andy_290 Posted May 2, 2005 Report Share Posted May 2, 2005 Hi All, Having problems with my 02 Beta at the mo, the bottom end of the rev range is sweet as a nut, top end, there's some missing, pinking under throttle and a sharp tapping/knocking sound when coming back off it. Think I'm gonna have to take it in to be professionally looked at. Anyone know what these symptoms are leading towards and how much people like Lampkins charge for repairs and or servicing? Many Thanks Andy Quote Link to comment Share on other sites More sharing options...
Guest coflet Posted May 2, 2005 Report Share Posted May 2, 2005 I had a very similar problem with my 03 rev 3 250 turned out to be the electric fan switch not coming in therefore it was getting to hot and running crap new switch it was ok, Albeit the bike was 2 weeks old when the fault occured (didnt suspect a new switch to be faulty)!. The new switch cost about Quote Link to comment Share on other sites More sharing options...
andy_290 Posted May 2, 2005 Author Report Share Posted May 2, 2005 Next door neighbour's cleaned out the carb, I changed the plug and the air filter. the fan came on while we were looking at it, we've taken the flywheel cover and removed the moisture from the cover, and also sprayed wd40 on the coil. My dad reckons the tapping noise is piston slap, but I don't know!?!? Quote Link to comment Share on other sites More sharing options...
Guest coflet Posted May 2, 2005 Report Share Posted May 2, 2005 If there is a bit of slap at the fop end you will have to take the head and barrel off and check the barrel with a piston ring in the bore then check the ring gap also look at the bore and see if it has a protruding lip at the top of the bore .You may be able to re ring the existing piston if the bore is ok (not scored) Quote Link to comment Share on other sites More sharing options...
booma Posted May 2, 2005 Report Share Posted May 2, 2005 had a similar problem with my rev3 03 model, turn out to be the woodruff key had sheared causing the timing to slip, as you have the flywheel cover off ring your nearest trials repair shop to see if the have a flywheel extractor its only a 5 minute job and should cost very little hope this helps good luck Quote Link to comment Share on other sites More sharing options...
j@mes Posted May 2, 2005 Report Share Posted May 2, 2005 could be carb set up wrong or not good enough fuel being used. Quote Link to comment Share on other sites More sharing options...
andy_290 Posted May 2, 2005 Author Report Share Posted May 2, 2005 Yeah next door neighbour is a mechanic, been riding/fixing them for literally 30 odd years, but he's mainly into pre-65 stuff. It's got Optimax in with the oil at 70:1 Quote Link to comment Share on other sites More sharing options...
neonsurge Posted May 2, 2005 Report Share Posted May 2, 2005 If you do a search on this forum, you'll find that engine knocking both during hard acceleration and when rolling off from full throttle is a fairly common problem on '02 and '03 Rev-3s (it doesn't seem to affect earlier or later bikes as much...no idea why.) Try a higher octane fuel - Shell Optimax or other super unleaded if you can get it. That usually improves things but in some cases (like mine!), doesn't cure it completely. What finally sorted it for me was going up a size on the pilot jet from 30 to 32.5 and setting the carb up properly according to the procedure outlined in the Mikuni VM-series tuning manual (which can be downloaded from Mikuni's web site or drop me a PM and I'll email you a copy). If you need to buy jets, I recommend Mikuni/Keihin specialists Allen's Performance. If you're still having problems after that and you're unsure of the history of the bike, take a look at the timing. Remove the flywheel (good opportunity to check the woodruff key at the same time) and look at the stator plate. If the adjuster screws are right in the middle of their slots, the timing's pretty much where it should be and probably doesn't need adjusting. If the timing's obviously advanced or retarded, it's probably worth getting it set properly using a guage or strobe. Good luck! Quote Link to comment Share on other sites More sharing options...
manz Posted May 3, 2005 Report Share Posted May 3, 2005 This is also a problem with the 2001 rev3.. The compression ratio is too high on theese bikes, or the cdi advances too much. Acctually all betas detonate. Even new 05's. Solution? Higher octane fuel. A little richer jetting. Oh, And trials bikes tend to clog up. Try running on a (closed) road, highest gear, full throttle (dont overrev though, and stop if it knocks wery much). Until the engine gets hot. (or open up the cylinder head and clean ) If the bike doesnt run at all when pumpin the throttle (ie, unrideable), the its probably the CDI-Unit which is toast. Quote Link to comment Share on other sites More sharing options...
ricksta Posted May 3, 2005 Report Share Posted May 3, 2005 go 2 lampkins or ring him then u will no exactly whats wrong n what u need 2 do. Quote Link to comment Share on other sites More sharing options...
andy_290 Posted May 6, 2005 Author Report Share Posted May 6, 2005 Cheers chaps, I'll take the flywheel off this weekend, what does the woodruff key look like? Andy Quote Link to comment Share on other sites More sharing options...
neonsurge Posted May 6, 2005 Report Share Posted May 6, 2005 It's a little piece of metal that sits in a slot in the shaft that the flywheel is on and locates into a corresponding slot on the flywheel to prevent it from rotating on the shaft. Quote Link to comment Share on other sites More sharing options...
andy_290 Posted May 6, 2005 Author Report Share Posted May 6, 2005 Cheers pal Quote Link to comment Share on other sites More sharing options...
brian r Posted May 6, 2005 Report Share Posted May 6, 2005 We used to call them a half moon key. That's what they look like. Quote Link to comment Share on other sites More sharing options...
andy_290 Posted June 30, 2005 Author Report Share Posted June 30, 2005 Just thought I'd update this thread, turned out to be the CDi unit that had gone tits up just as Manz thought. Took it up to Lampkins and dropped it off yesterday afternoon, they had it ready for me by lunchtime today, top marks for service from John and Gary! Quote Link to comment Share on other sites More sharing options...
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