Run with no air filter

[Mickwhitt 4,584]

Hey all.

My friend asked me to look at her mower as it was hard to start.

I started it no problem so I suspect she is just a bit weak lol.

The main problem is the air filter cover and element are missing.

She says something black fell off and got chewed up a while ago!

It's a fairly new mower but it's a DIY store own brand so parts are hard to source. It is a Briggs and stratton engine but I cant find the model on their website. 

I will have a hunt round for a cover but could conceivably make one.

My worry is her running it without an air filter. How long would it take for serious damage to occur? The venturi was lined with a thin film of grass dust so it has been used without the cleaner for some little time. 

[meadowfield 2,570]

not long if it is sucking up grit, it's going to score the bore and ruin the valve seats, over time compression will drop until it fails to start or run

[ebinmaine 67,271]

That's really a question without an answer.

Given the fact that it's already been ingesting some foreign matter it's nearly impossible that it wouldn't have some existing damage. The question is, how much and how serious?

 

I think your best bet is probably just to go ahead and make the air filter as soon as possible and hope for the best.

 

It's either going to run for exactly one more minute, or many many many hours.

[meadowfield 2,570]

I might add even a plastic pop bottle cut down with a piece of oily sponge inside will work well - my dad did it on some old Villiers engines for years!

[Tractorhead 9,064]

Any filter that can be made to fit is better than nothing.

 

when i see those dirt in even if it‘s now maybe just grass, i would give it a cleanup on the whole intake as far as possible.

Get a Aluminum plate 3-4mm and build a adapter for a standart filter that can easily be swaped if clogged 

and a second plate as „cap“ there are 2 screws they can keep the Mainplate with filter and cap together.

 

not the easiest for a maintanance but effective enough to save the Engine from sucked dirt.

 

A womens stocking used as filter pullover helps to keep the filterelement longer times in service.

 

 

 

[Mickwhitt 4,584]

I've managed to navigate my way through the minefield of Briggs and stratton technical data and located a part number. But it's not shown as available. BUT  they might still be able to get hold of one. 

I will see if one is available as it would be tricky to replicate. The air filter housing incorporates the fuel priming pump and crankcase breather. 

[Mickwhitt 4,584]

Nice new air filter and cover obtained from my local mower fitted and all looks ok. 

I dont think there was too much crap sucked into the carb but time will tell.