650L carb opinions wanted

Just want opinions from people who have done the carb mods by Dave and Briain (shim needle, drill slide, and re jet) on their 650L's. How MUCH better is it now? How MUCH was your gas mileage affected? Is the LONGEVITY and RELIABILITY of the bike affected? Was running temperature affected? Is there much difference in power? Overall, was it worth it? Just interesed to see what people think. Also does anyone know where to find Honda OEM parts online.

I did the dj kit. And i am very happy with the results. As for longgevity,the motor should run cooler, now that its not running lean.

Dont know what a stock L gets for mileage but mine gets 33 mpg with all of this done. Full White Brothers exhaust also. I was thinking about playing with jets to get better mileage. The bike starts so much easier now. No choke on warm days and cold days with a little choke is all it takes. Im pretty happy with the mods. Just wish I got 40 mpg out of it. Oh well, my BMW Dakar gets 60+ so guess I will leave the L for dirt and not commute that much. As far as Longevity, I would think this would depend on oil changes and not carb mods. Although the Stock L is very lean, so any improvement in that department has to help keep the thing cooler and thus last longer. I also seem to have all but lost the off Idle stummble. Throttle response is much better than stock set up.


94 L

I noticed a difference on mine. Better response etc... The bike is lean factory and jetting it correctly will allow it to run cooler and should increase overall life. As a rule lean will make power to a point but will also really cause heat which will rob power.

If you were running 1/4 mile I would say lean but real world it's better to be a little rich than lean.

Gas milage :) Don't know don't care. All I worry about is range.

If you want to check it out I am in So. Cal. (N. Rialto) PM me.

OEM parts - I have heard Service Honda but have not used them.

I desmogged, air filtered, drilled the slide, shimmmed, and removed the baffle at the same time and noticed a BIG difference from off idle through mid range. Although it did pop like crazy on decelaration (way lean.) I then rejetted and butchered the exhaust a few days later and it seemed to have killed a little of the grunt. The XR flat spot off idle is still gone though :)

I found while some of the low end torque seems to have fallen off, the mid range and top end is incredible compared to stock.

I think what I'll do next is go 14/48 on the sprockets to make the mid range more useful on the trails. I ride in NorCal so I need useable power in the low through midrange. No deserts for me...

All considered, I'd definately do it again :D

With the riding I do, crawling through the woods, rockfields, edges of high cliffs, hillclimbing, etc. the real gain in the mods for me was controllability and predictability.

There's nothing like having almost no place to put your feet down while crawling up a rocky ledge, and having the engine pop or stall because you're only just above idle.

Oh yeah, the wheelies are much better too!


I get in the 44 mpg range on the road, 15/48; 35 mpg or so in the dirt, 14/48.

De-smogged, carb mods, (55/160, slide drilled, .040" shim under needle), stock exhaust, de-baffled. I know I'm a little rich, but I was getting some knock at full throttle and that took care of it.

Yes, definately worth it, runs cooler no hesitations and no backfiring even with my white bros. e-series. I'm way over geared with stock gearing and the terrorflex on the rear. I do alot of higher speed gravel road riding to work ( 75-80mph) so I'm 3/4-full throttle most of the way. My temp runs 250 on the upper end on hotter days and about 195 on the cool mornings (30degrees). It never would run that cool with stock jetting. Mileage is about 30-35 mpg depending on how hard the wind blows, head or tail wind. I just did a rain ride this weekend however and got 45mpg at about 60mph all on pavement, so it really makes a difference with speed and nice road conditions on my bike anyway. Hope this helps.

The best carb. mod. you could make would be to install a Edelbrock carb.... :)

Some of us are too darn cheap!


did the mods, got a very slight flat spot off idle. i can live with it. some people might not even notice it. I tell you that doing the mods is a must!!! way funner now, mid range to upper midrange is like night and day difference. stock gearing and can wheelie in second gear like you wont believe!!!

Is your flat spot when your are rolling throttle on slowly or even holding steady throttle just off idle? if so warm up your bike than with it on a stand slowly bring your rpm`s up to to the flat spot and hold the rpm`s their then reach down and adjust air mixture screw inward until flat spot is gone. just something that you might be worth trying.

I have done the mods on my 94' L. drilled slide, shimmed needle, rejetted, desnorkled FMF Q pipe, K&N filter and many others. The carb stuff I noticed the throttle bog on hard acceleration is gone, the rpm ramp up is more constant and makes the power up more managable. The engine runs noticable cooler than stock just by the feel on your legs( at least 10 deg). The Q pipe smoothed out the power band. It would pull hard then fall off a just a little in the mid, Then taper off from there in the top end, with the stock pipe. Now it pulls smooth and consistant all the way through the top end.

I had run a Mikuni slide carb for a while. Though it made a little more top end power it suffered badly in the drivabality department. Thats when I went back to the stock with mods. I do forsee replacing it.


Check Bikebandit.com for online parts info.

As far as the stock carb goes, once you figure out the jetting and do the requisite (carb) mods, you'll be good to go in almost any condition. I've ridden from sea level to over 4,500' in elevation with no driveability problems. The bike runs how it's designed instead of being choked off for emissions.

The rule of thumb for jetting is that it's better to be richer (I wish) than leaner, especially for WOT riding.

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