pops out of gear

[chris6888]

My 83 katana 650 pops out of gear when i shift into second gear was wondering if the was an adjustment i could do without tearing the bike apart.

[akckhim]

If it does it every time you go to second gear then the engagement dogs are worn to the point were they are done. Replacement of gears is only fix. Or just shift past second to third.

[blowerbike]

just have the tranny back cut....no need to purchase gears.
make sure the forks and drum are in good condition.

[chris6888]

what do you mean have the tranny back cut

[blowerbike]

you send both complete shafts to a motorcycle machine shop.
they re-machine the dogs and slots.
this lets the gears engage and hold engagement better than stock.
sometimes they have to weld up certain areas before machining.
john pearson/pearson racing offers this as does many other companies..
APE-MRE ect...

[spchips]

"just have it back cut" means:

-remove the entire engine
-split the cases (heck while you're at it why not redo the top end - but not necessary)
-take out the transmission gears & bring to a machine shop
-They will cut the dogs so the gears will tend to slip into gear, instead of out of gear, under load
-reassemble
-reinstall engine

Definitely represents at least 2 weekends if you're tearing it apart yourself and good luck finding a regular mechanic to do it. Cost is probably not that bad.

[blowerbike]

"just have it back cut" means:

-remove the entire engine
-split the cases (heck while you're at it why not redo the top end - but not necessary)
-take out the transmission gears & bring to a machine shop
-They will cut the dogs so the gears will tend to slip into gear, instead of out of gear, under load
-reassemble
-reinstall engine

Definitely represents at least 2 weekends if you're tearing it apart yourself and good luck finding a regular mechanic to do it. Cost is probably not that bad.

my response was to the gear replacement comment..
i was offering an option plus my suggestion gets him a better shifting motorcycle.
replacing parts with new OEM takes the same amount of labor.
if the OP has a 300 dollar bike then skip all of thee above recommendations and just shift pass 2nd.

[kawfeedave]

what do you mean have the tranny back cut

Motorcycle transmissions use shift 'dogs' on the side of each gear to engage the next gear onto the shaft. Each gear has a set of 'blocks' (dogs) on the side of the gear, arranged around the circumference like the hour numbers on a clock (just not that many). They're spaced so the dogs from the gear next to it can lock in and engage the gear. This is the 'clunk' you hear when shift into first from a stop, is the one gear locking into the next and bringing it up to speed. When you're moving and shifting through higher gears, they are both moving, hence the less 'clunk'.

Anyway, if the corners of the dogs (which are square-ish, like blocks) get worn, then they won't hold the engagement, and the bike will pop out of gear. Back-cutting the gear means that take the square dogs, and cut an angle into them so the leading edge of the dog is 'higher' than the base of the dog, so it holds the engagement better. In order for a dog to pop out on a back cut gear, it would have to slide 'uphill' before it could come off the dog, and when the gear is loaded, it's almost impossible.

The bad news is that you need to split the cases and send the tranny shafts somewhere to have the gears back cut. You could just send the gears, but it's probably better to send the whole thing.

If you don't want to split the cases, either skip second gear, or try to only use it when you're on the gas. The pressure of the load on the gear 'should' hold in place (unless it's really bad) so you can use it to accelerate. If you unload it by letting off the gas in second gear, it will probably pop out of gear.

The problem is mostly found on 2nd gear, and mostly due to poor shifting technique over time. Hard upshifting or 'power' shifting is to blame, and I think 2nd gear is the most popular victim because it's way easier to find a place to slam a 1-2 shift than it is to hit a 2-3 or higher. By the time you get to WOT 2-3 shift on most bikes, you're hauling ass in terms of speed limits and the like, so I think it happen less often. The hard 1-2 probably happens ay every stop light for some squids on a Fiday night ride, so the 2nd gear takes the beating.

The real bitch is that the wear is gradual, and some bonehead PO might wear the dogs down to within an inch of their lives, never know it, and sell the bike. The new owner can be smooth as silk, but eventaully the dogs will give up, and you're stuck splitting your cases or skipping a gear.

[spchips]

my response was to the gear replacement comment..
i was offering an option plus my suggestion gets him a better shifting motorcycle.
replacing parts with new OEM takes the same amount of labor.
if the OP has a 300 dollar bike then skip all of thee above recommendations and just shift pass 2nd.

I understand. I've swapped the gears on my 650 twice. I'm not trying to discourage the poster, just being honest. The first time was a swap from a 20KMi machine, and while it helped, did not solve the problem. The second time was from a much lower miles bike, about 6KMi, and that time it took.

It seems to me this is a very common issue on the GS650's more than other sizes. If you go for a swap definitely try to find a low miles donor.