Pulled The Cylender, found buildup on wall

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IrishEKU

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Pulled the cylender an found build up on the wall. 12:00 being exaust this was at 10 or 11 o'clock, what would cause a piston to "Shead" or leave deposits in a certain area?

Overheating?

I did get a lower ammount of coolant than expected when I cracked the jug.

The Cap was immaculate and the jug is smooth aside from a one inch square area near the port. It is raised and can I use a Hone to remove the depsit or is it time to punch it?
 
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marcusgunby

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You maybe able to hone it clean-what have you to loose by trying?Any pics would be helpful.Until you find the cause then dont waste any money rebuilding it.A loss of coolant is very suspect.
 
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viking20

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If its aluminium build up,I believe it can be removed with acid,never done it myself though,and dont know what kin of acid to use.Anyone?
 
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IrishEKU

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Correct Marcus, I have narrowed it down and I need to split the cases :(
After a good nights sleep, I reaproached it this morning and the engine failure was due to a couple of things though I suspect one was existant for awhile. I'll have pitures tomorow when I get home.

Here we go; After the last ride I took I noticed oil around the power valve cover while not unusual on my make and model there was water mixed in. It had been raining so I chalked it up to the elements. Wrong answer, while tearing down to get to the piston I noted that there was oil and water preasent in the case and coating the crank. Water? yup existing problem 1 found, leaking impellar seal on water pump. Number 2 is the one that hurts and leads to the posted question. Water/oil in the case can only come from one place and thats the oil seal on the crank shaft and that leads to the final one, the "shedding" piston, with that nasty mix though not much but enough to shorten the life if what I had been suspecting as a worn lower bering on the conecting rod, was causing the pistion to "slap" lateraly against the cylender walls. With the jug off the lateral movement of the piston is close to 3 times what it should be and that is 0.2-0.7 according to the manual :ugg:

Lesson learned, I should have done this when I rebuilt the shock but then again I always seem to have to learn the hard way.

Thanks,
 
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FFRacing11x

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Nov 23, 2002
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If your water pump seal is leaking, you will find that your Trans oil will be contaminated and milky looking. A bad water pump seal will NOT allow coolant into the crank and cylinder areas!! The only ways for coolant to enter the crank/combustion areas is either by the head or base gaskets(depending on models). IF your crank seal was indeed bad allowing contaminated transoil/coolant to be sucked into the crank area, the oil and coolant would not be separated where you could actually see coolant. If your clutch side seal is indeed leaking, you would also see excessive smoke from the exhaust.
It seems you have several problems going on here but they are not all related.
I hope I understood your posts correctly. TW
 
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IrishEKU

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Thank you for adding what I took for as irrelavent and understood, I won't do so in the future.

Cheers,
 
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IrishEKU

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Marcus, here are the requested pictures:

As you can see the cap is smoth and no pitting has occured, however there was a little surface rust on the jackets.
 

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IrishEKU

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Here is the cylender, the build up is smooth and barley felt to the touch, I would have to say somewhere in the neigborhood of .01-.02 mm?
 

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IrishEKU

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Here is the piston, the grooves are easily felt and the ring is barley worn, hardly discernable without a micrometer(I misplaced mine and can't find it).
 

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IrishEKU

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I don't know if you can see it in the picture but there is a slight cup or lip to the piston, like it dragged over something on the downward stroke:
 

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marcusgunby

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that is a strange thing to happen-a few others like eric may be better judges of the problem.I dont see any signs of detonation.It does appear that the damage was done to the piston crown on the downstroke.Too much side to side play in the rod??im guessing here and i dont think i have the answer:(
 
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IrishEKU

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Marcus, not to worry mate, I am sure the damage came from the play in the lower bering.

Although I would like to hear what Eric has to say on the subject.

On a posative note there is no up and down play on the connecting rod so the shavings never came from that, just the piston shedding on the wall. Another check on the plus side is the coloration on top of the piston, I installed that one in June and after 5 months and close to 50 hours of hard riding it looked that good. I will post a picture or two of the one I removed, the crown has a thick coating of carbon and the top of the ring(Facing the exaust) is worn to half it's original thickness. That is also with stock jetting and 40:1 Motul800 and 93 octaine pump gas. Even though it was a mosquito fogger it looked like that. I also need to send the pipe off, I never really noticed it before but just behind the flange and down into the expantion chamber there is a build up of carbon. That had to add to the "Smoke" by catching some of the residual mix that didn't get burned and holding it in the pipe. I am curious though, could a peice of carbon get heated and cooled enough to gouge a hot aluminum piston? The original piston that came with the bike was OEM and steel, the one I just removed was a Wiseco STD bore.
 
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jmics19067

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one thing that look odd to me is that you can't see a complete mark from the fire ring of the head gasket all the way around the head. Unless it is an opticle illusion from the picture use a straight edges and double check that the head and cylinder are indeed flat. Right around the two bolt holes at the 4 oclock and 8 Oclock position in your picture of your head is that where your dowels are? Are the dowels two tall for the head to sit flat? Also is your head gasket meant to go on only one way?
 
