DR650SE Index Topic #10- CARBURETOR/INTAKE

Discussion in 'Thumpers' started by Krusty ..., Nov 8, 2010.

  1. sagedrifter

    sagedrifter Southern Explorer

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    I'm guessing its a DJ 160 main? Thats usually run with an after market pipe. It could be a 160 Mikuni which would be very fat.

    I would use a DJ 155 or a Mikuni 145 main jet with a cut air box and stock exhaust. If your getting 30 mpg, something else is wrong though. Your only on the main jet when the throttle is well open. The needle controls the economy the most.

    With the stock exhaust, I would try the needle in the middle or 3 down from the top. If your at 4, there should be two open notches below the E-clip.

    I always like the 4th position though.

    The carb is leaking some where, I would just replace the float o-rings with OEM parts, check the float needle. Does it seal when you blow on the fuel line? If its original, I would just replace it. Put a fresh OEM stock pilot jet in, I think thats a 42.5.

    www.cheapcycleparts.com has the parts, I usually get my jets through them. Motolab in the vendors section sells the correct o-rings and jets too.

    If I go into a carb, I just freshen every thing up. It seems like the o-rings last about 3 years now with the ethanol blends. My bowl seal just failed this year, it was like hard plastic after 4 years. The ethanol eats up the fuel hose too, so I tend to replace rubber stuff at least before three years. The float needle is rubber tipped also. I've been running marine stabil for the last two years off and on and it does help greatly to keep things lubed.

    I always get 47 mpg or better.
    #61
  2. Nessman

    Nessman Evangelical Atheist

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    Ethanol....I hates ethanol.

    I'll take your O-ring advice and see what happens, smaller jets if that doesn't help.
    #62
  3. sagedrifter

    sagedrifter Southern Explorer

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    The stock main is a 140, the 145 Mikuni works fine with a cut air box. I always thought the DJ 155 was a bit rich, the 160 DJ would be really rich with stock exhaust. Probably had a slip on before and the original owner put the stock pipe back on without reducing the main to a DJ 155?

    If you need to change the main, I would get OEM. Make sure the needle only has the e-clip and the white plastic spacer was left out.
    #63
  4. Nessman

    Nessman Evangelical Atheist

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    I ordered the kit from ProCycle yesterday, it was in the mailbox this afternoon.

    :clap

    Now to find time to put it in.
    #64
  5. Bronco638

    Bronco638 Nobody Home

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    I know that Kris and Nordie Boy already posted similar charts (Kris on Page 1 Post #3 and NB on Page 2 Post #30) but I found a more comprehensive one, courtesy of motolab, (here) and thought I would share.

    <table border="1" cellpadding="2" cellspacing="2"><tbody><tr align="center"><td>Width (in.)</td><td>Keihin #</td><td>DynoJet #</td><td>Mikuni #</td></tr> <tr align="center"><td>0.054</td><td>140</td><td>130</td><td>121.9</td></tr> <tr align="center"><td>0.055</td><td>142.5</td><td>132</td><td>123.8</td></tr> <tr align="center"><td>0.056</td><td>145</td><td>134</td><td>125.6</td></tr> <tr align="center"><td>0.057</td><td>147.5</td><td>136</td><td>127.5</td></tr> <tr align="center"><td>0.058</td><td>150</td><td>138</td><td>129.4</td></tr> <tr align="center"><td>0.059</td><td>152.5</td><td>140</td><td>131.3</td></tr> <tr align="center"><td>0.06</td><td>155</td><td>142</td><td>133.1</td></tr> <tr align="center"><td>0.061</td><td>157.5</td><td>144</td><td>135</td></tr> <tr align="center"><td>0.062</td><td>160</td><td>146</td><td>136.9</td></tr> <tr align="center"><td>0.063</td><td>162.5</td><td>148</td><td>138.8</td></tr> <tr align="center"><td>0.064</td><td>165</td><td>150</td><td>140.6</td></tr> <tr align="center"><td>0.065</td><td>167.5</td><td>152</td><td>142.5</td></tr> <tr align="center"><td>0.066</td><td>170</td><td>154</td><td>144.4</td></tr> <tr align="center"><td>0.067</td><td>172.5</td><td>156</td><td>146.3</td></tr> <tr align="center"><td>0.068</td><td>175</td><td>158</td><td>148.1</td></tr> <tr align="center"><td>0.069</td><td>177.5</td><td>160</td><td>150</td></tr> <tr align="center"><td>0.07</td><td>180</td><td>162</td><td>151.9</td></tr> <tr align="center"><td>0.071</td><td>182.5</td><td>164</td><td>153.8</td></tr> <tr align="center"><td>0.072</td><td>185</td><td>166</td><td>155.6</td></tr> <tr align="center"><td>0.073</td><td>187.5</td><td>168</td><td>157.5</td></tr> <tr align="center"><td>0.074</td><td>190</td><td>170</td><td>159.4</td></tr> <tr align="center"><td>0.075</td><td>192.5</td><td>172</td><td>161.3</td></tr> <tr align="center"><td>0.076</td><td>195</td><td>174</td><td>163.1</td></tr> <tr align="center"><td>0.077</td><td>197.5</td><td>176</td><td>165</td></tr> <tr align="center"><td>0.078</td><td>200</td><td>178</td><td>166.9</td></tr> <tr align="center"><td>0.079</td><td>202.5</td><td>180</td><td>168.8</td></tr> <tr align="center"><td>0.08</td><td>205</td><td>182</td><td>170.6</td></tr> <tr align="center"><td>0.081</td><td>207.5</td><td>184</td><td>172.5</td></tr> <tr align="center"><td>0.082</td><td>210</td><td>186</td><td>174.4</td></tr> <tr align="center"><td>0.083</td><td>212.5</td><td>188</td><td>176.3</td></tr> <tr align="center"><td>0.084</td><td>215</td><td>190</td><td>178.1</td></tr> <tr align="center"><td>0.085</td><td>217.5</td><td>192</td><td>180</td></tr> <tr align="center"><td>0.086</td><td>220</td><td>194</td><td>181.9</td></tr></tbody></table>
    #65
  6. Nessman

