OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines Bad Air Filters Destroy Motors

This piston is from a two year old McCulloch BL\150 blower,
looks like dirt has been getting past the air filter resulting
in a badly damaged piston.
Now i know why it has no compression, it pays to check your air
filters regularly,especially if their crappy foam ones like this.
If anyone needs any parts for this model blower let me know.

gmax,

That looks more like lacking oil in the fuel mix as it is badly scored all over.

Bruce,

This came from a lawn mowing contractor, the other 2 stroke tools
i bought from him were fine. There was 2 stroke fuel in the tank
when i bought it.
There was a lot of dirt inside the air intake in the carby, which can only get there by getting past the air filter. I prefer the
nylon flock air filters rather than the foam ones.
But this is a low end hardware shop blower so poor quality is to
be expected.

Gmax

There is definately some heat exchange on that piston.

I agree there is definately dirt ingestion, as there is light scoring across 180 degrees on the intake side of the piston, and from what you say gmax dirt ingestion was definately a problem. Dirt wont cause heat though, and with the discolouration in the piston there was another problem for sure.

My guess (common on this unit) is loose cylinder bolts, causing a partially loose cylinder which causes lean running (hence the heat)and also allows extra dirt ingestion to boot! It may have also been lean mixture settings, but there is defiantely heat exchanged in that piston

Gmax you are so right to highlight about air filters. It definately pays to wash and re-oil air filters correctly. The example shown above is a classic example where you can see where the dirt has by-passed. Was there oil in this filter foam? (for the untrained reading this, all foam filters are useless unless they are oiled)

MST, The filter foam was dry ,the cylinder bolts were tight but the
carby could have been running lean.
Here is another photo of a damaged piston from a poulan 2450 chainsaw. The air filter is also the foam type which was dry.
The last owner spent $120.00 on a new piston & barrel then sold it
with a chainsaw case on ebay.
I bought it for $50.00.
Once i modded the muffler and fitted a decent chain oil pump,it goes
very well for a poulan.

gmax is that the exhaust side or the inlet side damaged because if it is the exhaust side that tells me that it does not have enough oil mix.

As to the air filter foams they should have oil in them. The oil is to catch the dust.

Bruce, That is the exhaust side, the inlet side was damaged but not
as bad.
It seems unusual that poulan would have chrome plated pistons rather
than chrome plate the barrel bore.

Gmax

gmax,

Below is a one page (picture and description) of four that I will be uploading to the parts list and manuals area of the forum soon.

Bruce,

Thanks, that makes interesting reading, wrong fuel mix seems to be a common way to destroy a motor, but a suppose people will only do it once

gmax you also want to watch your high and low speed mix as that can cause damage as well.

Bruce,
I keep them slightly rich rather than have them running to lean,
i learn from other peoples mistakes.
Tomorrow i pickup the Snapper ride on,now i have made room in my shed for it.
Then the restoration begins.

gmax,

Can you post a picture before you start the resto please. I think that I have at least one snapper ride on manual somewhere which I can upload to the parts list and manuals area.

Found it:

Bruce,

I will post photos before i start, that snapper manual picture looks
nothing like my snapper, anyway all going well i will post
photos tomorrow night.

gmax once you post the picture I will see if I can locate the manual as I still have some contacts for snapper but it could tak a week or two.

Ok,thanks Bruce that would be good.