I've bought something sh*t

[Rollin]

Whilst my Monster is awaiting repair I decided to buy a crap 37 year old scooter to 'have fun' on in the meantime.

Now I seem to remember that riding around Ibiza on a 50cc scooter in shorts and flipflops was a laugh, but 30 years later and in sunny Manchester..perhaps not so much.

Anyway..I also wanted something basic to try and fix up over winter.

This thing has numerous minor cosmetic problems (apart from generally looking crap) and probably some major problems too in the mechanical department. Some of these are becoming apparent pretty quickly.

First off, the vacuum fuel tap has been replaced by a regular fuel tap. This means I have to remember to turn it off or fuel pisses over the floor. If I want to fix this, do I need to find a vacuum fuel tap specific to this scooter, or will any generic 50cc scooter vacuum tap work?

I decided to change the gearbox oil as it was an easy job. There was only about 100cc of oil in it instead of 600cc.

I decided to have a bit of a test ride after doing this and everything was going fine. I even started to smile a bit. Obviously it's slow, but it reached an indicated 35mph and changed gear automatically OK.

After riding for about 15mins, something bad happened. The scooter bogged down when trying to rev it and an increasing amount of white smoke started issuing from the exhaust. It then stalled and more white smoke came from the exhaust/engine area as if about to catch fire. I looked down and saw the paint on the exhaust cover bubbling so something was obviously getting quite hot!

I decided to let things cool down whilst pushing the fking thing 2 miles back home, looking like I'd nicked it.
I checked things over in an amateur fashion when I got home, and everything seemed OK. I took out the spark plug and that looked OK too.

I started it up again and it ran OK but after a few minutes, more white smoke. Not as much as when it stalled but more than I would think is normal.

So, any pointers to where I should start looking to fix this....or should I just bin it

Oh, here's a picture....

[Rollin]

Moulder said:

Looks too nice to bin and easy enough to push. On that two miles out I bet women were wanting you and men were wanting to be you...

Is it two stroke? If so is it running on pre-mix or does it have an oil pump and tank?

I did get quite a few looks. The basket came in handy for helmet storage whilst pushing it home. I'd pushed it a few hundred yards juggling the helmet before it dawned on me though.

It's 2 stroke and has an oil pump and tank.

One more symptom is that when I rev it on the stand, the revs don't drop very quick. I'm lead to believe that this might be significant.

[Rollin]

anonymous said:

[redacted]

It is aircooled and the smell was an oily petrol type smell. Definitely not steam.

I've resigned myself to the fact that I'll probably suffer serious injury if I come off it, as there's no way I'll be wearing any protective clothing whilst there's the risk I may be pushing it around Salford again.

[Rollin]

Thanks for the help so far. I'll check the carb mounting tomorrow. I seem to remember being able to move it around as if it's attached to something else rubber as well as the hose from the airbox.
Crank seals are £1.88 each so I may as well get them ordered and attempt fitting.
The model is a Passola.
The fuel tap has to be turned on for about a minute before it will kickstart, but it starts easily.

[Rollin]

graham22 said:

Yamaha Pissola - remember having to work on the feckin things 33 years ago.

Exhaust nuts seizing, having to explain to a customer that it will cost mega bucks to fit a £6 rear tyre as the exhaust has to come off and exhaust studs drilling & replacing - I think we did do one tyre change with the wheel still on the bike.

Gynecologist skills needed to change any control cables as these have to be done through the headlight aperture.

35mph - wow, usually the exhaust gunks up with years of cheap 2 stroke oil giving 20mph max.

Once had one in pissing out oil from everywhere, the owner had put 3 bottles of Tesco's finest 2 stroke oil into the transmission filler & 'it still isn't full'.

Horrible little things - nothing like hiring a modern fat wheel moped in the sun.

Bookmarked your pain.

eta - crank seals, probably engine strip required as they will be lipped.

Edited by graham22 on Thursday 31st August 09:58

So you're not keen then?

I'm going to try and remove the engine this weekend and see if I can fix it.
Bearing in mind that I'm a complete amateur (but keen and with nothing to lose), what work would you suggest I do whilst its out?

Looks like exhaust removal might be critical so I'll have a go at that this afternoon.

[Rollin]

Graham22 was correct. There's been a lot of progress this afternoon..


[url]



Single sided swingarm...just like the Monster

Everything came off easily thankfully. The bike's only had one other owner and I think it might have been quite well looked after.