    Nessman Evangelical Atheist

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    Last tank was @35mpg, we're making progress. Thanks for the O-ring advice.:freaky

    Next step is a stock shimmed needle and 145 main.
    #66
  7. sagedrifter

    sagedrifter Southern Explorer

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    If the petcock is stock; Make sure the petcock is not back feeding through the vac line and make sure its not leaking when it shoud be off.

    35 mpg is BAD.... :eek1 No need for the stock needle, the DJ needle ain't causing 35 mpg. The stock needle sucks.

    I bitched when I saw 42 mpg, it was the float o-rings.:deal

    Normal BST carb economy for me was 45 to 47 mpg jetted and with my fat but over the pegs while the right hand twisted the throttle often...

    You could always just order a TM40 from Procycle...
    #67
  8. Nessman

    Nessman Evangelical Atheist

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    52MPG :D

    New O-rings got me from 30MPG to 35MPG, swapping the 160 main jet for a 142.5 (shop didn't have a 145) put me over the top.

    It doesn't have quite the stomp it had but it's still fun. I might go to a 145 some day but I'd rather do the TM40 carb swap :deal

    Thanks sagedrifter.
    #68
  9. Mambo Dave

    Mambo Dave I cannot abide.

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    Here's what I'm running - or plan to run - and wouldn't mind some input:

    My bike has a DG exhaust and a 165 main jet with the air/fuel screw turned out a little by the previous owner. He also ran it with the side-plate off of the airbox... and this is the way mine sits now. Both he and I are worried it is lean in the mid-ranges since he didn't shim up the stock needle, but the bike runs absolutely great (maybe too great - don't want to urn a hole in the piston here...)

    I just ordered the pro-cycle DJ kit for mine.

    My plan is to open the top of the airbox up and put that side-plate back on. I run at sea level to... sea level. Florida doesn't change much.

    How rich of a DJ (in the kit) main should I go, what initial clip setting do you suggest I use (DJ needle), and the stock air filter seems pretty free-flowing... so would there be any benefit to any other air filter out there?

    [​IMG]

    This bike will have a 16-tooth sprocket, and be usually run at 80 to 90 MPH for about 30 minutes at a time twice a day (slower on weekday mornings when I get caught in traffic), so it probably won't ever be wide-open-throttle, but it will be really open. Eventually it will get a 17 tooth sprocket when I convert it over to a 520 chain, but as this OEM chain only has 2900 miles on it, I figured it would be worth using a 16 tooth for now.
    #69
  10. NordieBoy

    NordieBoy Armature speller

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    160 main and 3rd from top to start with and fine tune from there. Mixture screw to suit.
    The stock filter works ok but others like the TwinAir work better.
    #70
  11. jessepitt

    jessepitt Ride More

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    I have a whopping 200 miles on my new DR650 and the low speed/throttle surge was killing me. I cant afford a jet kit yet so I decided to shim the needle. I had done this on my previous DR650 so I new it was easy and I figured I would take some pics of the process to help those who have yet to do this including my little brother who just picked up his new bike yesterday! If that surge bothers you this trick eliminates most of it. I forgot what a great difference it makes, night and day! It is very easy to do as I said; first remove the side panels, then the seat then the tank. Be sure to disconnect the small vacuum line from the carb to the petcock and don't worry about emptying the tank as the vacuum petcock will not flow without the engine running.
    Once you have it stripped down you can easily see and access the carb. Be sure to clean the area around the carb so no contaminates make it inside your carb while you are working on it.Then loosen the cab boot clamps on either side of the carb and rotate the top to the left side of the bike, you may need to loosen or remove the plastic reusable zip-tie that holds the throttle cables to the frame. That will allow more rotation without damaging your cables. Once you have the carb rotated so that you have a clear shot at the cap remove the two screws holding the cap in place. Be aware that there is a spring under the cap so press down on it while removing the screws.
    [​IMG]
    now you should be here:
    [​IMG]

