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deddy
Payson, UT
USA
41 Posts |
Topic started on 04/04/2004 at 8:15:35 PM
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I have already removed the smog, and drilled (5/32") the slide. I'll be getting a uni-filter this week. I plan to keep the stock exhaust.
I've been following these threads about rejetting the XR650L carb. The stock jetting (on mine) is 155 / 50 (short). It seems the hot setup is the 158 main and the 55 pilot. Can anyone report if these jet sizes will perform well at 5000'?
I too tried the DynoJet kit from Baja Designs, and it ran terrible. Maybe 'cause I have the stock Air Filter and exhaust. I went back to stock main jet and needle, and now I'll start trying keihin jets. But, will the 158 /55 work at my elevation?
thanks
Doug
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93 XR650L |
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winind
Snohomish, WA
USA
63 Posts |
Posted on 04/05/2004 at 3:46:47 PM
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| The Honda Service Manual provides jetting specs for extended high altitude riding. In theory, you would have to go leaner (smaller jets) due to the air being less dense (fewer oxygen molecules per cubic foot of air because of the lower atmospheric pressure). I will check my manual on CD tonight. |
93 XR650L - WB E exhaust w/12 discs, air pump removed, Uni filter, Renthal XR bend bars w/pad, anti-vibration bar ends, Jagg oil cooler, Dynojet kit (DJ160/50S) 2.5 turns out, needle at pos 3, custom rear luggage rack, Sunstar sprockets 15/45, Regina o-ring chain, Honda ss-7 fork oil (5 wt), Silkolene shock oil, IMS 4gal tank |
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winind
Snohomish, WA
USA
63 Posts |
Posted on 04/06/2004 at 07:14:15 AM
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| I checked the 650L service manual...they list a #150 main for high altitudes (Denver area?). Also the pilot needs to be screwed in about 3/4 of a turn from stock settings. |
93 XR650L - WB E exhaust w/12 discs, air pump removed, Uni filter, Renthal XR bend bars w/pad, anti-vibration bar ends, Jagg oil cooler, Dynojet kit (DJ160/50S) 2.5 turns out, needle at pos 3, custom rear luggage rack, Sunstar sprockets 15/45, Regina o-ring chain, Honda ss-7 fork oil (5 wt), Silkolene shock oil, IMS 4gal tank |
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TimBRP
Blackstone, MA
USA
495 Posts |
Posted on 04/06/2004 at 09:15:23 AM
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| I don't have a 650l but keep in mind that you'll be leaning this out if you replace the air filter and de-smog it. Also if you can open the exhaust up from stock form you'll need to richen also. |
'02 XR650R Uncorked
'99 Husky WR 250
'06 Yamaha WR450 |
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dave_cl
Central NY
USA
1214 Posts |
Posted on 04/06/2004 at 09:59:57 AM
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The service manual will be recommending jets that will be as horribly lean as it was stock, so don't go that lean!
the 158/55 may be a bit rich, but if you do the standard mods and put on an aftermarket pipe, it might get you right in the zone.
I prefer to start rich and home in on the right jetting by going leaner. |
'01 XR650L - keihin 158 main jet, 55 'long' pilot jet, screw out 2.5 turns, stock needle shimmed 0.035", slide holes drilled to 5/32, dynojet shorter CV spring installed, K&N filter, snorkel removed, stock exhaust, air pump removed, thermometer dipstick, MT21 90/90 front, huge mutant teraflex rear, 13-48 spkts. Central NY near Cortland
Articles: XR650L Carb Mods, DIY Dual Sport/Supermoto Helmet, XR650L Simplified Schematic for Safeties |
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deddy
Payson, UT
USA
41 Posts |
Posted on 04/06/2004 at 11:31:42 AM
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Thanks for all the comments....
I have ordered a 55 pilot jet and some main jets (158/160/162). I have now (just last night) installed a new UniFilter. I do not intend to open the exhaust, 'cause I don't want any more noise.
I took the bike for a ride last night and it seems to run much better with the stock jets (as opposed to the DynoJet kit from Baja Designs). I understand that the relatively poor performance of the DynoJet kit could be my own fault - by not improving the air filter / exhaust. I'm pretty sure the real problem with the DynoJet kit is the agressively tapered needle - with the kit installed it wouldn't hardly run in the mid-range.
Right now, the carb is stock, except:
1. stock needle is shimmed with the DynoJet shim
2. Slide holes are drilled out (5/32")
But, even returning to the stock jetting, I still have a 'miss' at full throttle. It seems to run well off idle and in the mid range (even up to 3/4 or 7/8 throttle). But at full throttle, it stumbles, misses and pops. Sounds like the main jet, I suppose?
I am curious about a 'starting point' for the main jet. I called both "XRs Only" and Baja Designs and I spoke with the technical support folks at both companies. I explained my poor results with the DynoJet kit and they pointed out that an opened up air filter and exhaust are required to take advantage of the kit - OK, I accept that. So I asked what they would recommend if I just wanted to try re-jetting with the stock needle. Here's what they recommend (both shops said essentially the same).
1. Shim the stock needle to raise it a little (.030??)
2. Use a 55 pilot jet - they don't sell the 's' model, so use the long
3. start with a 162 main jet
After pointing out that I ride at 4500 - 7000 feet (Utah) they thought maybe I should go down to 160 main jet. I am a bit surprised at these recommendations, since a few of you guys seem to be running the 158 main at much lower elevations.
BTW: Baja Designs told me that they used to add-in a 55 pilot jet to the DynoJet kit, but they had to stop because DynoJet wouldn't 'support' their kit if a dealer 'modified' it.
