Dave's Carb Mods

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Korydh
Posts: 3
Joined: Jan 23, 2018
Location: Hillsboro Oregon
Rides: 2017 Honda XR650L

Re: Dave's Carb Mods

Postby Korydh » Wed Jan 24, 2018 11:28 am

Hello,

Glad to know there's still feedback on this subject. Looking for advice. I am a novice bike wrencher with a medium level of riding skill. I purchased a new 2017 XR650L, in fact it's so new I haven't ridden it yet because I'm waiting for a dry day to break in the engine (Oregon). I have purchased the smog removal kit and will wait until the bike has been ridden for a while to make sure there are no issues before I install them(warranty). I'm planning on getting a uni-filter or K&N improved airflow air filter. I plan on keeping stock exhaust, will do snorkel removal. Letting my bike idle there is very poor throttle response and I know I need to do something with the Carb. I've read about Dave's Mod and other carb improvements. Here is my question.....Is there anything new out there? I'm such a novice I just don't know.. I'm at sea level in mostly mild weather and would like to go up to let's say 1000' elevation. I've run the carbjets.com calculator and this is what they say I need: This Kit contains: one Main jet size 160 , one Pilot jet size 50 and 1 shim for each Slide Needle. They say to use two shims and say do not drill the slide.. Any opinions on that? Can I just not drill the slide and use an extra shim? What I see most doing at my elevation is 55/158. Sound more correct. Do you have any opinions on what brand jets to get and what works well?? What I was thinking of doing is getting a Keihin 99101-393 Series Main Jet 158 and a Pro X N424-26 Series Keihin Pilot Jet 55. And then either run two shims and don't drill the slide or do it like DM exactly..any input is appreciated and perhaps I'm barking up the wrong tree all together.. Please let me know.. this is my first carb bike. Thanks everyone.

Plud
Posts: 17
Joined: Oct 25, 2016
Location: Reno Nevada
Rides: XR650L
Vehicles: Jeep Wrangler, RAM 1500

Re: Dave's Carb Mods

Postby Plud » Wed Jan 24, 2018 11:54 am

First suggestion, use the <enter> key.. it's hard to parse that wall of text..

I have purchased the smog removal kit and will wait until the bike has been ridden for a while to make sure there are no issues before I install them(warranty).
Smog removal kit will not necessarily void the warranty, however you are a novice so it may be difficult to argue that. Smog removal doesn't buy much, except getting rid of the junk so IMO good call on waiting.

I'm planning on getting a uni-filter or K&N improved airflow air filter. I plan on keeping stock exhaust, will do snorkel removal.
I'd avoid the K&N, they filter poorly. UNI is IMO much better. The only reason to do the snorkel removal and Uni would be to get more top end power. Do you need it? If the answer is no or maybe, then I'd stick with stock at least until you start thinking "sure would be nice to have more power"..

Letting my bike idle there is very poor throttle response and I know I need to do something with the Carb.
It can take LONG time to fully warm up an XRL. Lots of oil to heat up, frame has to heat up..etc. When it's 50 out here, I have to ride for 30 minutes or more to get up to full operating temperature. Idling in the garage for 10 minutes isn't likely to result in full temp.

. I've read about Dave's Mod and other carb improvements. Here is my question.....Is there anything new out there? I'm such a novice I just don't know.. I'm at sea level in mostly mild weather and would like to go up to let's say 1000' elevation. I've run the carbjets.com calculator and this is what they say I need: This Kit contains: one Main jet size 160 , one Pilot jet size 50 and 1 shim for each Slide Needle. They say to use two shims and say do not drill the slide.. Any opinions on that?
That sounds a bit too rich. As far as I know 'Dave's Mod' is still the standard starting point.

Can I just not drill the slide and use an extra shim? What I see most doing at my elevation is 55/158. Sound more correct. Do you have any opinions on what brand jets to get and what works well?? What I was thinking of doing is
One thing you'll learn in time is, do one thing at a time. This is particularly important in carb tuning. You can do Dave's mod as is and be pretty close.

