How to clean that mess? (pistons)

clean shop rags will do the trick to keep trash out.if you are going to pull the cylinder might as well check bores to make sure they are round;)

wireman wrote:

clean shop rags will do the trick to keep trash out.if you are going to pull the cylinder might as well check bores to make sure they are round;)

Yep, I'll measure bores. I hope I'll get the suitable tool on this we. If I don't, I start cleaning the cylinder head with the valves still in place to do not deteriorate their seats.

while you have the head off lay it on its side with the exhuast ports pointing up fill ports with solvent and use a blower to blow air around edge of valves wher they seat if you dont see any bubbles in the solvent while you do this your valves are seating ok,swith sides and do same with intakes;)

This is probably stupid, and hope someone will shoot it down quick. Anyhow, recently heard the oven-cleaning trick of leaving a bowl of ammonia in the oven overnight to soften the baked-on carbon crud and enabled just wiping clean with little effort. Sounds to good to be true -- and probably is -- but wondering: how about placing an ammonia soaked shop rag on the pistons, covering it with plastic (zip-loc, seran wrap or whatever) and letting it sit overnight. And the next morning magically wiping softened crud off the pistons leaving them gleaming all fresh as new.
Yeah, I know, just a pipe dream.

Well, I made some searchs on the internet about cleaning that stuff with chemical products. I rarely found references to that solution. I mean, not serious or frequent enough for me to be confident about using it.
I'll try the "usual" way, and if it doesn't work, I'll try something else. IMO, what is really needed is time and care.
Moreover, I've read one shouldn't remove the carbon deposits which are on the upper sides of the pistons. Using a chemical product would probably remove that too.
Anyway, I'll measure everything. It's possible cleaning those parts is a loss of time. I hope it's not, but I prefer to know before cleaning those pistons.

30 yrs. expierence working on air cooled as well as lqd. cooled engines tells me that theres not anything wrong with your motor. way too many considerations to take into effect.
1..have you rode it long enuff BEFORE the tear down to know for a fact it was USEING oil?
2..Did it smoke when you 1st started it and then clear up?
3..Did it smoke after it was warmed up and you accelerated hard?
4..Leaving your choke on too long will certainly make it run rich enough to leave carbon build up alone.
BUT heres the issue as I see it.
You want clean pistons, and to make sure the motor is not useing oil. And I certainly agree now that its torn apart to do exactly that! Find a reputable bike shop and take the head to them. Get a valve job done and take advantage of the tear down and replace the guides with bronze, and valve seals with teflon style. It would not hurt to have this done considering the mileage. Remove the pistons and have the machine shop mic the skirts and look them over carefully. Then mic the cylinder bore. Make sure you can get away with just a light hone. Install new rings and do NOT forget to set the ring end gaps. You would be surprised by doing this just how much better your bike will run, as well as the piece of mind because after this you will know exactly whats been done and when. I am sure everyone would agree there is more to this than just cleaning and LOOKING. EXACT measurements should be taken to repair/replace any defective parts. I hope I have not been brash or rude. BUT you can NOT look at the top of a set of pistons and tell the whole history of the engine. GOOD LUCK and like my dad always said..if its worth doing, its worth doing right!

In all my wisdom....LOL {NOT} Its been my expierence in the last 10 - 15 yrs. they have removed all the chemicals that truely did work for removeing carbon. EPA standards and all that politically correct non sense. Wire wheel with THIN bristols, a descent carburater cleaner, and if you are going to remove the pistons just let the machine shop glass bead them and forget about it. Back in the dat when they sold shops REAL carburater cleaner in a soak tank is the only chemical I know of that worked. Carbon is one of the hardest things to attempt to desolve, so not knowing how your going to approach all this, if your going to leave them in, lower them 1/2 way down, then line the cylinder wall with suspension GREASE then rotate the piston to the top. That seals the rings and helps stop anything from getting down the walls. Get some duct tape and tape up everything you can, then get the wire wheel and go at it. After its clean enough, lower it and wipe out all the excess. Move onto the next cylinder. If your going to remove them, drop them off at any machine shop for a glass bead treatment. DON'T forget to mark which cylinder they came out of. With a small pin punch, with a light touch mark the INSIDE 1 dot means #1 cylinder etc. Just an idea! Personally and I understand I am NOT everybody. I would drop everyhting off at a bike shop to atleast have it all cleaned and machined and put it back together yourself. Your going to spend more time, money, and frustration in just cleaning than they would charge you. And more than likely they can do it better.

when having pistons glass beaded to clean them up make sure to mask off everything except the tops to protect them from glass beads.check the head 1st to see if valves are sealing although a good cleanup and valvejob wouldnt hurt if there is money in budget for it,i prefer the iron guides over bronze myself but thats just a personal preferance thing;) .if the head is still sealing good id say drop the pan check oilpump and throw a timing chain in it which will get you more dependability than a valve job if its not needed;)

On this we, I took some hours to clean the cylinder head :



Example before :


The same one after :


Of course, I didn't touch the area around the valves. I'll clean it with a *LOT* of care after I remove the valves.

Cleaning the cylinder head wasn't difficult, and it took me 2 hours only. I think cleaning the pistons won't be much more difficult.

I notice the exhaust valves were more difficult to clean than the inlet ones.

Post edited by: steell, at: 2007/04/01 17:26

they run a lot hotter than intakes do;)