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My First Engine Rebuild :)

Discussion in 'Maintenance and Servicing' at netrider.net.au started by slideways, Feb 26, 2013.

  1. So middle of last year, I was at the track, flying down the straight when all of a sudden I lost power. The engine sounded really funny, and had a really weird vibration. I limped back to the pits to check it out. Started it again to have a listen. The engine was rattling and wobbling, my day was done.

    I've only done the basics on a bike, oil/coolant, bleed brakes that sort of stuff, so I had no idea what was wrong with the engine. I actually thought it had dropped a valve or something. I booked it into a bike mechanic for them to have a listen. They poked around at a few things, checked the timing etc. But told me it was something in the bottom end of the engine, and would likely need a rebuild. I asked how much.... around $2 – 3000 was the response.

    Considering I only paid $2k for the bike, It wasn’t worth it. So the bike just sat there for a few months while I decided what to do. I have a complete service manual, and my dad owns a workshop which was going to be vacant for nearly a month over xmas. I was on holidays, So I thought, I'll just rebuild it myself! I've got nothing to lose.)

    So with not much mechanical experience with bikes, with a friend to help with the heavy lifting. I got started.
    It was surprisingly easy to get the engine out of the bike, taking photos of everything as I went, marking all the plugs with coloured tape, and using labelled zip lock bags, I had the engine out of the bike in one afternoon.

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    Then following the service manual step by step, managed to separate the crankcases. And I found the problem. It had “spun a bearing” a new term I have just learned. Not only did it spin the bearing, it had worn the crankshaft beyond its service limit.

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  2. Looking all over ebay, surprisingly, in the UK, I managed to find a crankshaft from a newer bike in extremely good condition for only $150. (postage was another $150)
    For new bearings, conrod bolts and gaskets etc was about $400 (from the dealer)

    While I waited for parts to arrive I decided that I would take the whole bike apart and give it a clean.

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    Once I had all the parts, and studied the service manual many times, I put the new crankshaft in, Plstiguaged the clearances, and put the whole engine back together, over a couple weekends. Checked the timing about a hundred times. And in another afternoon put the engine back into the bike. Followed my photos of the wiring, and plugged everything back where it was before, then filled it with oil and coolant.

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    After I had everything done I was sure that I must have made a mistake somewhere, and there was no way it would start.. you wouldn’t believe the elation I felt when she fired into life! Unbelievable! Took it for a quick blast up the road and back to check everything, and surprisingly it all felt awesome!

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    1 week later (yesterday) I got to take her back to the track after many months away, and do what I love most!

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    In the end I saved about $2k worth of labour, and learned so much about bikes and engines. And now feel confident doing any sort of service work on my bikes:) If anyone in Brisbane ever needs help rebuilding an engine. I might be able to help you :)
     
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  3. Good work! Doing things yourself is great and you learn a hell of a lot in the process. Well done :). Gives me some inspiration to clean my race bike, it is a bit filthy sitting there for a year and a bit now!
     
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  4. Hats off to you!!!! Reckon it would have been a very satisfying project!
     
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  5. FANTASTIC, I LOVE reading stuff like this. Not only did you save money on the rebuild, you did a whole heap of stuff that someone else doing just the rebuild, wouldn't have done. A BIG congratulations!!!
     
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  6. Well done mate. :D


    Almost given me the inspiration to get off my arse and put mine back together..
     
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  7. congrats man. might be a bit late to the thread but still a good on ya :)

    i just went down to an older bike... 94 zx9r cheap... with 75k on it, aim in the same boat.. never more than coolant and oil. thinking of rebuilding in a few months as a project. its great to hear that someone in a similar boat happily and accurately got the job done.
     
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  8. Great stuff, i am doing the same thing with my 92 cb750 , need to drop the crank to replace alternator drive chain & tenssioner so doing a whole bottom end rebuild while it's apart, bike cost $1100, getting work done professionally $2000-$3000 , do it myself $600 in parts
     
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  9. Good write up I'd love to get to this level one day
     
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