600R versus 650L power

I accept the fact that the 600R had more power than the the 650L because everyone says it's so. :crazy:

Why?

I know the 600R is lighter due to the lack of the starter, battery and additional bracing and other stuff (?) required to make the 650L street legal off the factory floor but mostly they are pretty darned similar

The 650L has lower compression but more cc's. Those extra cc's don't seem to be helping.

So considering that the engines are the same design what would it take to bring the XRL to the power/performance level of the 600R (besides losing weight)?

A number of things work against the 650L as compared to the trusty 600R. First and foremost, depending on what year 650L you have, it's got SMOG crap on it, the 600R never had to deal with that. The second thing is the cam, the cam in the 600R was much hotter than the 650L, more duration, more lift, etc. Lastly, the CDI on the 600R has much more aggressive mapping with regard to fuel/air mixtures than that of the 650L. So, that's what you've got against you if you own a 650L as compared to my 600R. The guy to talk to if you want to interchange parts is [rmhrc630] on here, he's got the only(that we know of) 600R in the world with E-Start. He's swapped CDI's and knows everything that's interchangeable between the two models and knows alot about the subtle differences between the two.

Yep thats pretty much it..

Smog pump is ugly and more weight but doesnt really rob power. Run a higher compression and add a cam and you will have more power than the 600r

Actually, the SMOG pump isn't suppose to rob power, but two things cause the pump to rob the eninge of ponies. First, the SMOG pump is actually an air injection pump, it pumps fresh air into the exhaust to help dilute the exhaust emissions, it takes air from the air box and injects it into the exhaust pipe. This means that, unless you've opened up your already restrictive airobx, the pump is robbing the engine of the valuable cubic feet of air it needs to breathe properly. Secondly, with the pump attached, it makes it very difficult to jet the bike properly because the pump changes the amount of air being fed to the engine so often. Trust me, take the pump off, get it jetted correctly and you'll notice a BIG difference.

...well actually the smog stuff "falls off" almost immediately after purchase on most of these things doesn't it? I'd forgotten all about it.

I've had both. I have to say for either bike, short of the obvious piston/cam enhancments it's all about intake, proper jetting, and the pipe.

I had a '95 650L with an unrestricted air filter, baja designs jetting kit, and a White Brothers Supertrapp Megaphone (8discs). That bike ripped it up as well as any 600 with the same mods. Just as much power or more.

Removing the smog crap and other weight is essential for any serious off road capability.

What the L has going for it is the extra 50cc's don't get the power back, but they get the torque!

That's why the L isn't 'fast', but it shrugs at terrain that makes some faster bikes whimper.

Those that have been 'in the rough' know just what I'm talkin' about...

Dave

I've owned both.

Both were uncorked and jetted setup well but not modded per say.

The previous posts have summed up pretty much the issues about the 600 having a more aggreive ignition curve, it hits hader and revs faster as well it has a lighter flywheel. This likely doesn't provide much more actual hp #'s but it sure does feel stronger and behave's stronger which is where it counts....at the rear wheel and at the rider's throttle hand.

The 650 being much heavier magnifies this as well.

My seat o pant meter always gave the impression of the 650l being torqueir off the bottom and the midrange but very lazy on the top end and when revving it out.

The 600r revved faster, hit harder in the upper midrange and revved out very well.

The bike was also much lighter which was always very noticeable, even when my 650l was lightened up significantly.

Just for comparison sake here is the 2 bikes setups:

90 600R opened airbox top, up 1 pilot size and 170 main with needle in the 4th clip and a stock muffler with an open end cap. 15/47 gearing

Plated and used for backroad blasting/occasional urban assualt.

02 650L snorkel out/smog stuff removed/DJ kit/Supertrap Q with 6 discs/15/47 gearing/.

( I tried the Dave's mods of 55/158 and shimmed needle to compare to the DJ setup and the power was the same but the dave's mods was criper throttle response, otherwise very similar)

I would have definitley gone to the high comp piston if I had kept the 650L as I'm sure it would have been an improvement.

At the end of the day I feel the 600R was a lighter/faster bike with a more fun power delivery, it would likely be perfect with a bigger bore and more compression.

