Conference terri::cars_uk

    
    Re .1
    
    Ah, but you don't get the neato stripes do you ? :^)
    
    Mark

For the moment, the stripes can wait !!!

How about some constructive comments please :-)

> How about some constructive comments please :-)

Have you considered buying the necessary parts, a manual, and doing the repair 
yourself ?

Lawnmower engines are pretty basic things, and don't take too much effort to 
strip down, fix and re-build. It shouldn't take you more than some of a
weekend.

If it's a 2 stroke, even easier !

>How about some constructive comments please :-)

Bit difficult if we don't get more details.
Is it four-stroke, two-stroke. Hover, cylinder, tractor ?
Has it been 'chipped', bored-out, injection, turbo ?
Centrifugal clutch ?
12",14",16" cut ?

	Alex

    The motor probably stopped because the blade got bent against the
    chassis of the lawnmower. If you could unbolt the blade and examine the
    damage to the drive more closely you may be able to straighten it out
    fairly easily.
    
    Regards,
    
    Brendan
    

Handy Hints #734:

If you can arrange to jam a stone in the blade with the crankshaft 180� round
from the original "accident", then this should bend the shaft back straight...

But seriously, buy a manual, strip it down, then go and buy the new bits (once
you can see what needs replacing) and put it back together.  Just make sure that
you don't get one of the "extra" bits that are inevitably left over after
engine rebuilds, caught in the blade when you first fire it up, or you'll be
back where you started!

Scott

OK ... now for some more details.

It's a four-stroke, although I don't see that it makes any difference.

It's a rotary blade type ... like a hover mower, but with a petrol engine
and wheels to keep it up off the ground.

From the position of the piston with respect to the blade, I assume that
the blade bolts on to the end of the crank-shaft. This is the bit that
is bent. Infact, it is bent to such an extent that the engine no longer
turns.

Buying a manual is not easy. The make is Italian, and I'm living in France.
Getting parts could also be a problem.

I have already stripped the thing down in the past ... the previous owner
was running it as a two-stroke, and the engine gummed up, so I took it
apart, found out that it was a four-stroke, cleaned it up, and it ran.
I haven't as yet stripped down the bottom end.

If the shaft that is bent is bolted to the crank, then replacing it or
getting it straightened should be possible, assuming I can find the parts
or someone who can do it for me. My only worry with straightening it is that
if it breaks off with the thing going, I'm likely to loose my feet !!!

Has anyone already had a similar problem, and if so how was it resolved ???

>> the previous owner was running it as a two-stroke

How can you run a four-stroke as though it's a two-stroke?  The mind boggles!

Or do you just mean he was putting two-stroke oil in the fuel, assuming it was
a two-stroke engine...?

I doubt if it's a separate shaft bolted to the crank.

Best solution would be to get a new shaft... if you can find the manufacturer's
address, write to them and see if they can help.

Failing that, get a black-smith type person to heat the shaft and straighten it,
although this isn't gong to be very satisfactory.

Scott

    
    Mark --
    
    
    The key question is whether the component is merely bent, or broken. If
    bent, & you can dismantle it sufficiently, the man with a very hot
    forge & a big hammer can probably get it straight again. May need a
    (final) small hammer to get it truly square to the crankshaft .......
    
    You may need to re-harden the shaft afterwards -- depends what load it
    takes. Shouldn't break if done properly.
    
    Don't be tempted to belt it straight while cold. Stress factures etc
    will be highly likely. Re-engineering a crank from scratch is always a
    possibility, providing you have the skill, the machinery, the time -- &
    the right temperament.
    
    Alternatively, many lawnmowers can take a variety of replacement
    engines -- much cheaper than a brand new mower.		
    
	Colin

    Forget trying to straighten the shaft...... it'll be out of balance and
    you'll have one he** of a job to get the blade to run true and not
    scalp the grass at some point of its rotation. 
    
    If it's one of the common makes of engine (Honda, Yamaha, Lombardi,
    Briggs and Stratton) you won't have any problems getting spares. The
    rebuild is straightforward but you'll need a couple of special tools to
    do the work. The workshop manual will help.......
    
    If you are going to pay someone to do the work it might be cheaper to
    swap the engine. 
    
    Watch out for damaged bearings on the crankshaft and also damaged seats
    for the bearings in the crankcase castings.

re: the last three or so ...

Thanks. Exactly the type of info I was looking for.

Colin,

 If the shaft is hardened (excuse the obvious ...), wouldn't it have
 broken rather than bend ??? I've never known a hardened crank to bend,
 snap yes, but bend ???

Anyway, I'll strip it down a take a closer look at the weekend when
I have a bit of time. As soon as I have the answer, I'll post it.

I'm sure you're all dying to know :-)

    
    Is it the blade attached to the crank thats bent or the crank itself?
    
    If its the crank itself, it will need to be balanced as well as
    straightened otherwise the thing will vibrate out of your hands
    ;-) 
    
    Why not just buy a second hand mower?
    
    R.
    

Took the motor apart ... the crank-shaft is bent, and the engine case
is a bit cracked where the crank-shaft passes through it.

Replacement price for the crank-shaft is �60. A new motor is only �100,
so this looks like the best alternative.

Finding someone willing and able to take the bend out of the crank-shaft
has drawn a blank.