748 Bad Day For Me And My 748r :-(

Discussion in '748 / 916 / 996 / 998' started by TelRobinson, Feb 9, 2019.

  1. As soon as I’ve got it all off, I’m going to give him a shout. Would help me out no end!!

    Bargain lol! I’m glad I didn’t end up with a boring, cost effective bike :joy:
     
    • Funny Funny x 1
  2. I’ve now got the head off which came with the barrel. Looks like both inlet valves are chipped and exhaust valves must be bent as I cant turn the cam. Good news is, other than needing a bloody good clean, the piston looks fine.

    Not ideal, but at least I’ve got a starting point.

    F76B6248-74D6-4A45-8694-1ADAE545474F.jpeg

    93C1691C-F86B-4342-A39B-EDCA4B925CBF.jpeg

    FB9C26CB-8FB0-4E5D-980C-C134116FC130.jpeg

    FB637520-60DF-4CC4-9738-B3BF12E06420.jpeg
     
  3. Can see on piston crown where the inlets have hit but those Exhaust valves looked burnt.
     
  4. Parts list show the following Inlet Valve fitments...



    21010222A
    INTAKE VALVE Part Diagram 2006 Monster
    Monster S4R
    21010222A
    INTAKE VALVE Part Diagram 2005 Monster
    Monster S4R
    21010222A
    INTAKE VALVE Part Diagram 2004 Monster
    Monster S4R
    21010222A
    INTAKE VALVE Part Diagram 2003 Monster
    Monster S4R
    21010222A
    INTAKE VALVE Part Diagram 2002 Superbike
    748 R
    21010222A
    INTAKE VALVE Part Diagram 2001 Superbike
    748 R
    21010222A
    INTAKE VALVE Part Diagram 2001 Superbike
    996
    21010222A
    INTAKE VALVE Part Diagram 2001 Superbike
    996 S
    21010222A
    INTAKE VALVE Part Diagram 2001 Superbike
    996 S
    21010222A
    INTAKE VALVE Part Diagram 2005 Sport-touring
    ST4 S
    21010222A
    INTAKE VALVE Part Diagram 2005 Sport-touring
    ST4 S ABS
    21010222A
    INTAKE VALVE Part Diagram 2004 Sport-touring
    ST4 S
    21010222A
    INTAKE VALVE Part Diagram 2004 Sport-touring
    ST4 S ABS
    21010222A
    INTAKE VALVE Part Diagram 2003 Sport-touring
    ST4 S
    21010222A
    INTAKE VALVE Part Diagram 2003 Sport-touring
    ST4 S ABS
    21010222A
    INTAKE VALVE Part Diagram 2002 Sport-touring
    ST4 S
    21010222A
    INTAKE VALVE Part Diagram 2001 Sport-touring
    ST4 S
     
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  5. with the mechanical interface of valve to piston other things to consider might be rods and or crank are they damaged or bent?
     
    • Funny Funny x 1
  6. ^ not a chance.
    They will be fine
     
    • Agree Agree x 1
  7. I have had engines where the valves hit which has broken the edge of the piston crown & squashed the top ring. But usually not. Only time I have seen bent conrods is with Hydraulic compression caused by water & from too much Nitrous in a dragster we looked after.
     
    • Agree Agree x 1
  8. While the rods may not be bent, if the valves have had a good clattering I would be checking the bottom end bearing for that rod.
    But remember, as it's an 'R', the rod bolts have a different tightening method to normal ones.
     
  9. As referred to previously this is the relevant page from the 2000 748R workshop manual, with each step having it's own procedure described. There is a similar, although shorter section for reassembly. Let me know if you want any particular sections. Torque numbers are included after reassembly also.

    2000 748R Engine Disassembly.jpg
     
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  10. It's the exhaust valves not the inlets that are damaged in pictures included, together with corresponding damage on exhaust relief pockets on piston.
     
    • Agree Agree x 3
  11. Inlets are chipped :thinkingface:
     
    • Funny Funny x 1
    • Disagree Disagree x 1
  12. I should stick to starter cables and belts love
     
    • Funny Funny x 4
    • Drama Queen Drama Queen x 1
  13. The one (large) inlet valve looks like it has age related wear whilst the other inlet looks in reasonable condition for the mileage. The (small) exhaust valves are well foobarred. Andy
     
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  14. As Chris says, the exhaust valves are the smaller ones, inlet need larger valves to let the volume of air in, the exhaust valves are smaller because the air is forced out by compression.
     
    • Agree Agree x 1
  15. I read up there dudette, I'll stick to wimmin :kissing_heart: u far too bitchy
     
    • Funny Funny x 1
  16. Tel, be careful not to damage your piston rings now that the piston is loose. Definitely two exhaust valves needed, you'll know more about the inlets when they're out and cleaned up.
    Good luck.
    Steve
     
    • Like Like x 1
  17. This is beyond me now mate, next stage is to find someone to do the rest for me as my time is about to get swallowed up by work.
    At least if I source the parts, I’m half way there
     
    • Agree Agree x 2
    • Like Like x 1
  18. Good luck with it and well done for giving it a good go up to now
     
    • Agree Agree x 2
  19. ^ as Carl said, well done Tel :upyeah:
     
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  20. I was sitting here thinking the easy part is getting something apart , the tricky bit is putting it back together properly and reliably .
    At least the op figured that out quite quickly themselves.
    Good luck with getting it back together and finding the right person to do it
    Only trouble now is finding that person.
    Cheers puddy :)