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Starting after Rebuild

Discussion in 'Technical and Troubleshooting Torque' started by WiErD, Feb 16, 2006.

  1. Well ive finaly got the rebuild sored, well i think so anyway, its been prolly 2 months of waiting for bits and pieces but oh well..

    after i put the last piece on and filled it with oil and coolant tried to kick it over and battery was dead.

    so i hooked up the jumper leads and gave it a try, eventually started with about 1/4 throttle and wont rev no matter how much more throttle i give it. ive replaced the fual as it was empty also.

    and if i let go of the throttle it dies :(

    anyone got any ideas? is this gonna be a carbie issue? or something else?
  2. No idea, but I feel for you.

    Hope it's something that's easily fixed.
  3. check yer timing, again, make sure that all hoses to the carbie are on and tight(air leak). if all else fails take carbie off and drop bowls check needle and seat.
  4. Battery has just picked up a surface charge and is not making enough power to give a nice fat spark?
  5. Is it firing on all cylinders? (Carefully check the temperature of each header)

    What work has been done to the bike since it was running well?
  6. Running rich?? how does it go after you shut the fuel off (when it is running)
  7. full suckin air,or sticky needle n seat, bash the carbs with a hammer (lightly)

  8. BASH_HAMMER_LIGHTLY my type of mechanic :p :p :p :p :p :p :p :p
  9. Could be many things....likely cases would be cam timing or fuel. I dont know what sort of motor it is so would be guessing. Most likely is that it has electronic ignition, so that is why cam timing or fuel. If cam timing is correct then check valve clearances. Have you done a compression check? Sounds like a valve is not closing fully, or the overlap of IN and EX is too great. hmmmm

  10. well ive done a fairly big rebuild, well for me anyway :)

    first attempt at anything of this magnitude.

    i spun a big end bearing and basically replaced the crank, all the big end bearing,s cam chain, tensioner, and rings.

    ill have to double check the compression and spark etc.

    and mesure the clearances for the tappet shims again, it does smell like fuel all the time so it is probably running rich. hopefully i have better news tommorow :)
  11. Good to see you back and congrats on having the guts to go for the rebuild

    When the engine is back in the frame leave the plugs out (earthed of course ) and the rocket cover off. during the rebuild you have been laying bulk oil in the bearings and cam lube moly spray over the cams etc and crank motor over until oil is up to the top end (Priming the Galleries and pump ) this gives you the chance of re checking cam timing and valve clearances etc before all the covers are on (inital soft bed in)

    This will show up tight spots etc in engine and give you the chance to see if they can be resolved ie cams bedded in some times they need a tap from a soft hammer to bed in

    Cleaned out the carbies totally and in your case made sure that the pumpers are working and replaced the needles and seats in the carb ? the little rubber point might have cracked. Also have you rechecked the inlet rubbers they may have cracks.

    Go for the big start i would have set the engine to run at 1/4 throttle and run for 5 minutes and then shut down allow too cool off and then restart running at a fast idle and then retuned carbs you might need to re syncronise them as they have been taken off the bike during the rebuild.

    Keep on it should come up how long have you run it for ??
  12. ive run it for less than a minute, time to try all the suggestions, ive got a feeling its the tappets though, gonna recheck them after work today
  13. cleaned and balanced the carbies, tuning to stock, new fuel filter, cleaned fuel lines?

    was it running smooth when it was running?
  14. well i drained the carb bowls today and tested all the sparks, the compression .

    after i put it all back together it finally runs without prompting and revs, but when you rev it it stays high (the rpm that is ) and takes about a minute or so to drop back down

    the throttle cable is returningas soon as i let go of the throttle aswell.

    atleast im getting there..

    anyone know what could cause the revs to stay high for so long ? and it is running smooth
  15. foudn the problem, the carbs and airbox werent secured as tightly as they should have been, was leaking vacuum

    now all i need is a new clutch mechanism and i can ride it!
  16. Well done WiErD - you have my admiration and I expect a few others.

    Hope you enjoy it.

    PS - When did you last bleed the brakes? Done forget to make sure it'll stop as well as it goes - specially if the revs hold up a spell!!