BHB's First XR600R + Winter Rebuild

Discussion in 'Thumpers' started by Brauhausbier, Jan 2, 2011.

  1. Brauhausbier

    Brauhausbier Focused

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    Alright! I'm just about out of here and should be out in HR by 6pm if the traffic doesn't totally suck.

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    Thanks again TourPros!:beer
  2. TourPros

    TourPros Local wherever I go

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    Cam was 180 out which doesn't matter since cam chain is not on lower sprocket but rather wedged in the groove beside it.
  3. Blakebird

    Blakebird Solo Backwardo

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    that'll make a difference :lol3
  4. Señor Squirrel

    Señor Squirrel AKA TTDave

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    Hey TourPro's another late night XR rebuilding event!!! Hope you guys get it fired up tonight!!! :clap

    P.S. Is my chair still in the shop!!!:freaky
  5. TourPros

    TourPros Local wherever I go

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    Chair is still here waiting for ya. Shop is drywalled, insulated, warm, tunes are going and beer is in the fridge. And oh yeah there is a 650 you have to tell me that you don't want.
  6. TourPros

    TourPros Local wherever I go

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    defeated:baldy

    So found the timing out most likely caused by the cam chain not being on the lower sprocket but instead wedged into the groove between the case and the sprocket (Small amount of metal shaving around the area but should be fine after a couple of flushes). But after getting all that sorted out no fire. When I primed it we got a couple of pops and it wanted to but nada. Then tried something a little different. Almost seems to be having an intake issue like no fuel. After adjusting the valves 3 times still just an occasional back fire.
  7. Brauhausbier

    Brauhausbier Focused

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    Thanks so much TourPros for all the wrenching help and the wonderful dinner:thumb

    Glad we were able to solve those larger issues:lol3 That was awesome.

    I just ran the scenario from last night by my co-worker who's a former auto mech. He might stop by tonight and check it out. He had a couple of suggestions.

    - pull carb and pull intake boot off head, and place hand over while kicking to verify suction (I think taking a look down the intake is a good idea)

    - spray starter fluid directly in the intake (carb out)

    I think at the end of the night it was obvious we had good spark, but no fuel getting into the cylinder no matter if the valves were all the way loose or too tight. It seems like there is a wall over the intake side or an obstruction?

    We had a couple of good backfires that did blow WD40 that we had sprayed down the spark plug hole out into the airbox.

    I'll give her another look tonight. Thanks so much again TourPros:freaky

    I'm not sure how I'm awake after only 4 hours of sleep - got home at 2:30am - XR Fever:lol3
  8. Luke

    Luke GPoET&P

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    I keep hearing this. Would you mind explaining how this is possible on this bike? I always figured that if you're on TDC and it turns out to be the exhaust stroke, just rotate the crank 360 and it will be TDC on compression. There are no other cylinders or cams or points to syncronize with.
  9. Luke

    Luke GPoET&P

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    Was it off by 180, or by some other amount? It looked right before we started kicking the other day (checked the flywheel and sprocket marks) If it was some other amount then the cam chain must have slipped and it's time to check for bent valves.
  10. mcma111

    mcma111 Long timer

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    The cam timing was out because he had the cam chain OFF of the drive gear. It was getting rotated by friction alone.
  11. MortimerSickle

    MortimerSickle Semi-Adventurer

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    Wouldn't 180 out mean having the cam positioned for TDC, when the crank is at BDC?
  12. Luke

    Luke GPoET&P

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    As it was insisted to me, it meant that the cam was off by 180- which would be 360 at the crank. Which is where I get confused.
  13. Brauhausbier

    Brauhausbier Focused

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    Thanks so much for the tips via the phone mcma111!:clap:clap

    Back to the drawing board tonight! Thanks for sending up an OE cam:thumb
  14. Luke

    Luke GPoET&P

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    Not exactly, I don't think. I watched the cam rotate while rotating the crank and it stayed in register, so the pins on the outside of the cam chain were probably catching the lower sprocket. It would have lost timing if the engine ever started, for sure, though. A good kick could have done the same too.

    My point regarding the 180 timing is that it doesn't matter if the cam is off by 180 or not when you assemble it. If it is you just need to give the crank a full turn before installing the valve cover and adjusting the valves. Is this not true?
  15. MortimerSickle

    MortimerSickle Semi-Adventurer

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    I guess I am confused too. I was thinking of it being off by 180 crank degrees... but I guess that would be only 90 cam degrees. :yikes Crap, I think my brain just skipped a cog. :D
  16. TourPros

    TourPros Local wherever I go

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    Cam was off as chain was constantly slipping. While it did turn everything when cranking the engine and did when kicking it over it was also slipping. The chain was wedged in tight to the groove between case wall and sprocket. As for degree of cam I guess you would be right aboutnot being full 180 out but book clearly calls for cam to be lobes down at TDC and lines flat with top of head.
  17. canyncarvr

    canyncarvr Adventurer

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    It matters if it's an interference engine. In such a situation you want to avoid ANY unsynchronized cam/crank movement to keep from damaging the valves and/or the piston. As a matter of safe assembly practice, ALways sync/align the camshaft/valves to crank position when you're putting an engine together.

    Oh...it does NOT matter if the cam is off by 1/2 (one crank revolution) if you are working with a distributor setup. You can just re-place the distributor 180º.

    If the engine (any engine) is assembled in the #1 TDC FIRE position and the other components match that state, you're good.

    The crank doesn't care if it's at TDC exhaust or TDC compression.

    The cam can be 'off' by 180º..and therefore off by 360º of crank. Remember there are 720º to crank movement for one engine cycle.


    Valve lash changes as noted aren't likely to matter when it comes to starting. Certainly they should be 'correct', set to spec..but a fraction of a mm difference in lash and the timing changes that brings about won't keep the bike from starting.

    You know it's right (NOT 180º out) when at TDC compression ALL valves are closed (what TourPros said). Another way of checking that you are at the CORRECT crank TDC with the cam is that, as the crank approaches TDC compression, the intakes have just closed.
  18. crazybrit

    crazybrit Long timer

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    Eric, sorry to hear you're having problems. Keep the faith. On the positive side it looks spectacular in the above pic. Damn!
  19. Luke

    Luke GPoET&P

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    Yes, and since the timing chain was slipping I would now start checking for bent valves.


    Agreed again. The reason I started banging the 180 drum is this: If you go to adjust the valves and find that the cam is off 180 when at TDC, you don't need to re-time the cam. You just rotate the crank another 360 and the cam will be in the correct position.
  20. Brauhausbier

    Brauhausbier Focused

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    I just got off the horn with mcma111. I'm going to take off the head and do a leak test on the valves. Will be a good chance to check all those valves out and re-do the cam timing again.:lol3

    I can re-use the head gasket (just a bit more torque) and might as well get some new crush rings for the exhaust. Looks like I'll get a OE cam to play with next week, but I'll see if we can get her started with the hot cam.

    You racing this weekend Luke? Want to help with the top end tear down and re-assembly?:evil