    Under the cap is the diaphragm which is very delicate so proceed with caution and keep everything clean. Remove the cap and the spring then gently pull up the diaphragm which is connected to the slide.

    [​IMG]

    [​IMG]

    Here is the slide/diaphragm/needle assembly:
    [​IMG]

    The needle just sits down in the slide and is held down by the spring so to get it out just tip the slide and it will fall out. Once you have the needle out you will see a plastic spacer and a c-clip. Remove the c-clip and slide the spacer slightly down the needle and place a thin stainless washer on top of the spacer and replace the c-clip, then snug them all tight to the c-clip:
    [​IMG]

    I used a plastic washer from another carb I had laying around but any thin washer will work as long as it wont rust.
    When you drop the needle back into the slide you may notice that it does not hang straight down from the slide. This is due to a shoulder inside the slide. I don't know the purpose for the shoulder but as we are not changing the seating surface I don't think it is a problem. I have heard that some people cut there spacer so that it fits past the shoulder and sits flat but that would require a thicker shim and I feel like there must be a reason for the shoulder so I left mine alone. The reassembly is easy. Just drop the slide back into the carb. Make sure the the diaphragm is sitting flat and even around the top of the carb body and does not get pinched when reinstalling the cap. Also of note: there is a tiny o-ring that seals the vacuum line connection between the carb body and cap. It is visible in the third picture. Be sure not to loose or pinch this little guy. Other than that there aren't any tricky parts, just be careful not to pinch any vacuum lines when you rotate the carb back into place. You will know the carb is aligned correctly when the bump on the front of the carb neck aligns with the corresponding notch on the carb boot.

    While I had the carb rotated to do the needle shim I decided to go ahead and remove the plug over the fuel screw and install an extended full screw I had from another carb. The extended screw can be purchased from procycle.
    First it is drill (by hand) the little brass cover plug:
    [​IMG]

    [​IMG]

    Once you have CAREFULLY drilled through this plug you can CAREFULLY thread a small screw into the hole.
    [​IMG]

    Grip the screw with pliers and twist/tug out it comes!
    [​IMG]
    Easy, and now you have the ability to adjust your fuel screw.
    This pic illustrates why an extended fuel screw is nice. Getting to that little bugger while the engine is hot is no fun:
    [​IMG]

    Extended vs. regular screw:
    [​IMG]



    Anyway, I hope this helps a few folks with their low speed surge. It really does make a huge difference and doesn't cost anything, also it is a good way for new DR owners to get a feel for their bikes and show you just how easy they can be to work on.
    #71
  12. sagedrifter

    sagedrifter Southern Explorer

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    I would not ride a stock needle carb with the cover off. That would be way too lean. Very lean! The DJ needle is totally different and much better than the stock USA needle.

    Put the cover back on ASAP. With an open air box you need a jet kit with the adjustable needle. Taking the side cover off produces extra noise and surging. Don't kill the poor thing... Its amazing how much abuse the DR650 can take.

    The exhaust doesn't really matter, its the added air from the intake that matters most. The needle should be at 4 just like the directions will say. The procycle kit uses mikuni jets. The 160 works fine. You can run the needle at 3 or the middle position, but in my experience its too lean and surges more for Florida. I prefer the 4th notch, that's two up from the bottom or 4 down from the top.

    Have fun... :D

    Sent from my GT-S5690L using Tapatalk 2
    #72
  13. Mambo Dave

    Mambo Dave I cannot abide.

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    I did as you suggested, and it may have nearly got me killed tonight. It's either the cover, or that Sea Foam added to the fuel tank earlier in the day dislodged some varnish or debris and is blocking some part of the carb.

    I put the cover back on and just assumed everything would be fine for my 40-mile ride in to work tonight. Instead I ended up in a terrifying position of a bike that would sputter at about mid-throttle, so the best I could do was an indicated 70 MPH (give or take 3 MPH... slower up gradual hills or into the wind, best speed of 73, once, when I got lucky) which is way, WAY too slow on a Florida super-slab. I was just waiting for someone to rear-end me with them doing a real 85 MPH while I was probably only doing 63... if that. In the 35 miles of highway I was passed by everything except about 3 cars...

