Transmission question and intro

[adam14]

Hello all,
I bought a 1977 F2 with a frozen motor. Its had two previous owners before me and the guy I bought it off of had a lot of history for it and said it was running well when he parked it 15 years ago. It has been thrashed over the years as Oklahoma weather can be a little rough on these machines. But I took his word for it and pulled the top end to find that one of the pistons was frozen pretty good.( I tried soaking it for a week or so with a concoction but it wouldnt budge so i had to open it up.) After that was free'd up, with motor on bench, I decided to run it through the gears by turning the crank and shifting with my hand and noticed that when shifting from 3 to 4 sometimes it doesnt completely engage and free spins like its in neutral. Then I have to shift down to N or 1 and try again. Unless I really push up hard on the shifter and feel a thud and a second thud, it wont go into gear.
My Question is, due to my lack of transmission knowledge on these bikes, is that normal for the 750's??
Ive tested going through the gears this way on a honda cx once before and they all went smooth, they felt like they were jumping into the next gear with ease. This bike seems to want to be forced in those gears so to speak with some extra muscle.
Thanks for reading this long winded description, all and any advice is much appreciated.

 

[amc49]

Not guaranteed of course but it could be fine. Turning crank by hand turns the trans too slow to line up the synchro lugs easiest. If you break the clutch down to be no connection to the crank then spinning the shaft by hand spins trans faster and then may shift more completely. DON'T force things, if you are trying to get it in gear with both lug rings impacting the outside of lugs themselves you only damage things more. The spinning (and faster is better) is what allows the change to be made. It allows the gears to line up where the lugs can fall into each other as proper.

Then again, there could be synchro damage on one gear set, it happens. Maybe not though, often your trick there works on most gears in bikes but typically one or two will not go in as easy.

 

[adam14]

Thanks amc. Plus one on the spinning speed I definitely overlooked that. Im most likely just not generating enough speed at that gear. It does get "stuck" so to speak inbetween those gears and acts like it's in neutral when the shift isn't fully compete. I found this out when I was trying to put it in 5 and spin the rear wheel to free the motor when I first brought it home. I thought it was in neutral when it was really stuck between 3 and 4.
i think you're right and it'll be fine. Just wasn't sure if anyone has had this before.

 

[amc49]

You have figured it out...........................