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jmics19067

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ooops sorry just realized it was an oring but still I would think that there should be some type of mark all the way around the head
 
D

DEANSFASTWAY

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Hi IRISH Howsit goin ? From what I can see in your pic of cylinder it looks to me like all the plating is worn off around the EX port and part of it may have stuck to the new ring/piston . See the gray area around the exhaust port that isnt as shiny as the rest ? Thats what it looks like when it needs to be rechromed . With wear in this area the rings will ride further into the ex port and rattle or snag the P/V . The P/V stops on that drum type system wear out also and the valve can protrude into the bore and snagthe rings also . It also looks like it is worn out near the top of the cylinder where the rings roide the highest part of the stroke, These and the intake side are the areas of most common wear. What did the piston that came out before you put the WISECO look like ? Wiseco forged pistons also usually require a little longer and more careful warmup than cast stock piston due to different expansion rate of forged aluminium.Looks like you need a replate and new piston assy , but you know while its apart you might want to rebuild the cranky& seals & stuff as a maintenance practice. Then your motor will be fresh and you could have it together about the time the cyl comes back from the plate shop.Actually you are probably not seeing the piston "shedding" you are probably seeing the plating stick to the piston when it etches off .Nothing lasts forever my friend but if put the attention to it now youll probably get a few good seasons out of it it you do an overhaul . GOOD LUCK
 
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IrishEKU

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Originally posted by jmics19067
ooops sorry just realized it was an oring but still I would think that there should be some type of mark all the way around the head
Click to expand...

jmics,

I would think so too, but there are no dowles at the head area, there are only dowels in the cap. I was careful on the spec.'s for the head tourque wise and all where to spec. Your answer leaves me wondering, "Fire Ring", what is that? Granted I have worked on engines but that is 4 stroke and Diesel, not 2 smoke stuff. Please explain.

At 4 and 8 o'clock are head bolts. Behind those bolts are the carb. Would that have anything to do with it?

If so I have a warped head or Base. Inadequite tourque or head preperation.

The bike would wet foul from time to time but I chalked that up to leaving the fuel on or my improper starting proceadure. After riding Big Lou's KTM, I know mine has quite a few problems that need to be taken care of.

New parts to order:
Reeds
Jets(Have those now....both 1 and 2 #'s leaner ;) )
Pipe(Expantion chamber needs cleaning like my last dental appointment! :( )
Clutch Plates(On Hand and ready to install)
Honing(This week)
Lower Bering and rod(in the mail)
Top End(When the lower part gets here)


Sheesh! Aside from Eric's polish and porting, what else should I do? MECHANICALLY! (I already have an order in for a # plate and new side panels.. :thumb: )
 
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IrishEKU

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Dean,

Thanks for the reply! I share the same view and hope Eric will reply. I also think the plating is worn, but from the previous piston change and the wear on the ring( I will post a pic) I belive the coloration that you are talking about is what was left of the former OEM ring and piston. There is no change what so ever in the bore near the exaust valve just color, I may be wrong but I didn't notice it. Granted that doesn't account for my current failure, it was my fault not replacing the lower berings the first go around. Currently the failure seems to be because of my inadiquit warm up, not replacing the lower bering when I should have and water making it in through a bad filter which I strongly suspect hence the clean 'freeze' pulling the cap(Ruling out the impeelar seal).Or should I say the last of the two former? :ugg: The cross hatching on both pistons is non-existant and on the cylender too. Actually there is none on the cylender! :(

Granted when it comes to 2 smoke maintenance I am a novice but, I know that an aluminum piston, leaving deposits on a plated wall has to have something to do with heat and FOD (Foreign Object Damage). Wear like near the Exaust port is accepted. Build up isn't.

Any and all Help is appreciated :thumb:
 
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Rcannon

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Dumb question time....Is this a buildup or an area that has worn throught the liner? Next question..If this is smootherd out, is the cylinder ok to use without re-plating? Thanks!!!
 
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IrishEKU

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Rcannon,
The only dumb questiom is the one that isn't ask'ed.....

It is build up....

The cylender as is will be o-k to use after honing and a new top end, BUT!

The reason for the wear is a worn lower end. That is what I need to replace.

Good Luck,
 
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Rcannon

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I understand what you said...but , how can something that is wearing out have a build up on it? It just does not make any sence to me.

I saw a very worn out CR 125 cylinder at the local machine shop. they showed me where the liner had worn through. I swear, 1/16 of an inch of material was missing where the liner was. It was very strange and made me realize just how tough this "lining" material is.
 
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jmics19067

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Jan 22, 2002
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"Your answer leaves me wondering, "Fire Ring", what is that? Granted I have worked on engines but that is 4 stroke and Diesel, not 2 smoke stuff. Please explain."

first sorry about the quotes but any how. What I meant about the fire ring would be incorrect because there is no head geasket. That would be the metal band that would go around the cylinder bore in a composite head gasket.

On the picture of the head {cap?} there are five holes for the studs to pass thru those aren't dowels stuck in the head ? right where I can't see an even mark all the way around the cylinder bore


I just thought of somethig bizarre. would it be possible for the cylinder to warp? lets just say that the cylinder is almost completely surrounded by water except for where some extra matierial is used to support the power valve area. Is this the area that you have your raised spot in?
 
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