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About FallingOff

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  1. FallingOff

    100,000+km DRZ400SM top end

    Thanks for the suggestions. I don't think it's the stator. My original stator was bad and I've replaced it (admittedly cheap Chinese crap which had to be modified to fit properly). Same symptoms with both stators. I also tried running the bike from the battery, with the stator disconnected - no improvement. Oic0's suggestion of a bad coil is worth following up. Anyone think the severely worn cam chain might produce the symptoms? Obviously the timing will be out. What about the marginal ring gap? Could the rings be binding and preventing the motor revving (rather than twisting and breaking)? (If so, why now rather than earlier?).
  2. FallingOff

    100,000+km DRZ400SM top end

    That's a thought. I have a dr650 coil I can swop over. The rev problem happened suddenly and there was lots of backfiring.
  3. FallingOff

    100,000+km DRZ400SM top end

    The ignition coil? Yes, it checks out against the manual specs. I also tried a new ignition lead, in case that was breaking down at higher revs.
  4. FallingOff

    100,000+km DRZ400SM top end

    Agreed, not pretty. I'm leaning towards new valves now. Re the cams: they still look okay. No pitting or scoring, but the flats are showing a brassy colour. The cam height is (just barely) in spec. I think I'll get a few thousand more km from it.
  5. FallingOff

    100,000+km DRZ400SM top end

    Radtech, the cam chain is original, with the auto tensioner. I have a new chain, and a manual tensioner is on order. I will get a new piston, rings and valve seals. I'm not sure the budget extends to new valves and springs. The rings are in spec at the moment and the valves look like they will clean up nicely. I'd hate to spend a lot of money on the top end if the rev problem is electrical or carb related. Thanks for the input.
  6. FallingOff

    100,000+km DRZ400SM top end

    I'm having problems with my 2006 drz (100,000+km commuting miles, bog standard bike) which I've owned from new. I rarely visit the rev limiter and generally treat the bike well. Power suddenly disappeared while riding and the bike won't rev. I think I've discounted the carb. The stator failed and I replaced it with a Chinese cheapo copy. The bike appears to pass all electrical tests, bar the test for 75v max voltage at the stator (I can't get the bike to rev high enough to test this). I've taken off the top end and found some curious things. The cam chain is very worn, judging by the angle of the sprockets - at least 10 degrees off. So I'll replace that. Has anyone got an opinion as to whether this is the cause of the rev problem? I did check that the chain hadn't jumped a tooth, BTW. When removing the exhaust cam I noticed the return spring of the auto decompressor had fallen out of its retaining slot, but maybe I knocked it off on removal? The bore is perfect, cam bearings all good. Inlet valve stems are really cruddy - perhaps an oil seal has failed, allowing oil to seep down the valve. The bike has been an oil user from day one. Compression was good when I checked, 150psi. I can't make sense of the piston ring gaps. Free gap should be 5.5mm and 9.2mm. My free gaps are about 9mm and 11.5mm. In the bore the rings should be 0.5mm. My gaps for first and second ring are 0.2mm and 0.3mm - very tight! It would seem they have been like this since the the bike was assembled! There are two small tails of carbon (about 4mm long) on the underside of the first ring leading away from the gap. Ring flutter here? Piston looks fine, just a bit of soft carbon on the crown. I don't have proper tools to measure the bore, but it seems to be under 90mm diameter. Piston seems a very tight fit in the bore, once it is fully inserted. I can see no compelling reason to change the piston, other than the age of it. No scuffing on the skirts. The grooves seem fine. Ring thickness's are in spec but I will change them. Thanks in advance for any comments or insights.
  7. FallingOff


    Maybe the disk is dished? Is the wear on the pads even, or is the outer edge more worn than the inner edge. The SM disk is very thin and easily distorted. I replaced mine with an EBC which is much thicker more rigid. I think my disk overheated (despite the floating design) which caused the dishing.
  8. FallingOff

    DR650 Fork Brace Worth it?

    The dr will veer to the right if braked when leaned over, due to the single disk twisting the fork. Very noticeably. The superbrace completely removes this tendency. I've the Safari tank on my dr and the brace firms up the steering considerably when the tank is more than half full. All in all a good investment, if not essential.
  9. FallingOff

    Noticeable power at loose end of the spec?

    On the other hand loose valves = accelarated wear to rockers and cams. Stay in the middle.
  10. FallingOff

    Broken choke cable?

    I just fixed my seized cable today. I've the Safari 30L tank fitted so the dr350 lever won't fit. I cut the cable about half way along its length (happily past the corrosion point), then made a loop in the wire at the cut point. I cable tied this to the fuel hose. Pulling on the loop activates the choke.It works fine and cost me nothing. I changed out the spring at the plunger end for a lighter one that prevented the choke snapping shut on its own.
  11. FallingOff

    TM40 Installed

    Thanks, BK. I might just kill two birds...
  12. FallingOff

    TM40 Installed

    Slightly OT, sorry. Is the tm40 compatible with the Safari tank? There are issues with the stock carb and the Safari. The carb has a hard time pulling in fuel when on reserve (there's a hump in the fuel line - sometimes a bubble of air is trapped at the hump). Is this the fuel intake (arrowed)? It looks like it might be rotatable - is it? Getting the intake angle right would help a lot.
  13. FallingOff

    Does anyone have a CDI unit for a 2000 Dr650???

    Try: http://www.ignitech.cz/english/aindex.htm (Your exchange rate is going to be bad though).
  14. FallingOff

    06' DR650 Black Plastic Chainguard-Do I Need It???

    If the bike falls over on your leg, engine still running, you might regret taking that guard off.
  15. FallingOff

    DRZ-SM as a commuter?

    They're fine on hard packed gravel. I have the non-supermoto Distanzias on my sm.