Here's what I would recommend:

* Stick with stock airbox, filter, exhaust.
* Remove carb, add one shim under the needle (I usually use #4 sae SS washers for this if I recall).
* Get the proper D bit for the idle screw, you'll probably need a right angle driver or flex driver to adjust while things are hot.
* Unblock the idle screw so you can adjust, how it's blocked can vary. I think mine was under a brass plug.
* turn idle screw out 1/2 turn while the carb is out of the bike and it's easy.

That should get you really close. Drilling the slide may help with throttle response, however I'd leave that for now. Goal at this stage is to get rid of the lean stock condition, which in my experience is typically idle and needle.

Wait until you can get some miles on it, I rode mine for 150 miles before touching the carb and I do these type of mods to every bike I've ever owned. I'm at 5000' so the lean issue wasn't as big an issue.

You may find that you want to switch out the carb completely, a lot depends on what kind of riding you do.. For example I ride mine like a dirt bike, lots of messy single track.. game trails.. rocky nasty slow speed stuff, the CV carb lag at really low throttle/speed was terrible.. so I installed a TM40 pumper which cleaned that right up.

Korydh
Posts: 3
Joined: Jan 23, 2018
Location: Hillsboro Oregon
Rides: 2017 Honda XR650L

Re: Dave's Carb Mods

Postby Korydh » Wed Jan 24, 2018 12:21 pm

Hey thanks Plud!!

Great advice. I'll do what you suggest and take it slow.. use one shim and not drill the slide for now.. I assume Keihin jets are good quality..

I'll check out the TM40 pumper if the time comes.. Thanks again.

Kory

Nornevrder
Posts: 3
Joined: Jan 28, 2018
Location: Spanish Springs
Rides: 2017 XR650L
Vehicles: 2012 Ram 2500

Re: Dave's Carb Mods

Postby Nornevrder » Mon Jan 29, 2018 6:34 am

Plud wrote:Fire away, I'd think there are others as well..

Hey dude I live in the Reno area and we sit at 5k and some change. I just picked up a 2017 and it seems to run pretty good. It’s got a little bog from zero throttle to WTFO. I’d like to gather a little more bottom. I’m going to start off with your jetting and go from there. Gas tank and then exhaust is next. Where about a do you live?

Plud
Posts: 17
Joined: Oct 25, 2016
Location: Reno Nevada
Rides: XR650L
Vehicles: Jeep Wrangler, RAM 1500

Re: Dave's Carb Mods

Postby Plud » Mon Jan 29, 2018 7:34 am

I did daves mod, removed snorkle and run UNI filter. Stock exhaust. When I replaced the stock carb it was at 158 main, 52pilot, 1.5turns out on pilot screw and one .022" shim under needle. It ran well with those settings, however perhaps a bit rich. The CV lag was annoying so I picked up a TM40 which after tuning with a wideband O2 sensor/meter 140main, needle 2nd from top.. Pilot is whatever procycle delivers with the TM40 kit. Took a ride through the hills yesterday, runs like a champ once warmed up properly. I purposely erred on the leaner side so that when riding at 8,0000+ it doesn't run too rich.

I'm in the old northwest. My bike is geared down (14/48), running tubliss and DOT knobbies. 99% off road setup. Most of my riding (other that short lunch rides) is loading up in my truck and heading out to the desert to explore interesting places like this: http://advrider.com/index.php?threads/1 ... a.1268839/

Depending on what kind of riding you like, might want to check out 'reno dualsport' on facebook and/or the local 'dust devils' club. Both seem to be more street/fire road type stuff. The organizer of 'reno dualsport' FB group (Dave, but not the Dave's Mod Dave ;-) rides single track and rougher stuff however it seems most of the people in that group are into easy stuff.

There's also an informal email group I ride with, most (maybe all) of the riders in that group are younger (I'll be 50 this year) and tend to ride faster (some a LOT faster) than I typically do. I can keep up, however I prefer a sedate pace... wife would kill me if I came home with broken bones.


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