1997 Honda 300ex not shifting need help

[redhosser]

Got a 1997 Honda 300ex came to me in pieces everything was there I put it back together with a manual. But now it won’t shift, when u try to move shifter it’s like a half click no engagement. I’ve took it apart many times can’t find nothing wrong really need some help. Thanks

[Gwbarm]

Sounds like the linkage is not engaging fully, did you put all that back together or was it alredy together.

[redhosser]

Linkage was already together I think it’s something to do with the shift drum. With the case split and turning shift drum it seems to be working all the forks move and engage. Put the case together and that’s when it seems to lock up.

[Gwbarm]

That’s good it no in the trans. Check the linkage connection to the shift drum it could be one of the engagement pins is missing or the linkage is not in correct position on the drum to turn it.not sure on yours but some have springs that hold them in place that take missing

[redhosser]

This is setup I have and everything appears to be in right

[Gwbarm]

When you pull up on the shifter does it engage the linkage and move the shift drum.

[redhosser]

only turns in maybe a quarter not enough to engage a gear

[Gwbarm]

That does sound like the linkage is either not in the right position or not engaging the drum properly, inspect both drum and linkage for damage.

[Mech]

In post 33 you say it was moving the shift forks when the cases were apart.. that was the center cases that were apart ? And then it locked up when you put the cases together and bolted them up.. Have you/did you try the shifting with the bolts backed off a bit ?  It sounds like the center cases have no end float on one shaft..

[Mech]

I can't make out the photos..

I'd try holding that spring loaded roller off a little and turn the shift drum by hand, while rotating one or both gear shafts, and make sure the shift barrel/drum and forks and cogs are all moving, in case something is being pinched by the cases, then I'd work on/look at the linkages.

[redhosser]

With left and right case split you can rotate the drum and shift forks move and engage as should. Put them together and it’s like it locks up after u put the retainers on that house drum bearing in. If you leave retainers off you can off you can move it but it pushes bearing out

[Gwbarm]

Thats good your transmission is working properly, it sounds like you have figured out the problem, im not sure why that is happening, cant really tell anything from the photos. It sounds like something is too tight in there and not lined up properly.

[Mech]

Ok.. well I can't think of anything specific that would cause that but it sounds like you've narrowed it right down.. I presume you mean the barrel that shifts the forks is seizing up once it's retainer is done up ?  You can check that just by trying to turn it with a pair of slip-joint pliers. See how much you need to loosen it's retainer off to get it free and moving. If that has a ball bearing, perhaps the bearing is the wrong one for the job. Bearings come in different widths and that is probably meant to be a thin one. Other than that, if loosening the bolts is enough to free things up then it would seem it only needs something like a shim, or a gasket to make it right again, so check the parts book for any thin shim/washer/gasket that's missing. Then.. if nothing in the side case is causing it, It might be a shift fork in wrong ? Would those be possible to muddle ? Some are and some are well marked or designed so they can't really be muddled..  Perhaps take the shift barrel's retainer right off and check the barrel for end float. Then fit the retainer again and see what happens. A bit of trying things should reveal what the problem is..

[Gwbarm]

Since you got it in parts you dont know how far the previous owner had it taken apart and how much was put back together or left out. My only suggestion would be get a service manual so you can see if all the parts are where they are supposed to be with none missing.

[redhosser]

Only top end was apart, and I have a one service manual but it’s mostly just diagrams. I had to split case to replace the shaft the chain sprocket rides on. I feel like it’s something simple that I’m over looking. I’ve read that the shifter drum has to go a certain way but I’ve put it in just like the manual says to. The manual makes it sound simple but from the research I’ve read the shift drum has to be timed but no one show how. 

[Gwbarm]

Yeah splitting the cases is always troublesome, things dont go back as easily as they came apart. I would rack my brain and study the diagrams and see if i could come up with what i missed. Dont get discouraged im sure its something simple and the trans is shifting good thats a good sign. When i run into something like this and im not having fun anymore i just have to step back and let it brew for a few days  then get back on it. I know you will figure it out. Nice machine definately worth your time and effort.

[Mech]

Whenever you split the cases it's really important to be absolutely certain the gear shift is operating at every stage of the reassembly. The gears and shift is the one thing that gives people the most trouble in my observations. Don't assume it will change properly once it's together if there seems to be any problem in the early stages of assembly. The gears and the shift\ barrel should all do their thing before the second case even goes on, and they should still all work once the cases are together and tightened. We nearly always have to rotate one or both shafts to get the changes to work, but it should get every gear and that spring loaded roller that presses against the shift barrel's start washer should move the shift barrel once the roller has gone over the top of each of the star washers bumps. It's that roller that moves it into each gear once you have started it moving with the shift lever, and the roller is what stops it vibrating out of gear.

Here's an extract from the honda manual. read it all and look at everything in the diagrams, there are pictures and fine print that explain how the shift lever is meant to engage with the shift barrel.

output.pdf