Air filter disintegrated, Best course of action?

[qwerty1234]

Friend purchased a WR400 in pretty good condition, needed a few very minor things but for the most part, everythings there and working well

Everything except the air filter.... it's not the very first thing I checked and the bike has been ridden by myself and some other prospecting buyers. The filter had disintegrated and most of it sucked into the engine by the time I got the seat off to check it. The inside of the carby was stained slightly yellow, cleaned it up as best I could. Jets and passages are fine, starts easier now and runs just perfectly. But who knows how much dirt and fine particles got through the engine

 

I live in Australia where we have some very harsh dust particles. As of right now the bike is running fine, nice and strong with no visible smoke (yet). It was however ridden home (about 30km of tarmac) and thus sucked a lot of unfiltered air.

I'm about to do a compression test to see where it currently stands, but as for standing it'll still happily hold my entire weight on the kickstarter (90-95kg) for at least 5 seconds without using the decomp.

 

Disconnect carby, get it on intake stroke and blast through spark plug hole with compressed air?

Run upper engine cleaner through it?

Pull the head? (it is only a cheap buy so really...)

Just ride it and not care?

 

[manotickmike]

Change the oil and ride. Any damage is done, any remaining bits and grit are in the oil by now.

[FORMA MOTO]

Open wallet

Purchase new air an oil filter

Close wallet

Install parts

Clean oil screens (depending on year) <<< your year is ESSENTIAL

Fresh oil

Ride

[qwerty1234]

It's a 2000 model. Does it run a screen?

 

Already got new air filter on there. Don't have oil and there's a ride scheduled tomorrow so it's going to have to put up with 1 ride (the oil thats in there looks very clean)

Didn't get around to doing the compression test, but noticed it would smoke a bit when idling high with the choke on. So I guess some damage is done

 

I'm more interested in what are the implications of a dusted engine? I've done it (by accident) to a 2 stroke before and it scored up the cylinder, that was riding on a very dusty trail however. Ultimately it didn't cause any problems other than crap low end performance and bugger all compression when starting. But not sure about high performance 4 strokes, whether it's liable to cause additional damage by continuing to run it, i.e. develop piston slap

[FORMA MOTO]

If you have not been inspecting your air filter often enough to know if it's disintegrated or not, you damage was done a while ago.

[flyandride]

Inhaled dirt is hard on valves, especially titanium.  I think the 400 had steel, so you may be in luck.  If the bike gets to where you don't need the decompression lever to start it, the valves need attention.  

[qwerty1234]

If you have not been inspecting your air filter often enough to know if it's disintegrated or not, you damage was done a while ago.

 

Note the bike was purchased just recently, and was purchased with a disintegrated filter. How long its been that way is a mystery but was the sellers fault. Nevertheless the engine appears to hold a lot of compression, as I said I can stand on the lever for at least 5 seconds or more without it budging

[FORMA MOTO]

Note the bike was purchased just recently, and was purchased with a disintegrated filter. How long its been that way is a mystery but was the sellers fault. Nevertheless the engine appears to hold a lot of compression, as I said I can stand on the lever for at least 5 seconds or more without it budging

 

I don't think you should worry about it, past clearing all debris out the screens and doing normal maintenance

Anything that fragile will be consumed by the motor in a non-destructive way.

[MANIAC998]

The dirt particles that have made it into the engine, are now in the oil. Whether or not the oil "looks" clean, I personally would change it. Why wouldn't you want those dirt particles removed from the engine?