Topic: Gearbox issue - can't get into 2nd

[Gavin]

Hi All

Sad to say that after a very successful first few runs, I've now run into an issue with my bobber - 1975 550 (F1 I think).

Fired her up the other morning and whilst idling the bike stalled - Not certain but I think she might have slipped into gear. Didn't think anything of it as it does that sometimes when starting from cold.

Now 1st gear and Neutral both select and operate just fine, however, I cannot select upward of Neutral. The transmission/gears are not selecting into 2nd or anything above - feels like it's locked part way and cannot engage. The bike does drive fine in 1st though and there's no odd noises (grinding or otherwise).

So, tried adjusting the clutch to give more tension/free play- no change. This morning I drained the oil out and pulled the right side cover to start nosing around. The clutch basket's fine but I can see that when I click the gear selector up with my foot to head for 2nd, the selector just won't quite engage into 2nd gear - Used to do that just fine (hitting Neutral used to be the challenge!).

So, before I start pulling the whole engine out to get at the gearbox and start looking for faults, can anyone offer any advice, experience or pearls of wisdom?

My guess is that a 'selecting fork thingie' (technical term) may be bent or something. I should state here that I'm an enthusiast, not a trained mechanic! 

Looking at the base of the engine, is it possible to drop the sump out the bottom of the frame and access the gears without needing to remove the entire engine from the frame?

Just so you know the history, the bike's recently been chopped around and rebuilt. I didn't do the engine rebuild myself so I can't vouch for the experience of the guy that did it. It was however operating pretty well last week on her maiden voyage.

Cheers all

Gav

[bryanj]

You cant do anything to the trans without removing the engine and splitting the cases BUT before that remove the clutch cover and check out that the operating mechanism hiding behind the cluch is working OK, if you do have to pull the motor the work is not a waste as it all has to come off to separate the cases

[Gavin]

Solved!

Quite proud of myself actually as I've not worked on an engine at this level before. Got the whole engine out, stripped it down and found the issue. One of the dogs sheared off a gear and got wedged inbetween 2 other gears, effectively preventing them engaging and stoping me shifting up.

Just need to replace the gear now & then we should be up & running again!

[bryanj]

Well done, most gears are still available from Honda or WWW.davidsilverspares.co.uk Change the mating gear as it will have damage and look carefully at the selactor fork