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View Full Version : Valves hitting top of piston.. everythings set right



CodyRosa
11-21-2013, 02:15 AM
So I have a 10:25:1 Wiseco piston in my 200M cylinder. The motor ran just fine until I was offered a 200x head (old one had all threads stripped on everything) .. and I ended up buying a 200x cam as well. Well I put everything together to find out my intake valve was hitting the top of my piston. Checked top of piston and there was a mark in one of the indents. Found out the piston was 180 off. Wiseco said to put it one way well it was wrong because the smaller indent was on the intake side (intake valve is 2x the size as exhaust) so I swapped the piston. Put top end back together AGAIN and its still hitting. Timing is spot on, cam shaft was put in right, valves are adjusted right, everythings torqued right.. i've tore this top end apart plenty of times and put it back right and always had it start 1st to 2nd pull EXCEPT this time.

So something lies between the 200x camshaft... or the 200x head and I can't figure it out. I still have the old 200M head and 200M cam if i need to try that just to make sure.

Are the 200x valves larger OR do they drop further than the 200m head? Does the 200x cam for whatever reason make the valves drop further....

Thanks everyone

CodyRosa
11-22-2013, 02:50 PM
.. anybody? I still haven't figured it out. I loosed the valves a ton and it just got louder, I then tightened them up and it quiets it down some but its still hitting. Both sides hit. I'm only turning it over by recoil not actually running the machine.

09RappySE
11-22-2013, 05:28 PM
If you are sure everything is right...you may need to machine the valve reliefs deeper....have you clayed it up to see what your piston to head clearance is? I don't know what it should be on that bike, but I am sure someone here knows.

CodyRosa
11-24-2013, 06:16 AM
what do you mean clay it up?

Yup I know for a fact the timing is correct. Valves are spot on. Valves are not bent. Timing chain is not wore. This motor ran just fine until i put a 200x head on it instead of the original 200m.

09RappySE
11-24-2013, 09:18 AM
Claying it up is a method of determining what you clearances are, you remove the head and place it in the valve pockets and top of the piston, you don't need to cover the whole piston, then install the head with gasket, torque it down and crank by hand through a couple cycles...then remove head carefully remove clay and mic it out. I actually like to use tootsie roll because it is greasy and removes easier but you get the idea.

atc500x
11-24-2013, 09:36 AM
The 200x and other 200 use the same valves,
If I'm correct the lift of the 200x is the same as other,but duration is different.Did your 200x cam is stock?
Dont removed head,just swap the cam,can be done without loosing anything or removing valve cover.You have maybe a highlift cam....???
The 200x head been shaved?

CodyRosa
11-24-2013, 12:21 PM
That claying thing sounds quite easy. I may try that if i can get some clay. I ran a 200m cam but then bought a 200x cam from a member on here. He said it was just a 200x cam. I also bought the 200x head off a member here and he to said it was just a 200x head and never mentioned if it had been shaved. I'm going to have to ask him. Weird part is.. i have a thicker than normal gasket for the head as well that he gave me with it. I can only imagine what would happen if i had the gasket i bought =/

09RappySE
11-24-2013, 01:48 PM
If need be....you can also run a thicker or double base gasket to increase clearance.

tri again
11-24-2013, 01:55 PM
Play doh, play dough also works good for checking clearance, avail everywhere.
Good temperature range and looks pretty serious in one's tool box.

CodyRosa
11-24-2013, 02:07 PM
https://www.youtube.com/watch?v=d_iazohDl1Y


Thats what i'm dealing with. TDC when valves are both up.. as you can see in the video the piston is catching on something up top yet the valves are NOT moving AT all. I took the camshaft sprocket off and turned the motor over and no noises. I changed out the 200x cam with the 200m cam and still hitting valves or whatever its catching on. I'm pulling top end apart right now to check out if both valves are hitting now.

CodyRosa
11-24-2013, 02:21 PM
Now I got something for you all to rack your brain on... valves are not hitting the piston at all..

tri again
11-24-2013, 02:48 PM
Ridge reamer?
Any chance the rings are hanging up on a wear ridge in the cylinder?
I had a set of rings that were 'stepped', well the top one was, to eliminate that particular problem.
Broken ring or oil scraper.

so to review...all you really did was change the head and valves?
no bottom or piston changes?
does it stop at the same point when you walk it backwards AND fwd? or does it change?

09RappySE
11-24-2013, 03:19 PM
If it was a ring or ridge...you would know it if you rolled it over while the head was off....to me, it is either the piston hitting the head/head gasket or valves. since the sound goes away when you remove the cam sprocket...it sounds valve/valve train related. if it were me, I would clay it up and see what I actually have and go from there.

CodyRosa
11-24-2013, 06:38 PM
No I changed the piston, rings, and bored it. No ridge. So i took the top end off.. no damage anywhere.. I put my finger on the head gasket and kinda wiggled it, and decided just to throw it back together because it must not be anything at the piston... wellllllll it fixed itself.. It had to of been the head gasket. Idk what else it would have been. Still don't know why the intake valve hit the piston this time with piston 180 off. It didn't do it with the old head. Now I just need to get it running =D