Pics of my top end

[BadA$$440]

I thought i would take some pics as i tear my top end off.

[BadA$$440]

Is all that carbon normal? Maybe thats why it was smoking so bad.

[BadA$$440]

Cam, bearings and sproket

[BadA$$440]

I wouldnt even think about taking it apart with out this...

[BadA$$440]

forgot the pic, srry

[Extremeracer167]

well the only one ive seen apart was mine, and it didnt have that much carbon built up at all. There was some, but not that much! Ide assume the reason it was smoking real bad was becuase of blow by, from it needing to be rebuilt

[BadA$$440]

Piston

[BadA$$440]

Last pic

[BadA$$440]

Originally posted by Extremeracer167
well the only one ive seen apart was mine, and it didnt have that much carbon built up at all. There was some, but not that much! Ide assume the reason it was smoking real bad was becuase of blow by, from it needing to be rebuilt

So all that carbon isnt normal? Ive had her for a year n a half and this is the first time gettin her top taking off. What would cause the carbon? rings?

[Extremeracer167]

not riding it hard enough;) lol no but alot of it can come from the oil u run. Or like i said, the harder u ride it, the cleaner it stays. i didnt have that much when i ripped mine apart.

[Mxbubs]

Relax. If you ride it hard even just on weekends that is normal. I would even speculate that the type of fuel and motor oil would contribute to this. I would replace the rings. If your cylinder doesnt look pitted and chipped, I highly doubt it will be necassary to bore it over to a bigger piston. This is a four stroke, and will run longer than a two stroke before it needs to be bored over. When you change your rings, make sure you put them in right, and make sure the cylinder will slide over them, if you dont have them set just right, the cylinder wont slide over them, DONT FORCE IT! It helps if you have a piece of wood to place between the crank case and the piston, this will keep the piston and crank from spinning when you try to push the cylinder on. Get someone to set the cylinder down, while you take a flat head screwdriver and push the rings in, allowing the cylinder to slide over them. Thats it! Good luck.

[BadA$$440]

Thanks BUBS, i have done a 2 stroke top end before so i know how to put the piston and cyclinder on, im just new to the valves, timing chain and cam but its not that hard if you have a manual. Im taking the top end apart to put a 416 and some other motor work in it.

[AtvMxRider]

what kind of gas are you using? That could play a part in all that carbon.

[BadA$$440]

its 92 or 93 octane

[AtvMxRider]

Is it jetted right? It might be alittle rich.

[JabberJaw]

Dang...and I thought I was going to see hooters!

[kc 300EX]

I tore mine down just before school satrted, and I had about the same amount of carbon as you, I found out it was because of a gasket, a metal one had split and oil was getting through there. I replaced the top end pretty much by myself with no manual and almost no help(except for this site and 2 issues of dirtwheels) Didnt do too shabby

[Scott400EX]

I tore mine down last weekend and it looked about the same maybe a little less. but it comes from running rich. once ur jetting is right and all it should be a lot better

[BadA$$440]

Originally posted by JabberJaw
Dang...and I thought I was going to see hooters!

I was going to title it "Pics of my girl with her top off" but i didnt want the mods gettin mad.


Thanks for all the info guys, i think all the carbon is from running a lil to rich but atleast its to rich instead of to lean.

[methyman]

I agree. I rather the motor be a little rich that too lean.

[Mxbubs]

I dont want to sound like a know it all, but to assure you if you need any help, I split the cases on my 99 ex 3 times.

Then I got a YZ!

Seriously, if you have any questions, pm me.

*tip* I hate putting steel bolts into aluminum, be careful you dont strip any of those 6mm bolt holes.

[Mxbubs]

Oh yeah, and get you a magnet on a stick, you will need it after you cuss out the timing chain cause you drop it and cant get it back up.

Oh yeah, be esp. sure you tighten down, and locktight the cam sprocket flange bolts, or they will back out, the bolt heads will rub the head of the motor, make the cam slow down on a hi rev, jump time, send a valve thru the piston, and possibly bend your crank. I only know this from hear say..........hehe:D

No wait, that happened to me!

[BadA$$440]

haha, thanks for all the tips bubs, i can use them. I havet droped the cam chain into the case yet (knock on wood )

What 6mm bolts are you talkin about? The smallest bolt i had to take of is 8mm and there were 12 on the valve cover and 2 on the side of the cylinder

Got any more tips Bubs?

Those are the 6mm bolts and they have a 8mm head.

The carbon is most likely due to running a little rich, but can be from oil getting into the cyl also.

I have had my motor apart too many times and the one thing that was obvious is that when it was a little lean the carbon buildup was allmost non existant.

About 5 rides before the last teardown I had gone to a larger MJ and it was too much and this time there is allmost as much carbon as you pics, well maybe half that but its still a lot compared to nearly none the time before.

And the most important thing that is missing here is a torque wrench, and I have never heard of anyone doing damage to the aluminum mating parts when they used one.

[OutlawEX]

looks like she is a lil rich

[YZROOSTINYA]

mine was like that before the 416, too rich

what cam did you get, my stge 2 hc is awesome, very impressed

[BadA$$440]

Im getting the TC Gncc cam. Is the main jet under neith the carb and you have to remove like a 12mm bolt/plug? If so, then it says i got a 146 main jet and i only have a pipe on right now.

[YZROOSTINYA]

it prob has a dyno jet main jet in it, 148 is stock. dynojets are larger than the stock jets for the same number. so a 146 is prob like a stock 150 or 152.


you needa 6mm socket to pull the main from the bottom of the carb, and a 17mm to pull the cap. i had to go to a stock 170 main, drop the clip one on the needle and a 42 pilot. i run 6 filtered holes in my lid, full e-series with 12 discs and stage 2 hotcam with 416 je 10.8:1