Coupelx Posted October 30, 2011 Report Posted October 30, 2011 A little back story to start: Friday of the bhq ride the bike started to get hard to shift while racing, especially the 2-3 and 3-4 shift. the last race it actually 'spit' it back out of gear on i think the 3-4 shift into a false neutral. it still shifted "ok" just playing on the dunes and stuff. Got it home and after a tear down i found a loose eccentric bolt and a grooved basket either of which could cause this. At this time due to my inability to leave anything alone i installed my 8 plate clutch conversion along with a new clutch and various little bits on the clutch side to make sure nothing was going to rattle loose again. Fast forward to friday Phelps and I went out for a dune ride and it worked good. no problems until we went to the drag strip and i really started to beat on it. If i had let the bike set a bit i could make 2 or 3 almost decent passes before it would start doing the same shit i thought i had fixed. Sometime i could get it to shift if i let completely off the throttle when i shifted (granny shift) or sometimes just letting off the throttle and not using the clutch (hard on shit). but again it was "acceptable" just playing around. This bike also has had the dogs in the transmission cut. The obvious here is a FUBAR shift fork, probably from the eccentric bolt not letting full shifter travel and it jumping out of gear? Just kinda looking for some ideas before i pull the engine. Quote
JustPlainJane Posted October 30, 2011 Report Posted October 30, 2011 I have an idea... Check for rags first Quote
Coupelx Posted October 30, 2011 Author Report Posted October 30, 2011 I have an idea... Check for rags first Quote
RadarRacing Posted October 30, 2011 Report Posted October 30, 2011 I recently had similar problems with mine and i got it fixed with some adjustments , new eccentric as well as shift shaft. If there is any wear at all on the shift shaft replace it , same with the eccentric. With a good shift shaft and eccentric have someone on the left side of the bike shift the bike into the gears and the shift drum should put the spring loaded roller right into the lower valleys on the shift star. If it doesn't "clunk" right into gear and the shift shaft/claw doesn't rotate the drum all the way and put the roller right into the lowest part of the shift star then it will give you problems and false neutrals and potentially break something. Also make sure your eccentric is almost bottomed out and do your adjustments in 2nd gear putting the claw with equal amounts of space above and below the 2 pins. I also like to use loctite on the eccentric if you have it and get the 17mm nut on it pretty tight and use the locking/ bendable washer to hold it tight. Quote
BigRed350x Posted October 30, 2011 Report Posted October 30, 2011 The kicking back out of gear is a sign that your dogs are getting rounded. If you are going to pull everything apart and split the cases, get your gears Under-Cut. You already said that you have your gears side-cut, the next step is to get them under-cut. This locks the gears in place once they are engaged. Do you have a shift-pro? Shift-star mod? Is your shift-shaft modded? Have you done the bearing mod to the end of your shift drum yet? These are all the next logical steps to take if you haven't already done them. I would replace the shift forks and do the above mods if you haven't already done them. Give us a list of all the trans mods you've already done.... Quote
Coupelx Posted October 30, 2011 Author Report Posted October 30, 2011 Other than the gears side cut it has the shift shaft mod and shift star modded. It only spit it out of gear once. its not a repetitive thing an it clunks into gear like its supposed to. I used to be able to ride the hell out of this thing and hot lap it like no ones business. Shifts were fast and smooth. Quote
BigRed350x Posted October 30, 2011 Report Posted October 30, 2011 Other than the gears side cut it has the shift shaft mod and shift star modded. It only spit it out of gear once. its not a repetitive thing an it clunks into gear like its supposed to. I used to be able to ride the hell out of this thing and hot lap it like no ones business. Shifts were fast and smooth. Just because it clunks into gear doesn't mean that your dogs aren't getting worn. I would start with replacing the eccentric bolt AND the big heavy spring on your shift shaft that rides on the eccentric. If either one is worn it will cause problems. Pick up a shift-pro and put it in instead of the stock roller. Re-use the stock heavy spring on the roller if you have a shift star mod. The spring that comes with the shift-pro is usually too soft for most people with a modded shift star. If you are going to split the cases, go ahead and get your gears under-cut. (Make sure you have a good reputable shop do this, not just some random dude with a mill. If the under-cutting is done incorrectly it will put more load on one or two dogs than the other and will make things worse. Just make sure you use someone who knows how to measure and do the under-cutting correctly.) I would also get the end of your drum machined down so you have a bearing on both ends of the drum. - Jared Quote
camatv Posted October 30, 2011 Report Posted October 30, 2011 simple. worn trans dogs, bent shift forks, worn shiftng parts. replace everything. Quote
Coupelx Posted October 31, 2011 Author Report Posted October 31, 2011 well i guess out it comes Quote
RadarRacing Posted October 31, 2011 Report Posted October 31, 2011 That's all good advice. Before you split the cases check the drum and shift shaft stuff like I said. I had what i thought was worn doggs or bent shift forks and it really wasn't. All fixed from shift shaft nodding and adjustment. Quote
Coupelx Posted October 31, 2011 Author Report Posted October 31, 2011 That's all good advice. Before you split the cases check the drum and shift shaft stuff like I said. I had what i thought was worn doggs or bent shift forks and it really wasn't. All fixed from shift shaft nodding and adjustment. Its adjusted and brand new. Ive covered the bases and am out of ideas, hence the reason for the post. Thats what probably started this mess but there is something else wrong now. Quote
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