Hey Mezo, that is a early model gearbox and the output shaft is the top one The lower one goes to the clutch.
Regards Eric

Eric66 wrote:Hey Mezo, that is a early model gearbox and the output shaft is the top one The lower one goes to the clutch.
Regards Eric

Didn't i say that Eric? its from an 84 model.

So whats with the thread then? there was me thinking the sprocket goes on that? can you post some pictures of a 3AJ output shaft please then for Dunc to study.

Mezo.

I've got the service manual and parts fiche thanks to the folks here and they give me some idea what to expect. Also, I'd like to point out that although I'm doing the work myself, I do have adult supervision. I'd attempt taking the flywheel or the clutch off myself but wouldn't attempt to remove or split the engine unless there was someone around that I was confident could put it back together and back in.
Right. Off to work. I'll post some pics when I get back.

Dunc.

Keep up the good work dunc! Your spirit definitely deserve some

Ay up folks,
Successfully split the engine today. Only asking for help with particularly stubborn fastners and advice on what to take off next.

Apart from the drive shaft, things look pretty good:





The only obvious wear is on the 5th gear on the main axle:





In fact, the only problems either I or Diego the mechanic could find were a lot of carbon in the combustion chamber:







Which I put down to running rich due to being at altitude. There's a machine shop down the road that specialises in this sort of thing, they'll polish my cylinder head (fnar fnar) and regrind the valves for US$20 so I'm going to take it round tomorrow, and also some wear on the oil pump rotors:




What do you all think?

Thanks,
Dunc.

Doesn't look to bad really, bore looks fine but yeah the fifth gear wants changing while its apart.

Mezo.

BTW, the "Gear 3" part of the starter clutch that I had machined back in Peru is holding up nicely. Had a straight edge all around the bearing face and there's no sign of any wear.
What the guy did is turn down the bearing face on a lathe, fit a stainless steel sleeve over the top, weld it in and machine it to fit.



My dad has a lathe. When I get back, I'm going to see if I can get him to teach me how to do this.

Quick question; both the crankshaft and the balance shaft both have dirty great big oblong shaped woodruff keys in the gear assemblies in the clutch side of the engine. Is the correct term "Woodruff key"? The only woodruff keys I've seen in the past have been half moon shaped.

Woodruff key is the correct term for the half moon type.

In English we call the Yamaha type a plain key or a square key. Replace yours if there is any sign of wear. You can buy key steel from engineering shops and places where they repair electric motors. The Yam uses 7mm square.

ActionManMelb wrote: In English we call the Yamaha type a plain key or a square key. Replace yours if there is any sign of wear.

No sign of wear, I just wasn't sure what the things were called but then, I've never before split an engine. Last time I needed a woodruff key, it came from a V8 Chevy crankshaft and had to be filed down to fit
Let's just say that I'm now a big fan of windy spanners.