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XR-L - Dave's Carb Mods - Any Negatives?

23 posts in this topic

For those of you who have performed "Dave's Carb Mods" on your XR-L, have any of you had any problems at all related to them? I've done a good bit of searching and haven't read anything negative yet, but thought I'd ask - just in case.

I recently picked up a '93 XR650-L and have been reading all the glowing comments regarding "Dave's Carb Mods". The previous owner had put an old external disc Supertrapp pipe on there (currently with only 5 discs in) and says he rejetted for it - but I don't know what size jets are in there. The smog pump is already gone and the airbox snorkle removed, but the stock air filter was in there. I've replaced that with a Uni foam filter. Sounds like all that's left for me to do is drill the slide, shim the needle and check the jetting.

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No problems unless you count less fuel milage.But we new that before we performed the mods.

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Do em, you'll be surprised at the difference and the bike starts and runs way better.

Todd

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how does it perform with a stock exhaust?

i was going to do the Dave mods, desmog, desnorkel, and add a uni air filter but i want to keep my stock pipe for awhile! call me crazy, but i like the quietness. will i regret this?

anyone running like this?

thanks

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I helped a buddy do the mods to his 650L. He swaps out a fully stock exhaust and a WB E-series depending on sound requirements. Most will recommend a 58 pilot, shim the needle and 158/160/162 main depending on exhaust/airbox mods.

Here in FL, sea level, I've been having him run a 55 pilot, and we actually took the needle shim back out for extra gas mileage. Still runs good. With a stock pipe, sea level, I would recommend 52 or 55 pilot/158 main, and experiment with the shimmed needle. With a more open exhaust, I would run 55 or 58 pilot, shimmed needle, and 160 or 162 main...

I find that most 'hot ticket internet jetting tips' are on the rich side. Same deal with my 650R, the 'net recommendations were rich.

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Throttle response won't be that great with the stock corked pipe. These big bores have to breath to get decent throttle response/low end snap. Unfortunately, that means increased sound output...

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Thanks

I just picked up a spare carb with: 55s pilot, 175 main, slide ported 5/32, and a 55k needle shim. I picked the carb up as a spare to experiment with and in case the CA smog nazis decide to have bikes smogged i can throw the stock one on.

Your thoughts on this current carb setup? I am at sea level in CA but most of my offroad is done at 1000-3000 feet.

Suggestions? This whole jetting thing is completely new stuff for me! Is there an idiots guide to it online anywhere? :devil:

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Hey Mangler. I would like to give my endorsement of mods. Jetting, and exhaust will give you a completely different and better running bike. The exhaust I run on my bike, and highly recommend, is the Yoshi full system. After that you will be hanging on for dear life!!!!

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how does it perform with a stock exhaust?

i was going to do the Dave mods, desmog, desnorkel, and add a uni air filter but i want to keep my stock pipe for awhile! call me crazy, but i like the quietness. will i regret this?

anyone running like this?

thanks

On my 600 I have the stock exhaust pipe, but I replaced the baffle with an aftermarket one that I got from Baja Designs. I think that they were available for the 650L too. With some rejetting, it really helped the bike. I think is is sort of in between the stock unit and a full aftermarket pipe. The baffle flows better, but it is still rather quiet. I didn't want a really loud pipe. I believe that it is a good compromise. Unfortunately Baja Designs doesn't list them on thier site anymore.

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thanks, i have removed the baffles on my older XR250's and such, but the 06 L model baffle appears to be tack welded in there! hmmmm

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Just cut the tacks and you can remove and replace the baffle as you choose. I ran my L with the carb mods and de-snorkeled with the stock pipe and no baffle for 15,000 with no problems. I would agree with the "a little rich" comment above.

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how does it perform with a stock exhaust?

i was going to do the Dave mods, desmog, desnorkel, and add a uni air filter but i want to keep my stock pipe for awhile! call me crazy, but i like the quietness. will i regret this?

anyone running like this?

thanks

Yep. Me.

  • Dave's Mods (Thanks Dave!)
  • De-Smog
  • De-Snorkel
  • Stock paper element filter for now (I did pick up a UNI)
  • 14-tooth
  • Stock header and muffler/arrester minus the baffle

Runs great! (with or without the baffle)

I'm around 5-600 ft ASL.

Personally, I feel that the stock muffler/arrester has plenty of flow for most riders. It's main negative trait is its weight, but I don't do triples on the L anyway. Some replace them since they think they are ugly. I just like to ride.

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For those of you who have performed "Dave's Carb Mods" on your XR-L, have any of you had any problems at all related to them? I've done a good bit of searching and haven't read anything negative yet, but thought I'd ask - just in case.

I recently picked up a '93 XR650-L and have been reading all the glowing comments regarding "Dave's Carb Mods". The previous owner had put an old external disc Supertrapp pipe on there (currently with only 5 discs in) and says he rejetted for it - but I don't know what size jets are in there. The smog pump is already gone and the airbox snorkle removed, but the stock air filter was in there. I've replaced that with a Uni foam filter. Sounds like all that's left for me to do is drill the slide, shim the needle and check the jetting.

No negatives. My friend and I both did Dave's mods on our 650L's. We run mostly in the woods near Houston at about 100 feet above sea level. We once had the bikes at 8000 to 9000 feet in Mexice and only noticed a slight loss of power at those altitudes. Of course that could be adjusted if we ran at those altitudes all the time.

Mac

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Ill tell you that i dont have a XR-L but have ridden with dave.... and i must say he's got his xr-l perfect......stock pipe(dont know if thats modded or not) and all. on one spectrum He's super fast and on another can lug around like a tractor making his own trails as if he's riding a tryials bike. Great rider on a modded B.R.P. he can smoke me on my bike at any time in any conditions.......

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