DR750 & DR800 owners thread

Discussion in 'Thumpers' started by MCmad, Jul 14, 2008.

  1. Resi

    Resi Been here awhile

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  2. Ladder106

    Ladder106 It's a short cut, really

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    I've got the entire SR41 motorcycle. That is what I'm moving the SR43 engine into so I have the 41 CDI and all wiring.

    Thanks for the warning though.

    __________________________

    What I do NOT have is a removable timing chain tensioner.

    The timing chain is very slack and must be adjusted. I thought I'd do this while the engine was on the bench........

    .........but then.....

    The rear bolt that holds the tensioner on unscrewed with great difficulty

    A previous owner used some sort of brown (maybe it's old RED loctite) thread locker on these bolts.

    The (*&$#(*&) FRONT bolt will NOT unscrew. I've finally rounded out the 6mm hexagon for the allen wrench after trying the bolt with my impact driver. I really try NEVER to do this and have a pretty good "feel" for when I'm applying too much torque....not this time.

    I've already tried a bit of gentle heat from a plumpers propane torch (Didn't want to get the oxy/acetylene rig in there....tooo HOT)...but the plastic cushioning material on the tensioner sprocket started to overheat so I gave up on that.

    Prevailing wisdom suggests tapping in an appropriately sized TORX driver and trying again.

    Most warn against the use of screw extractors (and I've personally NOT had good luck with them) since they tend to snap off and then leave a very HARD bit behind right in the center of the bolt......and your next step is to drill off the bolt head.

    If the TORX driver solution does not work, I guess I'll drill the head of the bolt off, remove the chain and tensioner, then try heating the remaining bolt stem and (fingers crossed and a few prayers) turning it out with vice-grips since I should be able to concentrate heat on the offending part with all the other bits out of the way.

    If anyone has any other tips for removing a stripped allen bolt, LETS HEAR THEM.

    I'm not really excited about drilling right inside the engine. I'll place a few small magnets around the area to try to catch any metal bits coming off the screw head...but it's still a bit nerve-racking.

    Wish me luck.........
  3. Ladder106

    Ladder106 It's a short cut, really

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    :clap:clap

    YAY !

    The Torx trick worked.

    Screw is removed and the area cleaned up.

    Red Loctite is evil.....should be thought of as epoxy for threads.
  4. robmoto

    robmoto Long timer

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    Silent hunter, I still havn,t put it on yet, I too bought some parts from Zappa a sr43 rotor and the stator from Bluesman, this was to change the ignition for the motard but just haven,t got to it yet, working on my last bike resto forever :clap.

    Ray why are you taking off the cam chain tensioner anyway, has it a broken spring or something.

    Simon the jets arrived thanks mate.
  5. spen

    spen on my arse

    Joined:
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    sunny ireland
    Just bought a DR 750 in bits ,the guy stipped it to tidy up but had no money ,lifted it and brought it home in the back of the car ,so i"m looking ideas for a rebuild .Colours etc .any thoughts
  6. Resi

    Resi Been here awhile

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    Spen, orange-white like on 1988 models, or a blue frame with yellow bodywork...

    Or... like on 1995 ones a dark british racing green...

    Cheers,
    Lars

    Gesendet mit Tapatalk über Erdfunkstelle Usingen/Taunus
  7. Ladder106

    Ladder106 It's a short cut, really

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    OK....THAT is hard to believe. You still have to do mine, you know.



    Robo,

    It was the balancer chain adjuster that had me using bad language. All is well there now.


    .......except (continued on next post)
  8. Ladder106

    Ladder106 It's a short cut, really

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    .....and yet another question for those of you who have screwed together a few BIG engines.

    I've set my balancer chain timing per the manual. My chain has NO chrome links as the manual stated but I've counted chain pins at least 20 times and am certain that it's set correctly.

    BUT

    When I look at the CAMSHAFT timing and set the CAM so that the two marks on the cam are EXACTLY in line with the top of the cylinder head..

    .....the flywheel mark that should be at the TDC casting on the case

    ....is about 5mm to the left (anti-clockwise) to the mark.


    Now moving the cam one tooth one direction or the other in the cam chain results in these marks being a LOT farther off than I have them right now.


    So, am I just being too crazy and precise with this set-up? Or am I doing something silly again.
  9. Resi

    Resi Been here awhile

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    Ray,

    sometimes the aligning marks do fit exactly. I remember one engine with a slight misalignment, like your' s. If you like I can go to the shed and take a picture with measurement of the balancer chain.

    Cheers,
    Lars


    Gesendet mit Tapatalk über Erdfunkstelle Usingen/Taunus
  10. robmoto

    robmoto Long timer

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    Ray, the line on the camshaft if it is a couple of degrees out thats ok, I put it down to slight wear in the cogs quiet normal nothing to worry about.
    Did you notice that the 2 bolts re ballancer chain adjuster are 2 different lenths, I just had too hellicoil Shane Falcon,s bike because the front one was stripped, I did not drill all the way through the crank cases so the hellicoil would not come out the other side, clever prick arn,t I :lol3.
    Another bike I have worked on a SR/43 had the bolts the wrong way arround and the front one was stripped but with the bolts put in the right holes there was enough good thread left for grab, long bolt went to the front.
  11. Ladder106

    Ladder106 It's a short cut, really

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    Thanks, Lars but not necessary

    Yeah, It was just slightly off. I played with it until I convinced my self that setting the cam either forward or back one tooth would have made it not align at all

    Yep, I noticed that the bolts are longer in the rear since the tensioner bracket is thicker in the rear. I've replaced the bolts with stainless ones of the correct length....thanks for the tip.

