New Member Hello from England and help with my YDS3, please...

Hi Guys,

New fella here, from the UK.

I bought a Yamaha YDS3 back in March 1965, my first new 'bike and I've had a hankering to get another for many years. Then late last year I spotted a totally original one, with just 1,900 genuine miles on! Trouble was, it was in Colorado, US. I saw it running – it started and ticked over nicely, with just little faint puffs of bluey smoke, as per normal. I shipped it here to the UK and hoped to get it running almost straight away after a quick service.

But... I just cannot get it to run properly, and finding out what is wrong is driving me nuts. I suspect “carburettors” but I'm unsure if it could be crank seals. Here's what's happened; please let me know what you think...

As I say it started and ran perfectly OK in Colorado (at altitude?) - it started and ticked over fine, slight puffs of smoke (cold engine probably, with choke on). Then I shipped it to me here in the UK. Now, I'm at sea level (in glorious Torbay!) so could this maybe lead to the following problems?

It would NOT start, not a cough, hiccup, nothing. So I heated up the plugs, then bumped it down the hill and it reluctantly coughed and spluttered into life. It didn't run well, and my God, the SMOKE!! Massive amounts of bluey smoke billowing from both silencers, one slightly more than the other possibly. I got it ticking over, sort of, but then the tickover suddenly ran away and the revs climbed (as it warmed up??). I got the revs back down by carefully shutting the choke but it just wouldn't run properly, stuttering and almost dying, and the huge amount of smoke was becoming an embarrassment...!

I'm unsure whether this smoke is carburation, or is it the oil from leaking crankshaft oil seals that's burning?

I'm no mechanic (sadly) and my tinkering has often got me more problems than has cured anything, so I'm reluctant to just 'dive in' without a proper diagnosis. Servicing a carb is something I've never done, so altering jets, etc., is NOT something I really want to do. I can get "carb service kits" here, but I'm chary about doing this myself - starting something that I cannot then sort out.

OR... should I just get a local garage to have a look?

And what happened to the 'bike between Colorado and the UK??

I'd really appreciate any words of wisdom. Thanks.

Anyway, glad to join you all, and I've already learnt a lot of stuff, just by reading through the Forums.

Here's me, back in 1965, on my red YDS3...



And here's my Colorado YDS3 - a shame it's not red, which I prefer...



Even the toolkit is original and immaculate!

 

Very many thanks, guys for such prompt and helpful responses.
That's a great write-up, Murdo.
So a lot more work to get to the bottom of this problem, then.
It was the contrast between how it ran in the pre-purchase video and how it's running now that puzzled me.
I'll let you know how I get on.
Many thanks again.

 

Right... I've been mulling over all you've said, guys. I think I need to firstly rebuild/clean the fuel system properly, starting with the carbs, refurb the petrol tap, fit new fuel lines, replace the fuel with fresh, and THEN see how it runs.

The gearbox oil level appears OK, but it doesn't need a lot of oil leaking into the crankcase to be smoking like that.

Something I need to know... can the crankshaft oil seals (not the labyrinth seal in the middle) be replaced without splitting the engine, just by removing clutch and generator?
How are the old ones pulled out?
And how are the seals actually replaced... just pushed in? Tapped in? Drifted in?

If I figure this is too big a job for me to do on my own (I have no-one to help me out), as I need the crankcase covers respraying anyway, I think putting the 'bike into a workshop to change the crankcase seals for me is probably the right way to go. I'm pretty sure this is too big/difficult a job for me to undertake (I know my limitations as a 'mechanic' fortunately!!) so I'll then see how I go from there. I've located an "old 'bike" garage not too far away, so I'll go and suss him out, as soon as I can get over there.

I'm in awe of you guys who have full workshops, with lathes an' stuff, but more importantly, the knowledge and skill to repair these old 'bikes - I'm thinking of Murdo, for example,repairing his YDS5 kickstart splines...!!! Ye Gods! What I wouldn't give for those skills, and hats off to you, mate.

I'll keep you posted...

 

Many thanks, Murdo. Good info, helping me to make decisions.
This is really NOT the job for me to attempt. I'd do this with an old scrap moped or something, to practice on - but not my beautiful YDS3!!
Thanks again.

 

Oh, one other thing I don't know how to do... How do the rear suspension units come apart, please? The chrome is poor on one and I might be repainting the 'bike (in that gorgeous candy apple red!) so I will need to get them apart at some stage.
Is putting them back together straightforward?
Thanks.

 

Thanks, Grey.
I'm up to my ears in hard copy YDS3 manuals that I've sourced, but NOWHERE does it show stripping these rear units down?? I was beginning to think it was a secret!!
Cheers.

 

Thanks yet again, Murdo. I'm guessing I'll need some sort of clamp device - I know that "springs unleashed" can be pretty lethal!

 

Time for an update...

I decided there was too much 'unknown' for me to start tinkering and 'see what happens'. So, I've been lucky to find a great 'old school' mechanic and I entrusted the YDS3 to him. He's been brilliant.

A carb and petrol tap strip down revealed a ton of sludge and crap, now all cleaned out. An ultrasonic clean for the carbs, plus rebuild kits for carbs and tap, and the Yam is running sweet as a nut! I'm certain the seals are OK. So... Panic over. New oil in the two stroke tank, 97 octane fuel, new tubes in the tyres, a bit of fettling (clean the wasp's nest from the air filter and fit a new battery!) and it's now running around like the almost brand new 'bike it is -just 2,000 miles from new!

Thanks again for the help and suggestions, guys.