dirt/rust in cylinder from removing spark plug, sigh

In the process of checking my valve clearance on my '06 yz450f, I think I dropped dirt/rust on the piston through the spark plug hole. Yea. After reading a few threads here, I realized I should have blown compressed air through the leak hole on the cylinder, but hindsight is always 20/20.

I know this is bad, and Im leaning towards removing the head to clean, but is this avoidable? Any other tricks?

Yea, I know...:smirk:

Thanks for any advice

If you didn't drop a bag of sand in it, don't worry, it will not hurt the engine and probably blown out on first start.

What is the cylinder leak hole? Didn't hear of that until now... :smirk:

sorry, hole is on head.

I cant see how crap will just blow out. Seems like I risk scratching cylinder or getting grit pinched between valves and their seats. I dont think a lot of sand fell through, just a little dirt and rust, but with all the tight tolerances I would think anything in there would be a cause for alarm. Am I being paranoid? Should I just take the chance it will blow out?

Thanks

Do you have a small shop vac?.

Or a 2 stroke? ( just kidding)

The cylinder leak hole is on the right side of the bike and lets any real water that gets in the spark plug shaft get out. It doesn't do much to prevent the spark plug from rusting, even in Arizona.

sorry, hole is on head.

I cant see how crap will just blow out. Seems like I risk scratching cylinder or getting grit pinched between valves and their seats. I dont think a lot of sand fell through, just a little dirt and rust, but with all the tight tolerances I would think anything in there would be a cause for alarm. Am I being paranoid? Should I just take the chance it will blow out?

Thanks

Crap will be blown out on the exhaust stroke. I think you worry too much. If you let the engine sit for 2-3 months in winter and the inside of the cylinder rusts and you start it up in the summer, where does all the rust go? Does it kill the engine? No.

Crap will be blown out on the exhaust stroke. I think you worry too much. If you let the engine sit for 2-3 months in winter and the inside of the cylinder rusts and you start it up in the summer, where does all the rust go? Does it kill the engine? No.

What part of your cylinder rusts when the bike sits?

I know mine, and pretty much most all competition bikes made for the last 15 years or so (give or take a few) don't have cylinders that will rust. And if they did, you can bet your rings and the rest of the engine wouldn't last much after.

Anyway, if you have your valve cover off when this happened, slowly rotate the motor by hand in whatever direction needed to open the exhaust valves. Blow some air through the spark plug hole and most if not all will come out the exhaust. Keep a good amount of air flowing for a few seconds.

Of course, you could take the head off.

pretty much most all competition bikes made for the last 15 years or so (give or take a few) don't have cylinders that will rust. And if they did, you can bet your rings and the rest of the engine wouldn't last much after.

Exactly. Maybe my example was a little bit "too much", but it was just to give some confidence to the OP. Yes I know that cylinders are made of alloy or cast (font) and they don't rust, but for ex. also my hobby airplanes little 2 stroke engines cylinder always have in spots a very fine layer of rust after sitting in the winter break. (surface rust)

I just wanted to point out that engines are not so sensitive and a little bit of dust falling in it is not a reason to tear it apart.

My comment was in reply to your statement of it even having surface rust.

These motors will not rust, they have aluminum cylinders plated with Nikasil. No rust here.

In the process of checking my valve clearance on my '06 yz450f, I think I dropped dirt/rust on the piston through the spark plug hole. Yea. After reading a few threads here, I realized I should have blown compressed air through the leak hole on the cylinder, but hindsight is always 20/20.

I know this is bad, and Im leaning towards removing the head to clean, but is this avoidable? Any other tricks?

Yea, I know...:smirk:

Thanks for any advice

I just always use a Golf Tee to plug the hole while washing the bike - this keeps some of the moisture off the plug(which over time does rust). Before removing the plug I spray air into the hole with the cap off or spray contact cleaner into the plug hole draining out of the weep hole then blow air to dry - depends on how dirty it is. Some debree will always fall into the cylinder

dont worry about the small stuff....

I wouldnt recommend using an air compressor since the dirt is most likely just sitting in the top/middle of the piston. Using compressed air will just distribute the dirt all over. I would take a length of hose as big as will fit down the plug hole. Use duct tape to attach the tube to the hose on a shop vac and stick the hose down on top of the piston and suck the junk out.

Also, I use WD-40 or Silicone spray to coat the spark plug/boot area everytime I wash the bike. This will cause any water to poor out the drain hole and leave a coating that will prevent rust. :smirk:

Also, I use WD-40 or Silicone spray to coat the spark plug/boot area everytime I wash the bike. This will cause any water to poor out the drain hole and leave a coating that will prevent rust. :smirk:
I don't recommend that. At least not with WD-40. It's just a poor choice for use either on electricals or as a rust preventative.
I don't recommend that. At least not with WD-40. It's just a poor choice for use either on electricals or as a rust preventative.

WD-40 IS a rust preventative (stands for Water Displacement Formula 40) I have used it for years as one, mostly after I clean my chains or bore a cylinder. Never had a single thing rust while protected by it.

Silicone is better for electrical connections, especially the dielectric grease version, which is what I use on all my spark plug connections. It also works great for any metal to rubber pipe/hose clamp connections as an "anti sieze".

I would duct tape a scraw to your vacuum cleaner and use it to suck out the dirt/moisture.

WD-40 IS a rust preventative (stands for Water Displacement Formula 40) I have used it for years as one, mostly after I clean my chains or bore a cylinder. Never had a single thing rust while protected by it.

Silicone is better for electrical connections, especially the dielectric grease version, which is what I use on all my spark plug connections. It also works great for any metal to rubber pipe/hose clamp connections as an "anti sieze".

WD-40 displaces water very well, too, but it was never originally intended as a rust preventative. It is mostly solvents, is slightly conductive, and will almost entirely evaporate. It may work in the Nevada desert, but not within 15 miles of any coastline. I guarantee from years of experience that an iron or carbon steel part "protected" by WD-40 and left exposed to shop or garage air in San Diego, even in a tool box drawer, will rust within two months unless retreated. Almost any machinist will have had similar experiences.

And, of course, it's the plug hex that rusts, not the boot.

Dielectric grease or silicon sprays intended for HT circuits is a good idea, though. It keeps the boot from sticking to the plug insulator and making the thing more difficult to pull off than it needs to be. They also provide a non-evaporative coat of protection for the insulation.

It may work in the Nevada desert, but not within 15 miles of any coastline.

Good point, next to the Sea, even plastic will rust (sarcasm)!! :smirk:

I would use straight grease (or if you can get Cosmoline) if I was in that type of climate...

I would use straight grease (or if you can get Cosmoline) if I was in that type of climate...

There are a number of commercial products that actually do work, WD-40 just isn't one of them.

Thanks for info, everyone. Ill try "shop vac/straw" trick and sleep easy.

Golf tee and silicone spray are on my list...

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