Thanks for the info schu. I will give it a go. Parts ordered, again, so hopefully able to reassemble end of the week. There is a nice used one on eBay for £40 but it is in the states so another £80 for postage. So it can stay there annoyingly.

I wonder why the nuts were only hand tight in the first place? I am sure it wasn’t to change the clutch!! So possibly to change the crank seal. I will try to see if there are any markings on it that may indicate it’s been replaced.

Thank you for the help and advice once again.

Look out for a resolution to this issue at the end of next week and I look forward to my next issue from this bike to share with you. Cheers.

I see the supporting roller spacer thingy missing from the change arm as it sits against the claw arms. Look closely in the pic. Also a driving ear missing from a fiber plate in one pic. Probably all unimportant compared to the original issue. Keep the timing well back. Think MarkT says 2.5mm not 2.9. If yours has the built in advance it must be held open on advance. Big thing to on that side us to be sure to tighten the flywheel nut very tight!!.

Thanks RT.  

this bike is a right pig in a poke.   The timing I hope I have right and noted the 2.5 but will check once more when I put this back together.  I also find I am missing the tachometer drive gear and shaft. 

seriously would have been easier to put a different motor in this. Everything I do leads to more hassle later.  It’s a test alright!

by “roller spacer thingy” do you mean there should be something that sits in the slot on the change lever bracket?  Sorry I don’t know the correct term?  I have tried to look at exploded diagrams but I can’t work it out…. Any more help would be gratefully received…

all clutch plates being changed. 

thanks for taking the time to reply.  

it’s not a project rewarding me with joy at the minute. I will carry on however!

thanks as ever, ian

Be #30 if i'm viewing your pic correctly. Cheers.
www.cmsnl.com/yamaha-rt1-1970-usa_model8...e-lever1_2141817800/

images.cmsnl.com/img/partslists/yamaha-r...gyau0779b-2_5c3e.gif
Be careful assembling the clutch with that flat bearing & fit it the right way around. That flat bearing likes to drop down & get trapped over the end of the spacer. It's a bit of a fiddle of an operation fitting it all without loosing it.

That’s brilliant RT. Thanks for taking so much time to reply in such detail. It makes sense now. I will try to source one and the circlip (no 25) in the diagram you attached.

I have read somewhere (service manual I think) that it’s best to use a blob of grease to hold those bearing parts in place on assembly. May give me a fighting chance..

Identified the tacho drive parts and in negotiation with USA seller to supply. Fingers crossed they will be ok. Need to remove the parts in my case next. The driven gear is very worn. Hopefully will just pull out when the stopper is removed.

I hope the engine wasn’t stripped down to get to the gearbox and someone went “uh oh “ when they saw inside and quickly bolted it all back together.

I will find out I am sure.

Good job it’s a hobby and not a business venture. Otherwise it would have been stripped and sold for parts by now.

All other parts now ultrasonically cleaned and clutch basket fingers filed and looking better.

Waiting for the postman now.

Once again this site come up trumps. Thanks.

Dont worry & it's all good but 25 circlip is related to the arm not the roller. Roller sits on a peg on the arm & can't escape when the change arm sits on it. Parts views can be a bit deceiving. You'll workout out but hope there's not too many more nasty surprises.

Gotcha.  

you wouldn’t know I did general engineering drawing at school would you.  It was 50 years ago though to be fair. 

thanks once again. 

I hope so too, but it is what it is I suppose. 

ian.