DR350 Thread

Discussion in 'Thumpers' started by leonphelps, May 16, 2007.

  1. dapopa

    dapopa n00b

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    Hey guys, I have had my DR350SE for over 15 years. I bought it from a guy that had made the air ox mod but didn’t rejet it. Of course it would barely run. After I rejected her I decided that out of over fifty motorcycles I have had over the years she is my favorite.
    I was going to get her inspected so I could get new plates last week and discovered a turn signal not working and a burned out tail light bulb. After fixing those two irritations I put on my gear shoved the bike out of the garage hit the starter and nothing. She just sat there no sound no spark.
    I have been tracing wires, cleaning plug connectors and tracing wires for a week now. The battery is hot. The started relay is good. Jump it and the battery spins it like new. The kickstand switch and relay are working as they should. The neutral safety light is working as it is supposed to. I took the clutch switch off of it years ago. The main fuse is good.
    Has anybody had this happen and if so what the heck am I missing. I can sure use some help. I am down to riding the F650GS. I would much rather ride Suzy especially off road.
  2. plugeye

    plugeye MC rescue

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    it wont start because you keep calling it her & she
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  3. dapopa

    dapopa n00b

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    Well gee plugeye, I would rather ride a her then a he. Thanks for the help.
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  4. plugeye

    plugeye MC rescue

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    most folks ride it
  5. MrPulldown

    MrPulldown Long timer

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    Well going to go through the list of things that have kept my bike from starting, so bare with me if you have checked these already.
    -Handlebar right hand kill switch.
    -Pull the headlight cowl off and double check your clutch safety bypass. To bypass most just unplug the yellow wires to the lever's switch and reconnect to each other. The wires are actually too short and will pull apart if you turn the bars to full lock.
    -Check the negative battery terminal for micro crack.
    -How did the check the side stand safety switch (SSSS) and relay?
    -When you say no spark have you confirmed this or did it just not turn over?
  6. hoffguy

    hoffguy Adventurer

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    This just happened to me. I know you said kickstand relay is good but have you tried bypassing it? Mine died out of the blue despite having the switch bypassed. Went to start the bike and got no starter spinning. Power was getting through the start button, to the stand relay plug but not through the stand relay. I jumped Yellow/Black and Yellow and boom, back to normal.
    MrPulldown likes this.
  7. Sword777

    Sword777 Been here awhile

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    I had a post about a page or two back if someone can offer insight. I have a small fuel leak somewhere out of my carb. I see the gas pooling on the lowest part of the throttle shaft where the throttle cable connects. I know the float is the usual suspect, but this location appears to be below the throttle shaft, relatively, this shaft is above most of the carb, so not sure wtf is going on.
  8. colo79

    colo79 n00b

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    Sorry did not see this reply. I have fixed the magneto gouge by removing the shifter placing it in a vice and gently tapping it out a quarter inch. I will fixe the kick stand gouge next. The bike is a 95. Not sure on the rear sprocket, I just assumed everything was original. I bought the bike to see if it was something I wanted to get into, so far so good. Air filter has been replaced. I am still messing with the carb. I bought a different set of air jets and better results so far. It started right up but still wants to die when I touch the throttle. Last time I raised the needle with an additional plastic spacer but it seemed to bog down at lower rpms. Derek stated it could be flooding at that instant with the needle higher.

    So its starts great, needle is back to original height. If I touch the throttle it dies instantly, if I cover 60% of the air intake on the air box it will rev. Any suggestions are welcome. I believe the carb is set to the original setup and the fuel air screw is 2 turns out.

    Thanks
  9. markk900

    markk900 Been here awhile

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    Just a guess, but since that point is above pretty much all points of the carb containing fuel is it possible its coming from the gas tank? You mentioned it happens after sitting for some time so its not being blown there by wind during riding, so you might have a small leak from the tank.....
  10. Trixie

    Trixie Adventurer in my own mind

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    First off, are you sure you don't have any leaks in the intake? It sounds like the pilot circuit is lean. I had a similar experience, and replaced a brand new pilot jet with another, and problem solved. Is the fuel level in the bowl correct? A quick way to check is use some clear tubing connected to the carb bowl drain, then hold the tube up next to the carb and open the drain screw. The fuel level should be right around the seam between carb body and float bowl. There's a better way to accurately set this, but this is a quick ballpark method of checking.
  11. markk900

    markk900 Been here awhile

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    Sent this question to Derek and he asked me to post it here so everyone could see the discussion:

    Background: 1995 DR350SE (Canadian bike), BST33, 3x3 airbox mod, stock airfilter and exhaust, and Jesse needle. Stock (but new) pilot (37.5), Jesse extended fuel screw; needle clip in middle position; 135 genuine Mikuni main jet; new emulsion tube and slide guide; new float valve and seat.

    Question 1: bike pulls well in all gears from light throttle to WOT; I detect a hint of surging at steady throttle (barely open to 1/8), definitely better when warm. I tried going to a 132.5 MJ (I know - should not have an effect at this throttle opening) and definitely worse. Thought surging might be mechanical but it smooths out if I pull the clutch in so not chain, wheel bearings etc. Its very slight so not sure if I *need* to get rid of it but thought I would ask.

    Question 2: (maybe related to Q1): Bike idles great; starts well on enrichener when cold and takes a while to warm up enough to take throttle without enrichener. So I think we are in the right ballpark. But when the bike is warm I detect almost no effect of changing the fuel screw in or out. Started at 2.5 turns; went richer (out) and no change; went leaner (in) and no change until the screw was almost all the way in (0.5 turns or thereabouts). This does not seem right to me. Thoughts? I also wonder given this governs the very small throttle openings whether this may be causing my light throttle surge in Q1. The only part that has never been replaced on this carb at this point is the enrichener....could I be getting some residual extra fuel there?

