neonsurge Posted June 6, 2004 Report Share Posted June 6, 2004 After reading all related posts on the subject on this site and having exhausted all other possibilities (carb, cooling, fuel etc.) in an attempt to cure my Rev-3's pinging problem (clarkp's posts have been particuarly helpful - thanks man!) I've finally accepted the fact that I need to investigate the timing. The problem is, this is one job that I've never attempted before and once I get the magneto cover off I'm not really sure what to do next. I guess I need to remove the flywheel to get at the stator (do I need any special tools for this?) but once that's done I'm not sure where to look for the adjuster screws etc. If anyone could point me in the direction of a site that explains the checking/adjusting procedure I'd appreciate it. Or is this something that I should get my dealer to look at? Thanks for your patience. Quote Link to comment Share on other sites More sharing options...
clarkp Posted June 6, 2004 Report Share Posted June 6, 2004 Special tools? - yes, you will need a flywheel puller - get one from your dealer, or contact BETA USA with your credit card in hand - they'll get one to you in short order. And you will need a tool to keep the crank from turning while you tighten the flywheel puller. I use a strap wrench from Klein tools but others will work. I like this type because the strap won't mar the flywheel. I use the S6H - it has enough strap to go around the flywheel. You'll need a strap wrench to tighten the flywheel back on (40 something lb-ft if I remember correctly - ask Commo to be sure). Once the flywheel is off FIND THE WOODRUFF key (little crescent-shaped piece of metal) . It will probably still be in its seat on the crankshaft. Make sure it stays there - take it out and put a little dab of grease in the keyway and re-insert the key, that way it will be less likely to fall out. With the flywheel off you will see three screws that hold the stator plate in place - they are equally spaced around the stator plate. The stator plate itself has slots in it where the screws are to allow timing adjustment. Loosen the screws (you don't have to take them out) and you can adjust the stator clockwise (retard timing - less ping - softer) or counterclockwise (advance timing - more pinging - snappier throttle response). There is a timing hole in the flywheel itself where you can insert a small metal rod (coat hanger, etc.) and it has a matching hole in the stator plate. If I understand it correctly, you would loosen the stator plate, temporarily re-install the flywheel w/o bolting it on - slide the rod through the flywheel and into the timing hole on the stator plate, and use a dial indicator in the spark plug hole to set it at .044 BTDC. I don't remember the numbers exactly - call Commo. The guy I talked to at BETA USA said that if the stator plate is set such that the screws are near the middle of the slots - you are just about right on. Since I don't have a dial indicator, that's what I did and it really helped the pinging. My bike still pings but nothing like before. With the #30 pilot jet, stator plate in the middle, and a 145 main jet (remember my bike is a 250, not a 270) the machine pings only a little under certain conditions. Good luck! Quote Link to comment Share on other sites More sharing options...
neonsurge Posted June 7, 2004 Author Report Share Posted June 7, 2004 OK, with a bit of improvisation I got the flywheel off and checked the timing (the bolt's not reverse-threaded and you don't need to remove the four cross-headed screws - doh!) The screws were adjusted dead in the centre of the slots (factory settings) so I've rotated the stator very slightly clockwise to retard the ignition a bit in an attempt to curb the pinging. As per John Lampkin's recommendation, I also checked the reed block (looked OK) and removed, cleaned, reinstalled and triple-checked the inlet manifold for leaks. I also removed the carb (again) and blasted everything out with compressed air (the jets were clear). Now I just need to get the bike good 'n' hot to see if things are any better. Thanks for everyone's help. Quote Link to comment Share on other sites More sharing options...
neonsurge Posted June 10, 2004 Author Report Share Posted June 10, 2004 That's got it. Retarding the timing by about one degree has eliminated almost all of the knocking - it's still there, but only very occasionally when hard on the throttle uphill. Once again, thanks for all of the suggestions! Quote Link to comment Share on other sites More sharing options...
wayneg Posted June 10, 2004 Report Share Posted June 10, 2004 Be careful not to overtighten the bolts holding the inlet manifold and reed block in place. I did this and suffered major pinging for a while because of an air leak which only happened when there was lots of vibration (higher revs that I should probably be using due to rider incompetance!). The inlet manifold bent a bit because of the overtightening which opened a bit of a gap between it and the reed block which caused the air leak. I have learned from this mistake and won't be so brutal with spanners ever again..... Quote Link to comment Share on other sites More sharing options...
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