Here's my questions (thus far).
1. Can anyone comment (especially from experience) on the recommendation that I use a 160 main jet at my higher elevation vs. the common use of 158 at (what I assume are) lower elevations.
2. It seems to me that the stock jetting should be very lean, but, checking the spark plug after last night's 20 minute street ride (up to 65 mph) reveals not a light color, but black. (Today I'll be buying a new plug.) Also, the stumble I described above seems a bit out of place for a lean condition. With a lean main jet, I would have expected the engine to run smoothly, but with lower power and more heat. Maybe the old plug is just miss-firing at full throttle (high rpms). Does a full throttle stumble indicate lean main jet?
thanks
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93 XR650L |
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winind
Snohomish, WA
USA
63 Posts |
Posted on 04/06/2004 at 12:25:53 PM
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"Use a 55 pilot jet - they don't sell the 's' model, so use the long"
I was able buy a Keihin 55 pilot from the Honda shop. It is not the '50S', but the new 55 Keihin is the same length and diameter as the OE 50S.
I may change out the Dynojet and return to 55 pilot, 160 main, 2.5 turns out on fuel screw, but keep dynojet spring and not drill slide.
I had the same stumble/surge at half throttle with Dynjet kit (DJ160, needle 3 position) smog pump removed, uni-filter. In fact, the Honda shop had a tackle box full of Keihin jets. I bought all the incremental sizes from 150 to 165.
The surging went away after I installed the White Bros. E-series muffler, 12 discs. Now the bike really rips with dynojet kit, but it is very loud! The pipe does not fit well and hits the blinker. |
93 XR650L - WB E exhaust w/12 discs, air pump removed, Uni filter, Renthal XR bend bars w/pad, anti-vibration bar ends, Jagg oil cooler, Dynojet kit (DJ160/50S) 2.5 turns out, needle at pos 3, custom rear luggage rack, Sunstar sprockets 15/45, Regina o-ring chain, Honda ss-7 fork oil (5 wt), Silkolene shock oil, IMS 4gal tank |
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deddy
Payson, UT
USA
41 Posts |
Posted on 04/06/2004 at 1:09:47 PM
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Winind: what elevation do you ride?
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93 XR650L |
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winind
Snohomish, WA
USA
63 Posts |
Posted on 04/06/2004 at 2:00:10 PM
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| I ride between 0ft and 4,500 ft. Most of the time I ride close to sea level with occasional trips across mountain passes. I never noticed any problems on the highway up to 4500 ft. Once I rode up Harts Pass in Washington. Bike ran perfect to over 5500 ft. |
93 XR650L - WB E exhaust w/12 discs, air pump removed, Uni filter, Renthal XR bend bars w/pad, anti-vibration bar ends, Jagg oil cooler, Dynojet kit (DJ160/50S) 2.5 turns out, needle at pos 3, custom rear luggage rack, Sunstar sprockets 15/45, Regina o-ring chain, Honda ss-7 fork oil (5 wt), Silkolene shock oil, IMS 4gal tank |
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MrJimmy
CO Springs, CO
USA
14 Posts |
Posted on 06/03/2004 at 07:39:47 AM
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Deddy
I'm down in Colorado Springs and I have a similar problem. Except the bike runs fine once warmed up (10 min easy ridding) Does the stumble clear up at all or stay constant>? |
97 XR650L, CRF230F |
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Yeravener
SF Bay Area, CA
USA
96 Posts |
Posted on 07/04/2004 at 5:10:22 PM
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Recently picked up a California 04 XR650L w/ 2K miles, which the owner (lived at sea level) had done "some" air flow mods to. This is what he did: smog block off, removed the snorkle, installed DJ 165 main, DJ spring, and DJ needle on position 3 with DJ washer (0.020") underneath. He replaced the filter (looks like K&N) and installed a Big Gun Quiet silencer on the stock header.
He left in the 50 pilot jet and did not drill the slide holes to 5/32 or grind the air screw tab.
On a ride at my 2300 feet altitude, it exhibited a gnarly stumble off idle. When riding at low rpm and whacking the throttle open, the bike would cough until the carb went on a higher circuit, then would move out. Deceleration with closed throttle resulted in pops out of the pipe.
Yuk.
I have reinstalled the stock needle with the DJ washer underneath, drilled the slide, and will be installing a 55(short) pilot, if available from Honda, or a 55 (28mm) with slosh mods if not. The longer 55 is flush with the tube it screws into, but the slosh guard sits very near the jet opening (as noted in other posts). I will also put in a 158 main and set the air screw at ~2.5.
I will then jet with this setup:
Smog block off
No snorkel
K&N filter
2 slide holes drilled 5/32"
Stock needle with 0.020 washer
158/55 Keihin main/pilot
Slosh guard mod if necessary
Stock header
Big Gun Quiet silencer (may just go whole system before jetting..save me the trouble of rejetting later for the new pipe:-)
More to come... |
2006 KTM 450XC |
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radar2515
Carter Lake, IA
USA
118 Posts |
Posted on 07/05/2004 at 3:48:25 PM
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| ok sense we are on the subject of jets. i wanted to go to a much richer jet then im running now. like right now i think i run like a 138. the shop told me to leave it there because i can adjust the needle? to make it run 2 size jets bigger? doesnt make much sense to me. what do you think i should run? im no good with carbs. also if it makes any difference i live in iowa(elevation wise). thanks,kyle |
1983 xr500 - Pro Racing handlebars, grips, MSR bark busters, removed snorkel and baffle, wiseco piston, brand new topend. |
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