I never had a prob kick starting the bike and always felt the electric start of the L was simply wasted weight/complexity but that's a personal opinion.

I have sold both and moved to a 650R now, in the process of setting it up for next year. Am actually uncorking the 650R literally as I type this!!HeHeHe!!

A number of things work against the 650L as compared to the trusty 600R. First and foremost, depending on what year 650L you have, it's got SMOG crap on it, the 600R never had to deal with that. The second thing is the cam, the cam in the 600R was much hotter than the 650L, more duration, more lift, etc. Lastly, the CDI on the 600R has much more aggressive mapping with regard to fuel/air mixtures than that of the 650L. So, that's what you've got against you if you own a 650L as compared to my 600R. The guy to talk to if you want to interchange parts is [rmhrc630] on here, he's got the only(that we know of) 600R in the world with E-Start. He's swapped CDI's and knows everything that's interchangeable between the two models and knows alot about the subtle differences between the two.

the cdi units from the 600 and 650 are not interchangeable. the 600 see's AC and the 650 sees DC.

with an inverter a 600 cdi could be adapted to the 650l.

the cdi units from the 600 and 650 are not interchangeable. the 600 see's AC and the 650 sees DC.

with an inverter a 600 cdi could be adapted to the 650l.

An inverter, that also doubled or trebled the frequency.

A straight 12VDC to 120VAC 60hz auto inverter was tested by a TT'er, and it only ran to 3000rpm or so.

Dave

An inverter, that also doubled or trebled the frequency.

A straight 12VDC to 120VAC 60hz auto inverter was tested by a TT'er, and it only ran to 3000rpm or so.

Dave

You could always bypass (kind of, maybe circumvent is a better term) the 650L's CDI inadequacies by installing an iKat, which modifies the ignition signature to a better, cleaner profile. :crazy:

Lastly, the CDI on the 600R has much more aggressive mapping with regard to fuel/air mixtures than that of the 650L. .

I'm always eager to learn, but I do not know how this can be true. The fuel/air mixtures in a carbureted motorcycle would seem to be independent of any electrical input. The CDI could easily control spark timing and limit revs, but I don't know how it would do anything else. I thought fuel mapping pertained to fuel injected bikes only.

I'm always eager to learn, but I do not know how this can be true. The fuel/air mixtures in a carbureted motorcycle would seem to be independent of any electrical input. The CDI could easily control spark timing and limit revs, but I don't know how it would do anything else. I thought fuel mapping pertained to fuel injected bikes only.

maybe he meant a more aggressive ignition timing advance curve. that is what i would think.

But that is not what he said — and I wanted to clarify that the cdi on a xr600r can not alter air/fuel ratios.

But that is not what he said — and I wanted to clarify that the cdi on a xr600r can not alter air/fuel ratios.
You're right, it cant.

correct. that is pretty much a given w/o F.I.

You could always bypass (kind of, maybe circumvent is a better term) the 650L's CDI inadequacies by installing an iKat, which modifies the ignition signature to a better, cleaner profile. :crazy:

If an Ikat does anything (I'm a skeptic), it will certainly not give you more advance.

Dave

I am in the process of experimenting with CDI's.

Speaking from experience, the 600 gains a lot of performance over the 650L due to its lighter flywheel. A good example of this is if you take the starter gear and clutch off the 650L. It makes a big difference to pick-up.

Im now running my 650L based 675 without any flywheel and it accelerates like a modern surpemoto. So much so it needed heavier clutch springs.

The downside is enormous engine braking!! Makes life interesting on the race track!

If an Ikat does anything (I'm a skeptic), it will certainly not give you more advance.

Dave

Well, according to their website it promises ....

* Modified spark, Superior Burn Technology

* Changes spark "shape" produces a "cooler" burn

* Allows the air/fuel mixture to be completely burned through

* Produces minimal emissions (zero under some circumstances)

* Dramatically increase power under load

* Improves throttle response

* Increased torque

* Improved fuel economy

I've got one, but never got the chance to install this summer. I plan on installing it this Winter and seeing if the promises are true next season.

my question is, how can a ign. box change the temp of a spark/burn?

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