    Anyway, appreciate any advice you may have.
  12. motolab

    motolab Long timer

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    Is it safe to assume that a Jesse needle is a Dynojet needle?
    Better when warm typically points to a lean condition.
    This confirms a lean condition.
    To throttle means (from Webster's):

    a (1) : to compress the throat of : choke (2) : to kill by such action
    b : to prevent or check expression or activity of : suppress
    throttle creativity>
    2
    a : to decrease the flow of (as steam or fuel to an engine) by a valve
    b : to regulate and especially to reduce the speed of (as an engine) by such means
    c : to vary the thrust of (a rocket engine) during flight

    intransitive verb
    : to throttle something (as an engine) —;usually used with back or down <the pilot="" <i="">throttled back

    I therefore assume that by "take throttle", you must mean "take opening the throttle". If so, sounds good.
    Try with a digital tachometer and/or try measuring CO.
    The pilot jet most strongly affects 1/8 opening - the fuel screw up to 1/16 or so.
    Not likely, since we have established that the symptom is due to a lean mixture.

    Regards,

    Derek
  13. markk900

    markk900 Been here awhile

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    Thanks Derek: you had two questions in there which I will try to answer: The "Jesse needle" I purchased from Jesse many years ago (probably 15 or so), so I have no idea if it is the same as the Dynojet needle. Perhaps someone else knows? As to your interpretation of my use of the phrase "take throttle", yes indeed I meant being able to take opening the throttle (I am married to an English major and, while not quite as dedicated as you, do appreciate the correct use of language....however I only take definitions from the OED for "English" - Websters is for "American English" :) )

    So questions back to you:
    1. I do not have access to a digital tach or a CO meter, I was going by ear and detected virtually no change. I could hook up the stock tach and I assume you would be looking for a change in RPM, even if very slight. My limited experience with fuel screws or air screws is that there is a marked change in engine speed when you get too far from ideal which is what I expected here. Should I be looking for a very subtle difference?
    2. If the thought is that I am lean at those low throttle openings, should I try a 40 pilot?
    3. I have the stock Canadian needle... a 5DC56. Should I go back to that?
  14. motolab

    motolab Long timer

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    I did?
    That sounds like a lean condition.
    The idle mixture screw on a BST-series carburetors is a fuel screw (there is no such thing as a "fuel air screw"). That said, how was the setting arrived at?

    Regards,

    Derek
  15. motolab

    motolab Long timer

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    Does it have five clip positions, or six? Is it made of aluminum, or stainless?
    Is the OED definition in this case different from the Websters?
    That can be remedied.
    Yes, but the original stock tach may not provide sufficient resolution.
    Yes.
    It is very unusual to require a different pilot jet size than stock, so there is likely to be another cause that should be identified and addressed.

    Regards,

    Derek
  16. afordableperformance

    afordableperformance Been here awhile

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    To me this sounds like the pilot circuit is not clean, possibly in the carb body if not the jet. With the 3x3 airbox I would keep the Jesse needle in the middle and the genuine 135 main. I do have a 40 pilot in mine but with the fuel screw being adjustable I don't think there's enough difference between a 37.5 and 40 to worry about it especially if you have no change when turning the screw, that makes me believe something else is not flowing properly.

    Just a thought, are you still running the vacuum petcock, maybe acting up. Try plugging the port on the carb and running the petcock on Prime and see if there's any difference, I hate those vacuum petcocks!
    TxGhostrider likes this.
  17. afordableperformance

    afordableperformance Been here awhile

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    Are you running a Vacuum petcock? That's the only place I can think of above the float bowl that could be a fuel source, try what I said in the post above, plug the port on the carb and run the petcock on Prime if you want to ride it.
  18. MrPulldown

    MrPulldown Long timer

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    Do you let the bike warm up before this "touch throttle dying". In stock form these machines are warm blooded beast. THe 94+ are tuned super lean and need to be fully warmed before it will take any throttle.

    Spend some time learning some basic carb tuning theory. Assume you have a cut air box. If you cover 60% of the opening then you get less air into the carb. Less air same amount of gas (not exactly but since the carb setting/jetting is the same, close enough) means you "richen" up the mixer. Rich running better means you need to richen up the mix with the current air box configuration (no covering 60%). This means you are currently super lean. I forget all the history/details. Chances are you have a clog somewhere that is limiting fuel.
  19. markk900

    markk900 Been here awhile

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    Vacuum petcock not in use: I have an Acerbis 16l tank on. And the pilot circuit is good - last winter it went through a soak, blow out with compressed air, and it has a new 37.5 pilot installed. As Derek (@motolab ) points out the fuel screw impact is subtle; I will pursue the correct fuel screw setting. And I should emphasize, the surge I am talking about is very minor - I can just detect it when cruising along with almost no load on the engine and very little throttle. Thanks for the thoughts though.

    On a related note: does anyone know what the output of the tach signal wire looks like (white/red from CDI box)? I have access to a both an oscilliscope and a frequency counter so thought I could rig up a digital tach for the purposes of troubleshooting. I can just hook up and look but might not be able to see the correlation between revs and signal.
  20. Alaska1WD

    Alaska1WD Long timer

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    Another compatibility post!

    Sending an Eiger spring to a forum guy today. It's the little spring that goes on the auto-decompression part of the camshaft. Here is the comparison picture. The DR has a 10 coil spring and the Eiger has an 8 coil. Same length, but the Eiger spring seems to be stiffer and have less slack too. Not sure it's a lot of difference, but it seems like a good upgrade if your top end is taken off anyway. Any other suggestions for me to compare for compatibility and options?

    [​IMG]
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