    I will take the cover back off to see how it runs... I've got a funeral to make it to tomorrow morning, so it would be ideal if the bike would run the way it was running before I put the cover back on... I don't have the time to go this slow, and tomorrow morning's run south is in rush-hour traffic.


    ----

    As it was, I had no surging with the plate off, and the bike ran very well - better than most DR's I'd guess. But the bucking-bronco I tried to ride in to work was a whole different story... I finally learned to only turn the throttle to a certain point, and no more - no matter what.... that made for a long and dangerous ride.
    #73
  14. sagedrifter

    sagedrifter Southern Explorer

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    Well, you are running a 165 main of some sort? So, yes at heavy throttle use it would be too rich with the cover on. BUT... At moderate throttle you are very lean with the cover off.

    You would be very, very lean when in the needle, if its a stock needle with an open air box. I would not run it like that.

    You would be better off running a mikuni 140 main or a DJ 150 with the stock needle and a stock air box with the dg exhaust.

    If it was mine, I would NOT run a stock needle with the air box cover off. Even with the needle shimmed I would leave the air box intact.

    The needle controls mid throttle, the main jet comes into play at interstate speeds.

    The air box should only be opened when you have a jet kit. Other wise leave the main alone. You can shim the needle and pull the snorkle.... any more than that .... Add a jet kit.

    Sent from my GT-S5690L using Tapatalk 2
    #74
  15. Mambo Dave

    Mambo Dave I cannot abide.

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    Thanks. I am kinda of stuck for the moment - I need the power to stay alive for the ride home. I just tested it with the cover back on and off, and sure enough it does cut out after about mid throttle (even without the RPM's up).

    I guess mid-range will be lean, but apparently my normal cruising RPM's are well above mid-range or I wouldn't keep hitting a wall.

    Thanks for the help. I have the ProCycle jet kit on order, so hopefully a little lean running in the mid range won't kill it. I bought this bike to rely upon for commuting, so it has to be on the road... parking it isn't an option. Maybe tomorrow I'll shim up the needle for the time being.
    #75
  16. ER70S-2

    ER70S-2 Long timer

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    Sounds to me like something is in the main jet, an easy fix. Maybe :deal
    #76
  17. Mambo Dave

    Mambo Dave I cannot abide.

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    Yeah, it did seem like it, but taking off the airbox cover solved it... so I'm going with lack of air once the main jet kicks in - and apparently that's the zone in which I ride.
    #77
  18. sagedrifter

    sagedrifter Southern Explorer

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    Keep in mind that taking the side cover off and cutting the top open are not the same thing. Once properly opened up, it will have less intake noise and less prone to surging. Try not to loose the capture nuts.

    It actually runs fine stock with the pilot screw backed out some. I just hated the lean surge at light throttle. Once I did my first DJ kit it ran much better but my 50/54 mpg went to 45/47 mpg. But I did add exhaust too with a 160 main and the needle at 4. Just like the directions. After a years of that and trying the 3rd notch, I switched to a TM40, no more surge, no more vacuum hesitation, better fuel economy. No more need to tinker.... :D

    Sent from my GT-S5690L using Tapatalk 2
    #78
    biker128pedal likes this.
  19. Mambo Dave

    Mambo Dave I cannot abide.

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    LOL, sounds good... but I'm at something like 37 or 36 MPG. I swear my speedo is wrong, but if it isn't then I'm doing 90 to 95 most of the way to work with the 15-tooth front sprocket and a very, very worn rear tire. Rear tire should be changed out today for a taller one, and 16 tooth sprocket should be here later this week... I didn't buy the bike for any extra fuel mileage, but it would be nice if I could get it.

    I tend to believe that for most bikes, no matter the cc's or cylinders, to push a human who sits upright at 85 MPH - with no windshield - pretty much takes the same amount of fuel on most bikes, and that will be at, or just below, 40 MPG. My three bikes all get about the same MPG for the speeds I run. If I slowed down to 55 MPH or so then that's where I'd see the differences in fuel economy.
    #79
  20. sagedrifter

    sagedrifter Southern Explorer

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    I got 46 mpg riding my big fat FJR to work in Daytona. I hit 80 plus in 70 zones often. The bike actually ran at 90 very relaxed. 120 came easily.

    The DR650 is better at a true 65/70 mph. Any more and the economy drops like a rock. I cruise at 70 and get about 47 mpg on trips. Under 65 mph means over 50 mpg for me. I have to ride really hard to see less. Sounds like you need a big standard or a sport touring bike.

    If your staying over 80 mph indicated a bunch, get a 16t CS and find a faster bike soon. Like an old Black Bird or at least an old VFR etc... I liked the FJR1300 since it was shaft driven.

    The poor old DR650 is not made for sustained high speeds.


    Sent from my GT-S5690L using Tapatalk 2
    #80