    Engine is back together as of this afternoon. I pulled the starter and to check the commutator and clean up the black crud around the back bearing. All is OK there.

    Tomorrow I'll pull out the SR41 engine and put the 43 in it's place. Gee I may even have a functioning motorcycle by the middle of the week.
  12. robmoto

    robmoto Long timer

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    Ray, allso because your 43 engine has a better air cleaner eg larger and 130 main jets, you may have to go down a little bit no bigger than 125 with your 41/42 air cleaner.
    you have a better pipe on the 41 now so 125 will be OK,
  13. Ladder106

    Ladder106 It's a short cut, really

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    Rob,

    I was running the 750 with 800 carbs (with the removable pilot jets).

    I switched over to 135 mains and dropped the needle clip one notch when I added the GSXR can. The bike seemed to run just fine.

    You really think 125s are OK?

    I was thinking about leaving the needle as I had it and dropping to 130s with the DR43 engine. Didn't think about the airbox being smaller than normal for this engine.

    Also....a bloke on the DRbig.info site said that there are two bolts holding down the cylinder head that are LEFT HAND THREAD. Is this true?? Gonna start the 750 tear-down right after the 800 transplant is complete.
  14. robmoto

    robmoto Long timer

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    Ray, 125 mains are plenty big enough on middle slot clip position, the thing is because you are increasing the vacume by adding the extra 50cc in the stroke, and not inlarging the air cleaner it is sucking harder.
    SR42 originally ran 117.5 mains in other words this is what you are doing changing a SR41 to a SR 42 so an increase to 125 is a fair bit anyway.
    Head bols left hand thread there ain,t none and believe it or not I am a left hander :lol3.
  15. Simosez

    Simosez Been here awhile

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    that would be a very strange thing to do. left hand threads should only be found on rotating things to prevent them undoing.
    maybe he was working upsidedown. things can seem backwards when they are upsidedown:huh:lol3
  16. Simosez

    Simosez Been here awhile

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    oh, and thanks for all the replies regarding the starter. it will be good when this bloody dakar race is over so i can get off the f5irehose and do a bit!!
  17. Ladder106

    Ladder106 It's a short cut, really

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    Ahh another one. This year sure looks difficult.

    The first 3 stages woulds squached me flatter than hammered dog poop.

    Was thinking it would almost be too bad to go and actually race this thing (not that I could at my age anymore). Between saving your life and glancing at the roadbook, I'd never have time to appreciate things like 1000 meter dunes running right down to the beach.

    It would be a great place to take a tour and ride some of those routes.

    As long as there was someone there to feed me and a place to lay down after picking the bike up 25 times in the sand.

    Dunno how they do it.
  18. mait

    mait Been here awhile

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    I have removed top end from the engine. What I've found:

    Compression ring - end gap 0.95mm (service limit as per manual = 1mm). Too close to limit.
    2nd ring - end cap 0.45mm (1mm service limit).
    oil ring top rail - end gap 1.80mm :huh that is too much I think?
    oil ring bottom rail - end gap 0.4mm

    Piston manufacturers recommend 2nd ring end gap to be larger than top ring. I've also read recommended oil ring end gaps to be ca 0.4mms.

    Exhaust valves are not tight, one has small leak, the other has excessive leak.

    Camshaft cam heights 0.8 and 0.7mms worn below service limit.

    Rocker arm surfaces are worn.

    Camchain is OK, 20 pitch length 128mms, service limit 129mms.



    I'm afraid Suzuki does not sell +0.5mm oversize rings any more, only complete set with piston. The piston is still fine (cylinder was overhauled 10000kms ago). I've been looking through all piston manufacturers' catalogs but haven't found direct fit rings. There are some 105.5mm sets available but the heighth and width of the rings wouldn't match.

    One more thing I've found when replacing countershaft seal (there was small leak). The inner race of the bearing sits loose on the shaft. I am able to turn it with my fingers while holding the shaft in place. There is no noticable play between the shaft and bearing though. Gonna split the cases and inspect the shaft. Probably bearing glue will do there.

    I have to find out now what to do with the rings and camshaft...

    To cheer things up here is a photo of building exhaust before the engine was taken off. Thanks Resi for the header pipe and thanks Ladder for info on GSXR muffler setup. Sorry for crappy quality pic
    [​IMG]
  19. mait

    mait Been here awhile

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    Just saw the broken fairing and it reminded me how that happened. The friend of mine who took the photos laughed like crazy when we stopped. I had been riding like that maybe a few kilometers without noticing the branch I had picked up from high speed double track in the woods.
    You know how its done - standing on the pegs and looking far forward, pretending you're Marc Coma (or maybe Joan Barreda Bort these days). Thats why I didn't see the branch hanging from the bike before we stopped.

    [​IMG]

    [​IMG]
  20. robmoto

    robmoto Long timer

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    Mait, Just like a Suzuki dealer they HAVE BRANCHES EVERY WHERE.