Ktm 125 Sx Top End Rebuild - Pt.1

OK so I have a KTM 125 sx 2004 and I want to rebuild the top end I don't really know what I'm doing but I got it apart this far I got the cylinder off I got the engine out There's the bike right there You can kind of see it with the light It all came out pretty easy KTMs are really nice to work on Now I got this cylinder I'll see if I can hold it up to the light here There are some score marks, I can kinda catch my fingernails on them So I don't know if they are too deep to get away with just roughing it up with a scoth brite pad Or whether I need to get it re-plated So I'm going to clean that up in a sceond here along with the other stuff I took apart I got the power valve cover Another part in the power valve This is the, uh, exhaust flap or power valve All that stuff bolts on to the head the cylinder I should say right here there's two dowels, or, I'm not sure what you call them that go right there and another eccentric dowel that goes right there all driven by these pieces right here and it's pretty dirty You can see that Pretty gunked up So, I'm going to get after that with some carb cleaner I think and some of these other metal parts I think I'm going to tey, maybe, uh Oven cleaner But not this aluminum stuff because the lye in there i guess will eat away at the aluminum So I'm going to start with that Ok, I also bought some goodies here I got this nail brush I can use that to scrub up some of these parts the ScothBrite pads were recommended for finishing up the Nikasil coating on the cylinder See how that will work Bought some latex gloves, don't know if I'll use those, but I got them And some oven cleaner It's actually pretty cheap Along with this old trusty little toothbrush like thing, and, uh pail of carb cleaner over there should be able to do this all right the only thing I'm worried about are those scratches kind of have a feeling I'm not going to get away with just, uh, Just scrubbing them out I think it's going to need a re-plating OK I'm going to dump all these metal parts into this tin can And spray them down with some Oven cleaner See if that get's all the grime off These have o-rings on them probably shouldn't get oven cleaner on that this hose wont get oven cleaned that part is probably ok these guys those dowel things I was talking about little gear on the end little valve I guess they are valves probably, not dowels not even that bad and this is this goes up and down it lifts the power valve I think that is what the eccentric roller on the top must engage in that is this guy see it's got that eccentric centered little pin there and some bolts probably all go in there good stuff now this guy, the actual power valve I'm assuming it's steel just by it's weight give it a go too this guy is all blackened up pretty sure this piece is aluminum just because, yeah it's all one piece, so that's aluminum OK so I have a KTM 125 sx 2004 and I want to rebuild the top end I don't really know what I'm doing but I got it apart this far I got the cylinder off So I'm going to clean that up in a second here along with the other stuff I took apart I got the power valve cover Another part in the power valve This is the, uh, exhaust flap or power valve All that stuff bolts on to the head the cylinder I should say right here there's two dowels, or, I'm not sure what you call them that go right there and another eccentric dowel that goes right there all driven by these pieces right here and it's pretty dirty eccentric centered little pin there and some bolts probably all go in there good stuff now this guy, the actual power valve I'm assuming it's steel just by its weight give it a go too this guy is all blackened up pretty sure this piece is aluminum just because, yeah it's all one piece, so that's aluminum that won't go in this cover plate might as well go get a coating like to do these axels these are the power valve axels I might pull these o-rings off first Sorry I got that too close to the camera there I've decided to put the latex gloves on for this part even though I'm pretty sure this oven cleaner will just eat them up if it touches them uh huh directions preheat that's not going to happen wear long rubber gloves latex is what I got spread liberally for ease of application remove oven racks don't have those open cap to see instructions below hold can upright 5 to 10 minutes then wipe with a wet cloth and sponge rinse frequently for heavy soiled areas work longer quick, easy, alright! I think this will be OK alright give a shake and, a little sprits I'll let that sit OK, after a bunch of scrubbing later I got the parts pretty cleaned up they are just sitting in a bath of carb cleaner right now to just get the last little bits off that power valve was really grungy Uh, next step is to take a ScothBrite pad to this bad boy see what we can make happen there And, if everything goes good I can start putting her back together That will be sweet Alright I got after this cylinder with the ScotchBrite pad It seemed to de-glaze it a bit see if I can get it in the light here but, uh, there's still some marks that I'm kind of concerned about Kind of see them there I don't know if they are Bad enough that they'll cause some issues or whether it's typical for something like this Just, because I can still see them after going after them with the ScotchBrite pad I'm thinking I gotta I gotta get it re-plated, but I really don't know Next think to check is the bore dimensions see if they are on spec according to the manual and if they are maybe I'll just try it with this new piston if it blows up it blows up OK, it's a couple days later I took that cylinder to some guys in town and they told me it could use a honing, it it probably doesn't need a re-plating So that's good So I'll get that back in about a week or something In the mean time I cleaned up all the power valve parts scrubbed them all up with the, uh, oven cleaner and carb cleaner I don't know how well the oven cleaner worked in this case, um the carb cleaner and a lot of scrubbing seemed to work just as well as anything else. I didn't replace the o-rings on these axles I'll grease them up when I put them in but if they leak I'll just have to swap those out with some o-rings I checked the o-rings I have hand, I didn't have any the right size the head, I took the head up and cleaned up the inside it looks like I could go over it a little bit more but it should be just about ready to go uh, the power valve cover, it's all cleaned up it's ready to get thrown back in there Um, some other things I did I broke the fender on the bike before so I took all the parts and the bike and everything to the car wash and cleaned them all up and I put the new fender on the subframe So that's ready to go when the bike gets thrown together I washed some of these exhaust parts too So those are ready to go I got to clean up this old air filter It's pretty dirty I bought some new air filters and, put those together, I mean I oiled them up and put em in some zip lock bags so they are ready to go for my trip I cleaned my carburetor up That is what I was doing most recently I cleaned the carburetor up so it's ready to go I, Uh, I just bought, or I just ordered some jets online So I'll have the complete jet kit for that guy That'll be good and some other little nuts and bolts I was missing So the bike should be just about ready in about a week and a half I should have this all put back together I assume That's it for now Um, I'll update you when this stuff goes back together