Dave's mods

[Dirkdelange]

Double Bells for Dave and his partner for the carb mods and sharing it with the rest if the world.

After doing all the uncorcking and airflow mods, I did the carb mods. 2 years later and doing ALOT of testing and changing jets and stuff I came to the conclusion that I could not get the bike to run any better.

Anyone that's still pondering about how to get your pig to go better, follow the instructions and just leave it as is.

Thanks to everyone for sharing their info with others to get our pigs to blow dust in the eyes of the rest.

Up with a Bells to you Dave

[frioman]

I just finished Dave's mods yesterday -- Honda XR650L, carb (5/32, .025 needle shim) with mixture at 2 1/2 turns, 55 & 160 jets, smog removed, FMF Powercore exhaust, De-snorkeled, K&N filter I was already using.  My first time to do stuff like this; especially, the carb.  I turned on the fuel petcock and wondered how long I would have to crank before it would start, and would I have to adjust the mixture to get it to start. 

 

To my surprise, it started almost immediately. Bam!  I couldn't believe it. I only let it run for about 15 seconds because I need to allow the high temperature silicone to dry on the exhaust.  I can't wait to check it out and see if any adjustments are necessary.  I'm at 70 feet above sea level.

 

Many thanks to Dave's mods.

Edited May 29, 2015 by frioman

[dman3998]

do yourself a favor and toss the K&N in the trash and get at least a UNI which is still not great compared to an OEM paper element to catch fine dust.  The K&N is "OK" for slab where you really only need to sift out the pigs and chickens.  but if you ride off road in dusty conditions it will allow most of the fine stuff through and bring your motor to an early death.   I am not speaking out my backside either read this and decide for yourself

 

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

 

I also firmly believe it caused my L motor to wear out way sooner than it should have

[XR650L_Dave]

The mods used to be the 'standard recipe', then Dynojet started putting out jet kits and the knowledge of the one true faith faded... but it was preserved, in bits and pieces, on the XRLUG yahoo group.

 

All I did was piece the old lore back together, and I think Brian did more work in taking the pics than I did doing the rest.

 

Now the super secret airbox breathing mod and taking out the baffle, and putting back just the big cone 'washer' on the end for the perfect not-loud sound with a bit of extra top end, all mine.

[mcma111]

frioman,

 

You might be a bit rich with the 160 main. Might try a 158.

[frioman]

Mcma111, you may be right. I removed the plug yesterday, and while close, the plug color doesn't quite match the photos of what is considered normal -- it's slightly toward the darker side (slightly).

[timbo_slice]

do yourself a favor and toss the K&N in the trash and get at least a UNI which is still not great compared to an OEM paper element to catch fine dust.  The K&N is "OK" for slab where you really only need to sift out the pigs and chickens.  but if you ride off road in dusty conditions it will allow most of the fine stuff through and bring your motor to an early death.   I am not speaking out my backside either read this and decide for yourself

 

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

 

I also firmly believe it caused my L motor to wear out way sooner than it should have

My boss always gave me crap for having a K&N on my truck, said an old mechanic he knew swore they could ruin your engine in dusty places. Finally a good article that backed that up! Going to go by an OEM paper filter right now. Sorry this is irrelevant, but I always use the UNI filters on my bikes!

[mikesbaron]

Where are Dave's carb mods located? 

 

HERE:

 

 

http://www.mediafire.com/view/dtymwoj2mxt/Daves_Mods.pdf

Edited June 10, 2015 by mikesbaron

[XR650L_Dave]

Really here...

 

http://www.4strokes.com/technical/honda/xr650l/daves-carb-mods/

http://www.4strokes.com/technical/honda/

 

The PDF is handy, though!

[Eric98391]

So I just bought a new/leftover 2014, will these mods work on this bike? I read somewhere on here about a D-shaped jet/screw on my carb, where do I get the tool for that? Also are the Dynojet jets the same as the Keihin ones number/size wise? I have a bunch of parts coming and want to do all this at the same time. Thanks.

[EarthCruzn]

This is a pretty common chart for refference ;

NOTE: My mechanic told me "back in the day" your needle needs to be made by the same company (or design) as the jet you are using (I have always follow his advice and has prevented rich/lean "can't seem to get it right" issues)

(((FOR THE RECORD: In my  08' XR650L w/FMF Q4 & Uni filter....... I am using a DynoJet DNO130 needle on the thrid position (from top) with a DynoJet DJ165 main. [i also have the DynoJet replacement (light) spring. Fuel screw is at 2 1/2 turns out.]

 It is running and burning fuel perfectly..................I did not do "Dave's Mod's". I wanted a reversable if needed option)))

 

Quote "Your needles and jets need to be matched up always.... they are designed to work together, properly matched jets, needles, and good emulsion tubes are crucial."

IMO as this has been my experiance (It does make sense though). Maybe thats why "Joe" using Keihen jets with a Keihen needle has a different jetting set up than "Frank" with Mikuni jets and a Keihen needle.

 

i.e.- From what I have seen elsewhere, all three use a different coding method,

- Mikuni jets are marked with their flow rate - ie: 150 = a rating of 150 cc of fuel per minute.
- Dynojet jets are marked with the diameter of the hole in the jet - ie: DJ150 = 150mm hole.
- Keihin, well, I haven't seen a good rationale for these......maybe someone else can chime in........

