >listers here of any hop up kits? >Ed

My friend has rebuilt a KLR600 to a 650, a honda XL600 to a 650 and a KTM 610 to a 660. Power and low end increased. He said he'll rebuild my A2 when time comes (so far -80000km- everything's fine). From what he told me it's not just changing the piston. He worked the cylinder to a bigger bore, piston, but also cams, lines, lowered the head for 5mm to get more compression, changed the crankshaft and bearings and a lot more I dont remember now. The ccm could go to 675 and 700 but not over that. I am planning to do a complete rebuild of my klr at 100000km (probably spring 2002) and then I'll write the results and observations. But if I increase power I'll also need to change the front fork (dual discs) to stop. Now that would definitely cost much unless I find a good used one... Take care and ride well, Deks, Croatia _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

Zachariah Mully wrote: [parts suppliers with big plans]

> 4) Building an engine with 107mm pistons? (I am not sure if this makes > sense... I really didn't catch all that he was saying) Custom cams, porting > the whole nine yards.

[...] Sounds like lot of expensive work to happen. My guess is that a 107mm piston is possible as long as the block is bored out to take a custom made wet-sleeve. Then a custom head gasket might come in handy as well. For all the effort and expense trying to make a KLR perform, it may well be a lot simpler to adapt a new XR650 for racing. Mister_T

* Deks* wrote: [...]

> My friend has rebuilt a KLR600 to a 650,

[...] I have toyed with the idea of fitting a KLR650 piston into my KLR600 to get the engine capacity to an actual 600cc instead of the stock 564cc. I could probably get away with boring the stock wet-sleeve as the 650 bore was a 2mm larger radius, but even then the sleeve thickness may become an issue with excess flex and blowby a possibility. I figure that if I want 650cc then it would be easier to modify the frame to take a complete KLR650 power unit. Mister_T

>I have toyed with the idea of fitting a KLR650 piston into my KLR600 >to get the engine capacity to an actual 600cc instead of the stock >564cc. >I could probably get away with boring the stock wet-sleeve as the >650 bore was a 2mm larger radius, but even then the sleeve thickness >may become an issue with excess flex and blowby a possibility. >I figure that if I want 650cc then it would be easier to modify the >frame to take a complete KLR650 power unit. >Mister_T

He had to go that much cause the cylinder was damaged (inside) and it was the only way to save the engine from junk. Still, it melted due to overheating a few thousand kms later. The rider "killed" it making high rpms even though my friend told him not to go that high. On the other hand, the XL made another 40000km and the KTM is still running. Deks _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com