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About thedktor

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    TT Bronze Member

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  1. thedktor

    DR350se carb question

    Ok that is all good. I can see the needle is quite a lean one ie fat. You could try a very cheap experiment and raise the needle 1-2mm with washers under the clip - I am pretty sure that will help. A needle with grooves has each groove 1mm apart to compare. If you can't find small washers you could make some from some plastic sheet, eg an old oil can.
  2. thedktor

    DR350SE transplant questions

    Wow great job so far. Tell me more about the CDI - is this so you can adjust timing?
  3. thedktor

    DR350se carb question

    Ah you are making us work hard with this one! From your pic it looks like the air jets are correct, the middle one should have a hole about 0.7mm, the right (pilot) should be about a 1mm hole. So, you say you have the white spacer that fits under the needle clip, what about the white spring locator that goes on the other side of the needle clip, on top? We are running out of ideas, next thing is to put a bigger main in, start with a 130. , or raise the needle with a small 1mm thick washer. I have done this with one of mine to fix a similar problem.
  4. thedktor

    DR350se carb question

    OK so its not a question of adjusting the fuel screw so leave that alone for now and make sure all the passages are clear. And I would check the main jet size first as if its too small you will get the same issue. Back to the air jets as per my pic above, the pilot air jet is about 1mm and the main air jet is smaller about 0.7mm, check they are not the wrong way round! They are the opposite size to what you would think logically...
  5. thedktor

    DR350SE transplant questions

    Some back pressure is good, particularly for low and mid-range power. I've done a lot of experiments with different bikes, pipes, and jetting over the years and the results are quite interesting (to me!). Once you reduce silencing to the point where the tone is no longer crisp but more of an unpleasant drone then you lose power in the "usable" range, and sometimes gain a small amount nearer max revs. DB killers are in my experience completely useless devices! Well, they reduce Dbs by restricting flow, ie killing power as well as noise. The best silencers have a certain amount of volume, plus baffles, so the flow is not so much restricted as sent round a few corners and the gas area expanded to reduce noise. Any straight-through pipe does not do this. For example, KTM 4-st silencers use one or two baffles, plus a reasonable volume, plus replaceable wadding and produce a healthy crisp noise and plenty of power. CRD Absolute Performance another good one, The Absolute Power is straight through and too noisy/drony. I have an Arrow silencer on one DR, its OK, perhaps slightly restrictive compared to some but better than stock and not loud by an means. The Supertrap exhaust reduces noise by restricting flow, its a very simple design but not very good if you want power *and* silencing. One of the best exhausts for the DR is one I have that Jesse from Kientec modified to open up the internals and exit hole - its a little louder than stock but not offensive at all, but much more freerer flowing - good power everywhere. That's all, for now
  6. thedktor

    DR350se carb question

    On standard jetting these bikes will run bad if you leave off the airbox side, or chop a hole in the top, so leave all that standard/fitted for now until you have it running properly. Is the diaphragm fitted correctly and not split? What size main jet and pilot?
  7. thedktor

    DR350se carb question

    Typical of being very lean on the needle - have you left out the white plastic spacer that sits under the needle clip? Also did you check the pilot airways were all clear, just blowing air through them won't necessarily clear them. Pilot air jet on the airbox manifold side, - see arrow on pic, its a different carb but same principle. and the middle hole is the main air jet. Blow in the pilot air jet and it needs to come out the pilot jet (in the bowl), the fuel screw (take it out first) and the exit into the carb bore.
  8. thedktor

    DR350SE transplant questions

    That is really cool and I love the engine colour. I hope yuo can find room for the oil tank, 2 litres plus an air gap , I expect the normal DR frame tank has been designed to prevent the oil frothing or at least the flow allows time for the oil to settle enough for air bubbles to be removed.
  9. thedktor

    Photobucket Images

    That is great news, thank you. (and I checked some of my old posts and all good!)
  10. thedktor

    Photobucket Images

    Hi - I have searched but can't see a definitive answer. I have old threads where I used Photobucket links to embed images, which as users know were blocked by PB a while back unless you paid! But I see that TT have done some clever coding to overcome this, great job. What interests me though is whether you have actually dragged the images out of PB into TT or if it is still linking to PB? I want to future-proof my threads and wondering if I should upload the pics or if you have essentially done that for me :) eg https://thumpertalk.com/forums/topic/942713-my-dr350-project-chapter-2-chassis/?tab=comments#comment-9939007 Thanks
  11. thedktor

    DR 350 No compression

    Check the decompressor lever on the cylinder head is "loose" - the cable should have a small amount of free play and the lever on the head should move a few mm freely. Otherwise it will be permanently opening one of the valves. A more serious problem can occur if the engine has been burning oil for a while - carbon can build up on the valve seats and prevent them sealing properly (from experience with one of my DR's).
  12. thedktor

    DR250S still running too rich after carb rebuild...

    Your fuel level is way too high ! You need to check the needle valve and the o-ring the seat sits in. and your float probably.
  13. thedktor

    DR 350se Idle issues

    Check your airbox cover and if its got a gaping hole tape it over to leave about a 2" square hole. That will work with standard jetting - before modding a bike always make sure it runs properly as stock. But I suspect you have a blocked pilot jet anyway, classic symptoms - carb off time I'm afraid.
  14. thedktor

    Jetting Debacle

    As an aside, the CV carb can be made to work pretty good if set up correctly (aftermarket thinner needle with opened airbox). I have two DR's, one with a Keihin FCR pumper which is fabulous, so punchy and responsive, but the CV carb'd DR is very smooth and refined and its top end power is essentially the same!
  15. thedktor

    Jetting Debacle

    Either use the stock needle raised 2mm with washers and the #140 main, or, much better, use the aftermarket needle, clip middle position, and no more than a #130 main. Its no good putting bigger mains in as a stock engine does not breath enough to increase power at high revs. Opening the airbox increases power low and mid range. Anything over 130 main will *lose" top end power as it makes it too rich. Try it!