I need to remove that plastic fan thing but the screws are not turning at present. I've doused them with WD40 and will try again tomorrow.

Whats the best thing to clean all the engine bits with, petrol?

Edited by Rollin on Thursday 31st August 19:51

[Rollin]

Oil seals, gasket set and front pads turned up today. The last ride revealed that the front brake was pretty useless. The rear one worked really well.

I also thought the rear was really bouncy on the current spring/shock absorber. I assume that things have moved on in this regard since the 80's so might look at swapping it. Don't want to....ahem....ruin the handling though. Advice gratefully received. Will obviously keep the original so it can be swapped back when prices for these start rising

The top of the piston is rough and black, so I believe I need to clean that up. There seems to be very little gap between the piston and cylinder, a minute amount of side to side movement.

Still can't release these 3 screws holding the plastic fan on. Off to get some better penetrating/releasing oil.

[Rollin]

WinstonWolf said:

An old skool impact driver will normally shift those.

Doh...Thought that may cause a bit of damage, but it didn't and now the dismantling can continue.

[Rollin]

Apparently this thing has 2 clutches. The rear one look worn out to me and I can't find a replacement anywhere.



I also need to remove this bolt which manual says need a special tool.

[Rollin]

Found magneto removal tool! Cant2 find clutch stuff

[Rollin]

Bike and engine is now in bits.

I have split the crankcase to have a look and clean.

Crankshaft came away from big end bearing OK on transmission side, but the other side won't budge from crankcase.

Any ideas how this can be removed? I only want to remove the crankshaft, not the bearings as they seem good.

The transmission side crank oil seal was knackered so thanks to everyone who gave the diagnosis!

[Rollin]

Bike is now at the point of being put back together again!
Engine has been taken to pieces, cleaned, seals replaced, piston/rings/gaskets ready to replace.

I've hit a problem that I hope someone can help with. There is an oil pump gear which fits over the crank shaft, which then engages with a cog on the oil pump itself. The thing is, there appears to be no way for the gear to lock onto the crankshaft. I can spin the crankshaft whilst holding the oil pump gear still. The clutch assembly fits onto the crankshaft next and then a bolt clamps everything together.
Is friction enough for the crankshaft to turn the oil pump gear?

There is nothing on the crankshaft to engage that slot on the oil pump gear.

[Rollin]

I have something that fits into the slot that you can see on the end of the crankshaft but that doesn't interact with the oil pump gear.

The oil pump gear slides much further up the crankshaft and there isn't anywhere on the crankshaft to fit a woodruff key.

[Rollin]

The nylon thing is the oil pump gear. I've not fixed the clutch basket on yet, but if the oil pump gear turns at that point, then it's only because everything would be clamped together. I would have thought that there would be a way for the oil pump gear to positively engage with the crankshaft. Especially as there is a slot in oil pump gear.

[Rollin]

cmaguire said:

When I said oil pump gear I meant the pump gear itself. If that still turns when you try to hold it then the weirdo thing they call the oil pump gear can't be loose.

At the point of assembly shown in the photos, when I turn the crankshaft, neither the nylon gear or oil pump gear turn.
I don't know if this will be different when the clutch basket and nut is all tightened up.

cmaguire said:

I presume that weirdo thing has a spiral rib on it to turn the oil pump gear itself

Yep.

[Rollin]

WinstonWolf said:

Does the bush go on first?

No

[Rollin]

WinstonWolf said:

That's definitely a Woodruf slot, I fitted hundreds of the darn things as an apprentice

I understand what you are saying, but there is nowhere on the crankshaft for a woodruff key to fit

[Rollin]

cmaguire said:

That slot may be to allow oil to move or irrelevant. The oil pump usually requires little force to turn, if the weirdo gear is clamped when you tighten the clutch then that should be more than enough.

I'll just have to assemble everything and see what happens.

[Rollin]

cmaguire said:

Rollin said:

cmaguire said:

That slot may be to allow oil to move or irrelevant. The oil pump usually requires little force to turn, if the weirdo gear is clamped when you tighten the clutch then that should be more than enough.

I'll just have to assemble everything and see what happens.

I can't see all the diagrams or parts, but the slot in the weirdo gear might be because that is an interference fit bushing in the weirdo gear and the gap is unimportant.

I think the special sealed spacer may be involved in this mystery somewhere, perhaps with a dose of centrifugal force and oil action when the engine is running (if the weirdo gear doesn't go tight when the clutch nut is fixed)

Thanks