Atco Commodor B17 Stalling
 

Hi....I inherited an Atco Commodor B17 Mower with the house we bought.
It has run fine since last August.
This year, I have noticed it seems slightly noiser(and I mean slightly) than last year and seems to struggle through grass when it gets something like "long".
Yesterday, After up and down the lawn twice, it slowly got slower and slower till it stalled.
I tried to restart it with the pull cord and it nearly broke my wrist.
The engine seemed to have seized.
After about 15 mins, it "unseized" itself and I was able to start it.
Again, after 3 or 4 times up and down the lawn, it ground to a halt. Seized again.
This now is the norm.
From "cold", it will cut for maybe four or five minutes and then seize.
Someone told me to put 2 stroke oil in the petrol which I have but it doesn't seem to have done much to help.
Whats wrong here???????
Why does it seize after a few minutes running and why does it unseize itself.
Why hasnt it done it for the last 10 months?
Is it the engine itself at fault or perhaps a bearing seizing when it gets hot?
How can I fix this problem please?
Many thanks in advance.

Atco Commodor B17 Stalling
 

"kanewesley" wrote in message
...

Hi....I inherited an Atco Commodor B17 Mower with the house we bought.
It has run fine since last August.
This year, I have noticed it seems slightly noiser(and I mean slightly)
than last year and seems to struggle through grass when it gets
something like "long".
Yesterday, After up and down the lawn twice, it slowly got slower and
slower till it stalled.
I tried to restart it with the pull cord and it nearly broke my
wrist.
The engine seemed to have seized.
After about 15 mins, it "unseized" itself and I was able to start it.
Again, after 3 or 4 times up and down the lawn, it ground to a halt.
Seized again.
This now is the norm.
From "cold", it will cut for maybe four or five minutes and then
seize.
Someone told me to put 2 stroke oil in the petrol which I have but it
doesn't seem to have done much to help.
Whats wrong here???????
Why does it seize after a few minutes running and why does it unseize
itself.
Why hasnt it done it for the last 10 months?
Is it the engine itself at fault or perhaps a bearing seizing when it
gets hot?
How can I fix this problem please?
Many thanks in advance.


OK, the obvious question is...is it out of oil? It's acting like it's out
of oil. If the oil level isn't low, maybe it isn't getting circulated
somehow. I would think a mower would be splash type lube, but maybe it has
an oil pump bad? Oil line clogged? -Dave

As Dave said check the oil and/or top it up or replace it with the correct grade.
And also check it is getting enough cooling air. "Heat seizure" is pretty common due to lack of cooling. May also pay to check the spark plug for the colour at the tip, as a too lean a fuel mixture can cause overheating in extreme cases.
Good luck

Atco Commodor B17 Stalling
 

I would like to assume that you changed the oil when you received the mower
and again at the start of the season. Check the oil level, the manual will
explain how and what to look for, of course if needed fill with oil. if you
are low on oil then what may be happening is that as the engine warms steel
parts expand at about 7 parts per million per deg F. while aluminum expand
by 13 parts, if as I would expect there has been a lack of oil to lubricate
the engine then scoring has occurred and the rise in temperature causes the
scored parts to bind until they cool again. Please note if the engine lacks
oil then continued operation will eventually destroy the engine.

If the engine has been maintained with the proper oil level, other parts in
the gearing may be binding causing the problems described. At this point you
might choose to consider professional help.

"kanewesley" wrote in message
...

Hi....I inherited an Atco Commodor B17 Mower with the house we bought.
It has run fine since last August.
This year, I have noticed it seems slightly noiser(and I mean slightly)
than last year and seems to struggle through grass when it gets
something like "long".
Yesterday, After up and down the lawn twice, it slowly got slower and
slower till it stalled.
I tried to restart it with the pull cord and it nearly broke my
wrist.
The engine seemed to have seized.
After about 15 mins, it "unseized" itself and I was able to start it.
Again, after 3 or 4 times up and down the lawn, it ground to a halt.
Seized again.
This now is the norm.
From "cold", it will cut for maybe four or five minutes and then
seize.
Someone told me to put 2 stroke oil in the petrol which I have but it
doesn't seem to have done much to help.
Whats wrong here???????
Why does it seize after a few minutes running and why does it unseize
itself.
Why hasnt it done it for the last 10 months?
Is it the engine itself at fault or perhaps a bearing seizing when it
gets hot?
How can I fix this problem please?
Many thanks in advance.




--
kanewesley

Thanks......I did check the oil level....it hasn't a dipstick but has to be topped up to the lip of the filler cap which is towards the bottom of the head.
Can't say 100% what the level was but I have drained the original oil out and replaced with a universal lawnmower oil from B&Q.....Performance of the mower was still the same, stalling / seizing after a few minutes.

How do I check for air flow around the head??????? I thought as it was open to the elements, the ambient air around it would cool it?

Do any of you think the engine is shot?

I wouldn't have thought so as when it is cold, therre is plenty of compression and it runs ok for five minutes.

What if the piston rings were badly worn?.....if the rings were in good condition and the piston expanded, only the ring would have contact with the barrel and would still run.
If the rings say were worn down, and the piston expanded with heat, we now have the full surface area of the piston in contact with the barrel and it may cause so much drag, it stalls the engine.

Is this feasable or am I talking crap !!!!

I had to pull up a pic of your mower (hope I got the right one) I assume it is a common old briggs motor (fixed a few but usually bomb proof). The cooling is a forced air type, there are fins on the flywheel behind the recoil starter, and this is enclosed in a metal shield that bolts to the engine. It is a long shot however I have known grass to build up in this shield and the cylinder barrel fins and effectively block the forced air cooling. I do admit it is a long shot but it certainly sounds like a heat seize problem. It may pay to remove any drive belts to the roller/cylinder blades, this may eliminate a transmission problem. Apart from these idea I must admit I feel stumped.

Atco Commodor B17 Stalling
 

kanewesley wrote:
ferrarif360cs;850939 Wrote:
As Dave said check the oil and/or top it up or replace it with the
correct grade.
And also check it is getting enough cooling air. "Heat seizure" is
pretty common due to lack of cooling. May also pay to check the spark
plug for the colour at the tip, as a too lean a fuel mixture can cause
overheating in extreme cases.
Good luck


Thanks......I did check the oil level....it hasn't a dipstick but has
to be topped up to the lip of the filler cap which is towards the
bottom of the head.
Can't say 100% what the level was but I have drained the original oil
out and replaced with a universal lawnmower oil from
B&Q.....Performance of the mower was still the same, stalling / seizing
after a few minutes.

How do I check for air flow around the head??????? I thought as it was
open to the elements, the ambient air around it would cool it?

Do any of you think the engine is shot?


There is no doubt that the engine is shot. I have never seen an engine
seize without doing major damage. It may run again when it cools off but
it has begun to self destruct internally.

--
Art

Problem solved.......it WAS the engine which was shot......I took it to a repairers and he removed the pull start ass'y
He took hold of the crankshaft which was then protruding and he could waggle it up and dowm by about 8mm.
Because of this "movement" in the crankshaft, the piston could move up and down in a fashion when the engine was cold but when it warmed up, everything obviously expanded and the vertical travel of the piston was now at a slight angle but enough for it to jam.
I got a second hand engine from another repair centre for ATCO mowers for 20 quid.
This has been fitted and I'm almost running to keep up with it at full throttle.
Thanks for your interset anyway....!!!!!