wild foamy Posted November 15, 2008 Share Posted November 15, 2008 hi everyone. over the last few weeks i have been riding my 1990 DT50MX and occasionally (usually in 3rd/4th gear) when changing up it will just not go into gear but instead stick in a neutral sort of state (disconnected from the final drive, engine free-revving) usually until i repeat the process where it will usually skip the gear altogether. its getting more frequent, on my ride home from work today it did it 3 times (over about 5 miles) and often when i go to park up it wont select neutral and goes straight to 2nd. whats the problem? i dont want to leave it to get any worse as it will no doubt cost me in the long term (i.e. new gearbox) Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 15, 2008 Moderator Share Posted November 15, 2008 If it was just the neutral issue then i would be looking to the detent spring. But with the 3/4th problem as well you could be looking at a worn drum or selectors. Check the obvious like the gear lever is not sticking making you kick it too hard and that the clutch is properly adjusted. Otherwise start saving. You dont want something like this ruining your ireland trip. Link to comment Share on other sites More sharing options...
wild foamy Posted November 15, 2008 Author Share Posted November 15, 2008 clutch was adjusted when i put new levers on it so that seems fine in regard to the detent spring where can i find a new one?, the bike is going for its MOT next week and i would ideally like to get it sorted out as soon as i can. ProBike will probably take 3 weeks to get one in, or longer... also, is there a replacement drum or selector on the market that would fit it? i will pull the side off the gearbox in the morning and have a look-see Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 15, 2008 Moderator Share Posted November 15, 2008 clutch was adjusted when i put new levers on it so that seems fine in regard to the detent spring where can i find a new one?, the bike is going for its MOT next week and i would ideally like to get it sorted out as soon as i can. ProBike will probably take 3 weeks to get one in, or longer... also, is there a replacement drum or selector on the market that would fit it? i will pull the side off the gearbox in the morning and have a look-see The detent spring holds a ball bearing againt the selector drum, there is a recess machined in the drum at the neutral position and when the ball drops into this it holds the drum in position. Its under the neutral switch. As to the selector forks and the selector drum you got to split the cases to have a look at them, Link to comment Share on other sites More sharing options...
wild foamy Posted November 15, 2008 Author Share Posted November 15, 2008 okay, well im taking the bike off the road and will probably pull the whole engine/transmission assembly out of the bike frame so i can get a good idea of what condition the seals e.t.c are in. how do i split the cases? Whilst i'm at it i may aswell do a complete overhaul of the entire bike, im talking new brake shoes, new tyres, new wheel bearings, possibly even a big bore to help cope with the gearing i've put on it (does struggle a bit uphill) Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 15, 2008 Moderator Share Posted November 15, 2008 okay, well im taking the bike off the road and will probably pull the whole engine/transmission assembly out of the bike frame so i can get a good idea of what condition the seals e.t.c are in. how do i split the cases? Whilst i'm at it i may aswell do a complete overhaul of the entire bike, im talking new brake shoes, new tyres, new wheel bearings, possibly even a big bore to help cope with the gearing i've put on it (does struggle a bit uphill) Step one buy a manual Step two read and digest and re read and re digest then take your time. Mate of mine had a dt tuned up further than mine used to do mains reg and could change a crank in a couple of hours . Link to comment Share on other sites More sharing options...
wild foamy Posted November 16, 2008 Author Share Posted November 16, 2008 okay, so assuming i get myself a haynes manual and get the bike apart okay, would i be able to order a new drum and/or selector forks through my local yamaha dealer? (Probike) Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 17, 2008 Moderator Share Posted November 17, 2008 Don't see why not but you might find a good second hand motor a more economical bet rather than spending out on what will undoubtably be expensive parts. Trouble is you wont know the problem till you strip it down or the box really gets bad. Link to comment Share on other sites More sharing options...
Moderator YamaHead Posted November 17, 2008 Moderator Share Posted November 17, 2008 Might just be bent selector forks ......but alas that will require a full tear-down as well. Link to comment Share on other sites More sharing options...
wild foamy Posted November 17, 2008 Author Share Posted November 17, 2008 have taken it out on a spin recently and it was fine, all up and down the box no problem, methink it didnt like the way i was changing gears, i used to syncronise it all so i let off the throttle as i pulled the clutch in and lifted the lever at the same time, now i drop the throttle and pull the clutch in, wait until i have lifted the gear lever to engage the gear and then returned it to the middle position before i let the clutch back in and apply the power. dont know whats happened there then... nevertheless, will pull it out and have a look-see, i dont want to have to stick a whole new lump in as then i have problems with the numbers not matching up on the engine/frame and replacement engines are not easy to find, only ones i have seen are usually incomplete and shagged out Link to comment Share on other sites More sharing options...
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