Offset Cotter Installation

[flyin_]

I was hoping to get some expert advice to verify that my transmission is good to go. Second gear was not engaging enough so I got some offset cotters from Western Hills Honda. I took some measurements and figured I could use a 1mm offset. However, now I'm wondering if my shift drum is allowing too much side play. Here are some photos of the transmission. The first photo is just shifted into 2nd gear (I think this looks good). The next two photos are with the 2nd and 3rd gears pushed as far apart, and together as I can move them with my hands. The next 3 photos are just shifted into neutral, and then with the 2nd and 3rd gears pushed as far apart and together as they will go.

Do I have too much side to side play in the shift drum? If not, do I need to use a smaller offset cotter to keep the gears from ever being able to touch in neutral?

Thanks!

2nd gear


2nd gear pulled together

P1070220 by flyin_, on Flickr
2nd gear pulled apart

P1070221 by flyin_, on Flickr
neutral

P1070224 by flyin_, on Flickr
neutral pushed together-they can just barley touch

P1070223 by flyin_, on Flickr
neutral pulled apart

P1070222 by flyin_, on Flickr
P1070219 by flyin_, on Flickr

[rustywrench]

Flyin,
In my opinion, the cotters were designed to do exactly what you have done.; allow for more dog engagement. Since your fingers will not normally be in there pushing things around, look to see where the gears are positioned when the drum/forks position them. If they engage well and clear well in neutral normally, then you should be fine. Perhaps our more experienced experts may differ, but this has been my experience with these issues. Rusty

[rzgkane]

Flyin,
In my opinion, the cotters were designed to do exactly what you have done.; allow for more dog engagement. Since your fingers will not normally be in there pushing things around, look to see where the gears are positioned when the drum/forks position them. If they engage well and clear well in neutral normally, then you should be fine. Perhaps our more experienced experts may differ, but this has been my experience with these issues. Rusty

Is there a way to know whether a particular transmission already has offset cotters without splitting the case?

Having never taken apart any motorcycle engine including a 305 I ask, is it possible to split the cases with the engine upside down and remove only the bottom half, leaving the top intact as you work on the trans?

[48lesco]

That's quite a bit of slop. I would try and figure out where it's coming from. Is it from wear on the shift forks / gear / rollers / drum? Did you have the shift drum retainer installed when you were pushing and pulling? I would replace what's worn while your in there.

Yes, you can split the cases with the top end intact just be careful not to drop anything "down" into the head or cylinders.

No, don't know of a way to tell if your cotters are offset except that if you have 20k miles on your bike and you're staying in second gear you probably do.

[flyin_]

Yes my shift drum retainer was installed. the majority of the play appears to be in the shift drum, movement of the whole fork, and not play between the gear and fork. how much side play on the shift drum is acceptable? Is play of .5mm to 1mm acceptable?

thanks

[48lesco]

I would say 1mm would be OK but you appear to have more than that. Find the source of the slop. Does the whole shift drum move axially and if so why? Is the drum or retainer worn? Do the forks wiggle or move axially on the drum? I'd at least check/replace the pins and rollers in the forks while your in there. There's a lot of parts in play here, and a little wear in each one all contributes.