neonsurge Posted January 22, 2006 Report Share Posted January 22, 2006 After 20 minutes riding on Saturday, my '03 Rev-3 suddenly started to run choppily then suddenly backfired and died. Kicking resulted in more backfires so I pushed it back to the van and did all the usual stuff (carb off, checked and cleaned, new plug, check filter and airbox for water etc. etc.) but as far as the life-ometer was concerned, she was reading a big fat zero. Back at the ranch I pulled the flywheel and found that the woodruff key had sheared (makes sense given the symptoms I guess) and that the lower section had fused itself into the crankshaft recess. I managed to pry the offending lump of shrapnel out but while doing so, noticed a very slight amount of play in the shaft (around 0.25mm at the end) - almost unnoticeable but definitely present. I'd always believed that the crankshaft shouldn't move at all - am I right or is a very small amount of play nothing to worry about? I'm willing to have a crack at most mechanical jobs but the idea of splitting the cases to replace the main bearing scares the cr*p out of me! All advice/comments gratefully received as always! Quote Link to comment Share on other sites More sharing options...
scrappington Posted January 22, 2006 Report Share Posted January 22, 2006 Exactly the same thing happened to my 290 Sherco although it was just a woodruff key replacement. Where is the play is it up and down / side to side if you have a problem send me a message as i live quite near you i was also up low north on saturday ( lots of coincidences) Quote Link to comment Share on other sites More sharing options...
neonsurge Posted January 22, 2006 Author Report Share Posted January 22, 2006 Small world, huh? The play is lateral although like I said, very slight. I think that unless someone posts anything along the lines of "whoooooah there dude, you gotta get that sucker sorted out else you're gonna trash the engine!" I'm just going to pay a visit to Mr. Bird tomorrow, stick a new key in there and chuck 'er back together. I've been thinking of following Heath's lead and hunting around for a nice '05 anyway... Thanks for the offer tho, and if I manage to trash it completely you can bet I'll be in touch! Say "hi" the next time you're up at the camp (next Saturday for me, all being well). Big bloke, white van, '03 Beta, chucking myself things that are way above my ability (fun, but it huuuuurts!) Quote Link to comment Share on other sites More sharing options...
gasgas Posted January 22, 2006 Report Share Posted January 22, 2006 (edited) Neonsurge, although the consensus is no play shld be felt, i can speak out of experience that it is possible to feel play when the there is a slipfit on either the crankjournals and/or cases.With a pressfit you have to be very sentive(like i am) to still feel play, but it is there undetected. When you have fixed the woodruff key and the engine is running see if you have any abnormall behavior. Rev the engine and chop throttle that will give you a good feel if there is anything wrong with the bearings. When you have done all the normall maintenance and never found any sand or such thing behind the filter it is virtual impossible to wreck the mainbearings. Not with a low revving trialsbike anyway. So just check its behavior after you fixed it. Is it still feeling good or not? Edit: ha i was just a little too late with my reply i see. Edited January 22, 2006 by gasgas Quote Link to comment Share on other sites More sharing options...
paul w Posted January 22, 2006 Report Share Posted January 22, 2006 (edited) sorry to say that there should be no movement in the mains at all ,up and down, hovever slight. its not that major a job really, although i havent done a beta, 200 two stroke ktms normally take about 5-6 hours for the complete job. engine in and out included. Edited January 22, 2006 by paul w Quote Link to comment Share on other sites More sharing options...
charliechitlins Posted January 23, 2006 Report Share Posted January 23, 2006 I think he said the play is "lateral" which means "side-to-side" to me, and I think a bit of that is acceptable. Quote Link to comment Share on other sites More sharing options...
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