Scooter died on me!!!

[Acen]

Riding home yesterday and my scooter died a death. i cant use the kick start as its rock solid, ive got a bad feeling that engine burned all the old and the piston is seized (this is what a stranger told me who stopped in the street)

Ive left the bike in the street. its about 2 km to my house so i have a long push!!

The problem is what do i do now?? Its not worth repairing as Im sure a new engine ect will cost more than the value of the bike.

Does anyone know how to scrap a scooter?? Are there companies that will pick it up from your house and scrap it (albeitin take off all the valuable spares).

I need all the paperwork to be done properly!! Any suggestions anyone???

cheers in advance for your help!!!

Acen

[swerve]

When was the last time you checked the oil. That's the 1st thing I would do. If no oil then no engine.

[Colinm]

Is it a two stroke or four stroke scooter? what engine size, make and model?
It sounds like its seized ok, but if its a two stroke it can be cheap enough to get it going again.

[Acen]

its a four stroke 125cc will check the oil tonight but i think its finished.

now have to work out what to do with it.

if it has sieized im assuming an expensive repair so it seem the death of the bike

[Acen]

When was the last time you checked the oil. That's the 1st thing I would do. If no oil then no engine.

i honestly cant remember the last time i checked the oil, more that 12 months i think. It had been in the garage for months and I have only just started using it again.

it was running perfectly so i did not think about the oil!!!

[olive]

I would repair it.

First thing is get it home before parts disappear off it. Your profile doesn't say where you are but if you were near me I would put it in my trailer and take it home for you.

Have a look on Mil annuncios for a replacement engine - if yours is tatered. There will be some around that have been accident written off. Or buy one off Ebay and have it shipped out.

It would be a nice little project .

[Colinm]

Get it back home and have a look at it. You may find a similar one with crash/front end damage and be able to salvage an engine from it. There are some generic engines fitted across a range of scooters so don't fixate on getting exactly the same model.

Piston and rings are cheap enough

[Acen]

will get it home and have a think about it.

I work full time and have a young family so dont have the time for it nor the technical expertise.

thanks for the advice will keep you updated.

[ajtg1952]

When an engine runs out of oil it generally seizes, as in this case. The oil cools the engine and the air or water cools the oil. However, unless it stopped with a large clunk or bang it may not be fatal. As the oil disappears, the piston heats up and expands as does the oil control rings and the friction increases till the piston can no longer function. Once it has cooled the damage may not be too great. In fact I have been able to re-start an engine that had seized by turning the crankshaft and freeing the piston. The rings needed to be replaced and it was as good as new.

So don't write it off till you have had it checked. Scooter engines are robust wee things!

[Acen]

what are the rings????

if you dont mind me asking!!!

I take it that I should not persit in trying to start it!!!

is it simply too late to add oil now???

the kick start is solid and wont move.

[ajtg1952]

The rings control the oil in the piston and stop it getting into the burning chamber. They can physically weld themselves to the side of the cylinder.

The kick start will not free a seized engine; it would probably break.

There will be a cover plate on the bottom of the engine in line with the crankshaft. The crankshft is the bit that is turned by the big end of the piston and in turn the crankshaft turns the driveshaft which goes into the gearbox and drives the bike. The cover plate is usually held by three bolts. Take this off and you have access to a very large nut, usually 22mm. This is the physical end of the crankshaft. Take the spark plug out, squirt some WD40 into the hole, leave it a while and then try to turn the big nut clockwise. It takes a lot of grunt, but if it is going to free this is the only way you will do it.

[swerve]

Found this for you. Worth a read. Hope you find it helpfull.

Here is a brief description of " How does a piston ring seals the combustion chamber from crankcase? "

The piston rings have two type of clearances in their grooves. One is radial and other axial. Due to this clearances, the piston ring is free to move in the groove. Also the piston rings have some springness and they will always be pressing against the liner wall. But this springness is not enough to seal the combustion chamber against the gas forces.

When working, the piston is sitting on the bottom of the piston ring groove and they are pressing against the cylinder liner wall. Due to this there is a small clearance at the top and at the back (towards centre) of the piston ring. Due to this clearance, the gases can go to the back of the piston ring from the top clearance and press the ring hard against the liner. This causes it to become almost gas tight.

There is another clearance provided at the ends of the rings. This is to compensate for the change of length of the piston ring due to temperature changes. Due to this, the small amount of gases leak past the rings. Just like a air leaking through small hole. So to redue the pressure to a small level, number of rings are provided. Each one reduces the pressure a fair amount and the last one reduces it to crankcase pressure.

If these gaps get blocked due to carbon deposits and piston rings are not free to move in there grooves, the gas pressure do not act from inward side, but due to taper on the rings will act from outward side towards inwards. This will lead to sudden collapse of the ring and breakage.

Lubrication system
The engine lubrication system is designed to deliver clean oil at the correct temperature and pressure to every part of the engine. The oil is sucked out the sump into the pump, being the heart of the system, than forced through an oil filter and pressure feeded to the main bearings and to the oil pressure gauge. From the main bearings, the oil passes through feed-holes into drilled passages in the crankshaft and on to the big-end bearings of the connecting rod. The cylinder walls and piston-pin bearings are lubricated by oil fling dispersed by the rotating crankshaft. The excess being scraped off by the lower ring in the piston. A bleed or tributary from the main supply passage feeds each camshaft bearing. Another bleed supplies the timing chain or gears on the camshaft drive. The excess oil then drains back to the sump, where the heat is dispersed to the surrounding air.

[Acen]

many thanks for that