...anyway here is the chart:

 

Width------Keihin # -- DynoJets # -- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5
 

Edited June 21, 2015 by EarthCruzn

[EarthCruzn]

 MotionPro........... I think its like $14.00 ( you can make one using a plastic red wire crimp connector, heat it up slide it on let it cool down and turn it) some say a modified.22 cal shell casing works

[Eric98391]

Thanks for the chart, one of the things I have coming is the Dynojet kit, also have a FMF Q4 and a foam air filter. I should have mentioned I ride mainly between 2000-4000ft.

[ScottRNelson]

- Dynojet jets are marked with the diameter of the hole in the jet - ie: DJ150 = 150mm hole.

Ummm....  The cylinder for the XR engine only has a 100 mm "hole". 

Edited June 22, 2015 by ScottRNelson

[EarthCruzn]

Scott, I am not sure how their numbers are applied, yes I was wondering the same but did not alter the quote. maybe 100mm/w by 50mm/d ??

(or maybe it's 1.50mm and the decimal was a typo.......... as it is applied to the "diameter of the hole in the jet " )

 

Just like " Mikuni jets are marked with their flow rate - ie: 150 = a rating of 150 cc of fuel per minute." (how are they determining that??? does a XR650 pull the same vacuum as a XR250?? { I would not think so but it is the same jet that is used}

 

I did not question the reasearch, or the application............. I just install the damn things ?

[frioman]

I'm still enjoying Dave's Mods.  It's like I have a different bike.  Wow.  And then...on top of the mods, I'm now using a 48T rear sprocket with a 15T front.  Just right for my riding.  Thank you again Dave.

[lazypengu1n]

I just finished Dave's mods yesterday -- Honda XR650L, carb (5/32, .025 needle shim) with mixture at 2 1/2 turns, 55 & 160 jets, smog removed, FMF Powercore exhaust, De-snorkeled, K&N filter I was already using.  My first time to do stuff like this; especially, the carb.  I turned on the fuel petcock and wondered how long I would have to crank before it would start, and would I have to adjust the mixture to get it to start. 

 

To my surprise, it started almost immediately. Bam!  I couldn't believe it. I only let it run for about 15 seconds because I need to allow the high temperature silicone to dry on the exhaust.  I can't wait to check it out and see if any adjustments are necessary.  I'm at 70 feet above sea level.

 

Many thanks to Dave's mods.

I also just completed Dave's mods on my bike yesterday. I'm running 60 and 160 jets, FMF PowerBomb and Powercore, K&N (I have a Uni-Air but didn't realize it needs to be oiled, ordered oil) Smog NOT removed (XRsonly is really slow! ETA for parts is July 2nd) 

 

My bike started right up, sounded mean as hell. Only thing I am wondering about is when snapping the throttle off idle I get a slight bog then it revs up no problem. I wanted to know if you had any issues snapping the throttle of off idle at all running the 55 / 160 combo.?

 

I am considering moving back down to the recommended jets of 55 / 158 but that I go to the next level since I have the headers too.

 

I don't plan on playing with the jetting until the smog is removed. Any recommendations guys?

Edited June 29, 2015 by lazypengu1n

[ScottRNelson]

I don't plan on playing with the jetting until the smog is removed. Any recommendations guys?

Personally, I find it harder to get the carburetor back in place and everything hooked up right than to just remove the smog parts.

 

I don't think the smog parts effect performance much either way, though.

 

Did you drill out the slide?

I haven't done that to mine yet and am curious if it has a positive or negative effect when snapping the throttle open at idle.  Consider raising your idle speed a little as well.

[frioman]

I have no bog at all, but my spark plug looks a little lean with the 158 jet, and this is before I replace the K&N with a Uni-filter. I'm going to take my plug to the local Honda shop and ask a mechanic to give me their opinion. I had no bog with the 160 jet either, but it looked a bit rich -- that's the only reason I went to a 158 jet.

What is your elevatation? Did you de-snorkel?

I'm a novice and removing the smog went fine.

[lazypengu1n]

Personally, I find it harder to get the carburetor back in place and everything hooked up right than to just remove the smog parts.

 

I don't think the smog parts effect performance much either way, though.

 

Did you drill out the slide?

I haven't done that to mine yet and am curious if it has a positive or negative effect when snapping the throttle open at idle.  Consider raising your idle speed a little as well.

 

I did drill the slides out using a 5/32 drill bit.

 

I'm not sure at the moment because most people who run Dave's mod have removed the smog. I haven't with my current setup, when I try to snap the throttle I get a sudden bog and then it revs ups. Kinda like skipping a beat. I am not sure if it's a combo of the K&N + Smog + 60 and 160 jets.

 

I have no bog at all, but my spark plug looks a little lean with the 158 jet, and this is before I replace the K&N with a Uni-filter. I'm going to take my plug to the local Honda shop and ask a mechanic to give me their opinion. I had no bog with the 160 jet either, but it looked a bit rich -- that's the only reason I went to a 158 jet.

What is your elevatation? Did you de-snorkel?

I'm a novice and removing the smog went fine.

 

I am running a new spark plug - NGK DPR9EIX-9 | PO had a K&N filter and I currently looking for Foam Oil to use on it. Short week due to July 4th and I'd like to be able to test it.

 

Elevation 184 ft - I have removed the snorkel.

 

I plan on doing the Smog removal. I'm waiting on parts to come in. XRsonly is great, but very slow shipping.