Pulled my expansion chamber and took a look in the exhaust port.
The piston skirt looks like it has a hazy grey finish on it and the exhaust port has a gooey silver paste, kinda like rubbing compound but no grit and pretty sticky like RTV.
Is this a symptom of sucking sand through the motor?
P.S. I can't see the top of the piston to tell if it's got heavy carbon build up from burning sand.
Is there a chance that water could have a role? That might explain the grey colored substance. Oil mixed with water makes for a Milky Way color. Just a thought. I'm probably way off lol
Is there a chance that water could have a role?
100% positive it's nothing to do with water or coolant.
I've seen this before and I think it's sand coming through the filter and being burnt in the motor but since I can't see the piston crown to confirm I need Jerry to confirm what I think I remember.
What do you have for air filtration and is it possible that some dust is unavoidable? I 'm trying to build a duner w/ an 85' 250. Just curious if my filter is up to par.
You still running that dry flow AEM?
Ill be tearing into mine within the next week or so to inspect.
I got that on my 285 when it's only seen the ice. I had an issue that caused my bike to run hot. I never melted the piston of damaged the bore. Buy it was hot enough to melt the exhaust flange ori GS, the silicone coupler, and and every shred of packing in my silencer. The exhaust port was cover in that same grey stuff. I figure it's what's left after the fuel/oil super heated. Idk. Maybe Jerry will chime in.
You still running that dry flow AEM?
Yes and I got a brand new one last season and I'm running 2 outerwears over it plus I'm used AEM's special "Dryflow" cleaning fluid to clean it and I only cleaned it once in cold water. Did everything to instructions and I know it's passing fine dust (see pics attached), quesiton is how much and is this grey paste a result of the dust burning in the motor?
If it is, it wears the bore and bearings faster which means more pistons and rebuilds so that's why I'm trying to determine the cause of this. So I can stop it, if it's as simple a going to an oiled filter.
This is just under 20 Hours of ride time
I would quickly discontinue using any filter that left my intake looking like that. I never see anything like that using an oiled foam filter.
That's pretty bad. You guys have some fine sand at Glamis.
A lot more coarse where i ride. I've never seen sand like that in mine, but this really makes me not want to use it anymore.
Edit:
Are you certain the boot wasnt cockeye'd or something?
The gray paste is probably in the transfer ports and crankcase area as well. The gray paste is usually powered aluminum mixed with oil. The powered aluminum is ground up piston skirt from sand, dust or any abrasive that makes it way into the engine. The most common path into the engine is through an improperly serviced air filter. In this case, the pores in the dry filter are probably larger than the dirt particles sailing through the filter pores.
Dry filters require an enormous amount of surface area to have high air flow capability if the pores are small enough to catch ALL of the very fine powder. An outer ware is a waste of money on a dry filter because the pores in the outer ware should be larger than the pores in the dry filtering surface. If the outer ware has smaller pores than the dry filter......there is no need for the dry filter.
Damn. I run a k&n with filter skin and I've never had anything like that in my intake.
The gray paste is usually powered aluminum mixed with oil. The powered aluminum is ground up piston skirt from sand, dust or any abrasive that makes it way into the engine.
As I thought, going to try a K&N cotton element oiled this weekend.
The most common path into the engine is through an improperly serviced air filter.
Yes, I wonder if it's lack of cleaning or it just passes sand. This is with 16-18 hours run time.
Here's the new set up, I'll report back how it does
Good stuff to know - I am old school and still run oil'd filters.
I wasn't aware of a dry filter other than OEM paper filters.
The gray paste is usually powered aluminum mixed with oil. The powered aluminum is ground up piston skirt from sand, dust or any abrasive that makes it way into the engine.
As I thought, going to try a K&N cotton element oiled this weekend.
The most common path into the engine is through an improperly serviced air filter.
Yes, I wonder if it's lack of cleaning or it just passes sand. This is with 16-18 hours run time.
Paper filters do not pass dirt when they get dirty, they just will not pass air because the pores that air passes through have a particles of dirt wedged in them.
Foam filters will pass dirt when the filters are run too long. Foam filters will pass dirt after the sticky surfaces on the walls of the airflow passages through the filter have dirt stuck to them. As dirt sticks to the walls of the airflow passage ways, there is less sticky surfaces for new particles to stick to. As the time on freshly services foam filter increases there is a larger chance that a particle of dirt may pass all of the way through the foam without finding a sticky surface.
The gray paste is usually powered aluminum mixed with oil. The powered aluminum is ground up piston skirt from sand, dust or any abrasive that makes it way into the engine.
As I thought, going to try a K&N cotton element oiled this weekend.
The most common path into the engine is through an improperly serviced air filter.
Yes, I wonder if it's lack of cleaning or it just passes sand. This is with 16-18 hours run time.
Here's the new set up, I'll report back how it does
......
Oh man, I would not use the K&N at Glamis. Just like the dry filter I tried (Amsoil Dry) they both ended up passing the fine dust. Maybe they have better filter material now as it was a few years ago. I've settled on oil foam & outerwears. I'll take the lower power output from less airflow for better protection for my engine. Except for breaking my cylindersuzukiquadracerhq
Good luck with what ever you end up with.
Soooo, oiled, properly maintained filters provide the best filtration in sand...
I'm just curious cause my 86' will be finished some day and ready for the dunes. I just don't want to put it into the sand unless its very well protected. It's taken me years to get it rebuilt this far. I'm not about to do something that will make it all for nothing.
Soooo, oiled, properly maintained filters provide the best filtration in sand... I'm just curious cause my 86' will be finished some day and ready for the dunes. I just don't want to put it into the sand unless its very well protected. It's taken me years to get it rebuilt this far. I'm not about to do something that will make it all for nothing.
Yes, that has been my experience whether it is a foam or a K&N filter. Foam air filters and K& N filters operate on two totally different principles and require different cleaning and oiling techniques as well as different filter oils to work the best they can. I have not found the K&N filters to last as long as they are advertised to last. K&N filters are often ruined the first time they are cleaned and few guys oil them properly.
Beware there are some imitation filters that look like K&N filters but they do not use the cotton gauze mesh, they use some type of synthetic gauze mesh.
The filter oil will soak into the cotton gauze but the oil will not soak into the synthetic gauze. The oil does not seem to adhere to each fiber in the synthetic gauze. The oil does seem to stay evenly distributed and provide a sticky surface around each small hole the air passes through.
I had no idea about the K&N knockoffs on the market.
Ok put new set up on including brand new outerwears and made the last trip of the season which as usual came with it's list of $hit breaking
We did manage however to get 6 hours on the new set up and it looks like the verdict is in (at least so far).
Here's the results after 6 hours...pretty dam clean compared to the other one but again this is with 1/3 the time and the element having never been cleaned (that's why I say so far).
Looks like we got some sand past the shrink wrapped hose clamp that I'm using to seal the end of the extra long outerwears so maybe a new seal system is on order but the filter kept it out.
For the 1st trip of next season, I will clean this filter with kerosene then soap then re-oil it and see how it does after being cleaned at re-oiled.
I had very very light dust in my intake. Looked about like your K&N setup. Think it's the difference in the sand/locations we ride.
Guess ill stick with the Dry Flow AEM for now.
