XR650L big bore reliability

lookin for a few more ponies.

This is what my 1997 XR650L supermoto has so far

Wiseco 10.25 piston

Hotcams stage one cam

Head ported and polished

Three angle valve job

Mikuni flat slide carb

Yoshimura can

Uni pod filter

was gonna get a Big Gun Evo to let her make some more use of the current engine mods, then I thought maybe big bore.

I just do twisties, track days and run errands around town. How much reliability will I lose with a big bore kit?.........suggestions for big bore kits as well

I'd have to say pretty damn good... I beat the snot out of mine everytime I get on it and not one problem yet, oh and its been 2k miles since the rebuild. Good luck!

Zack

YOSHIMURA right on!

the jetting guy here said for me to get a yosh full exhuast for my XR650L, but the thumpertalk stpre said they don't make one

any exhaust suggestions ?

which big bore kit zack

Full FMF made my L a totally different bike, a little loud but not bad..had the same effect on my R so I believe in the FMF products...better change the oil a lot with all you have done to the motor,as well as go to full synthetic oil

XRs only full comp.system in stainless,it wont fall apart.

thanks

It burned oil with Mobil 1, the guy before me ran Rotella and it doesn't use oil. plus its cheap!

so what big bore kit?

the jetting guy here said for me to get a yosh full exhuast for my XR650L, but the thumpertalk stpre said they don't make one

any exhaust suggestions ?

which big bore kit zack

yeah, yoshi discontinued it quite some time ago......you can get a slip on still i think....but that does her no justice....it was also like 600 bucks for a full system when they made it. you may be able to track one down still i dont know.....i see them on ebay once in a blue moon. some shop out in the middle of no where might still have one.....as a yoshimura owner, i must say, it KICKS ASS.....if u want a pipe that is louder and deeper than any other.

yeah, yoshi discontinued it quite some time ago......you can get a slip on still i think....but that does her no justice....it was also like 600 bucks for a full system when they made it. you may be able to track one down still i dont know.....i see them on ebay once in a blue moon. some shop out in the middle of no where might still have one.....as a yoshimura owner, i must say, it KICKS ASS.....if u want a pipe that is louder and deeper than any other.

any idea what the name of the system was........tri-oval etc.?

Just go with the 102.4mm wiseco 10.25:1 piston. Its like 165 and figure 45 or 50 for machining. Then base gasket and a new 102.4mm head gasket, you can use the valve cover gasket over, just use black RTV silicone. As for maintence, you might need to change the oil a little more often but not too much more. The larger bore doesnt make that much more heat to make you change your oil like a 450r. You dont need full synthetics either, although it wont hurt it, its not nessicary at all.

For exhaust, if I rode off road with the bike all the time I would leave the stock silencer on for noise but mine is on the road 100% of the time. My opinion is its a lot of money for little gains but if your more for the sound then thats cool too. Good luck, oh and contact thumper racing.net. They did the machine work on my bike and really recommend them!

Zack

Just go with the 102.4mm wiseco 10.25:1 piston. Its like 165 and figure 45 or 50 for machining. Then base gasket and a new 102.4mm head gasket, you can use the valve cover gasket over, just use black RTV silicone. As for maintence, you might need to change the oil a little more often but not too much more. The larger bore doesnt make that much more heat to make you change your oil like a 450r. You dont need full synthetics either, although it wont hurt it, its not nessicary at all.

For exhaust, if I rode off road with the bike all the time I would leave the stock silencer on for noise but mine is on the road 100% of the time. My opinion is its a lot of money for little gains but if your more for the sound then thats cool too. Good luck, oh and contact thumper racing.net. They did the machine work on my bike and really recommend them!

Zack

thanks zach

I already have the Wiseco 10:25:1 Piston, so the machining would be all I need and the gaskets ?

I have an oil cooler already as well.

Right now I have the stock headpipe and a Yosh RS-3 can off some sportbike. If a sull system is not going to make an HP difference then yeah I guess stick with what I have. I would think that an aftermakrte header would be less restrictive and realyy accentuate all my motor work, would it not? Sound makes no difference to me, I just want some more power to make climbing twisties in North GA better. Downhill I can run with or smoke the sportbikes but 10 more ponies would sure help in the uphill stuff.

I have never dyno'd the bike, but I would think it make maybe 40HP now.......can ya get in the 50+HP from an XR650L ?

Do the rest of the stokc internals hold up well with a big bore kit ?

Would you call 20,000 miles reliable? I think you have already done the biggest part, another 25cc's may not be as much extra as what you're looking for.

I'm the second owner, my bike has been a big bore after the first thousand miles, I did the 10.25 piston, cam, mikuni, and big gun around 12k.

I need to go find BWB's webpage with the dyno charts, nice piece of work!

About the big bore what kind of machining is done?

About the big bore what kind of machining is done?

Just bore the cylinder to match the new piston.

It may be a good idea to keep an eye on engine temps and possibly add an oil cooler.

any idea what the name of the system was........tri-oval etc.?

It wasn't a Tri-Oval; that seems to be a later(and currently used) name and design for Yoshi cans. I have a full Yoshimura exhaust on my 600 and while I can't compare it to stock(it came with the bike), I don't usually find myself running out of power, even on the low end.

If I had a TIG welder, I'd try duplicating my stepped header.

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