new top end...need help after install

[400thacker]

I just put a new stock top end on my 250X
I used a fresh 300ex cylinder and used but in good condition 250x piston with new Honda rings. BTW i had everything clearanced and the compression is great.

first issue is NOISE coming from the rocker cover. sounds like really loose valve lash but I finger tightened the adjusters all the way then torqued the keepers and it's still making noise. Seems like it is on the up and down stroke of the front and back valves. 2 loud clicks per revolution. I have no idea what it is or what to look for other than valve lash or severly worn rockers but I don't have worn rockers and the valve lash is kind of tight in my opinion. The rockers only have side to side play, no play at all up and down. The cam is also used but in very good shape.


problem #2 is I have some white smoke. It's not terrible but it's enough that I am concerned. Not alot more smoke when I rev it either.
I used Lucas oil stabilizer to lube the cylinder when I installed the piston so I thought that might be the problem or when i bought the rings before i got the new cylinder, the oil wiper ring was REALLY tight so honda told me to cut it just a little to make it fit better. That helped and made the piston fit much better. The piston was still tight in the new cylinder but I don't know if that could have anything to do with it or not. could I try the old oil wider ring. ( ring that looks like a spring thing)

Thanks in advance guys.

[smr]

Originally posted by 400thacker
I just put a new stock top end on my 250X
I used a fresh 300ex cylinder and used but in good condition 250x piston with new Honda rings. BTW i had everything clearanced and the compression is great.

first issue is NOISE coming from the rocker cover. sounds like really loose valve lash but I finger tightened the adjusters all the way then torqued the keepers and it's still making noise. Seems like it is on the up and down stroke of the front and back valves. 2 loud clicks per revolution. I have no idea what it is or what to look for other than valve lash or severly worn rockers but I don't have worn rockers and the valve lash is kind of tight in my opinion. The rockers only have side to side play, no play at all up and down. The cam is also used but in very good shape.


problem #2 is I have some white smoke. It's not terrible but it's enough that I am concerned. Not alot more smoke when I rev it either.
I used Lucas oil stabilizer to lube the cylinder when I installed the piston so I thought that might be the problem or when i bought the rings before i got the new cylinder, the oil wiper ring was REALLY tight so honda told me to cut it just a little to make it fit better. That helped and made the piston fit much better. The piston was still tight in the new cylinder but I don't know if that could have anything to do with it or not. could I try the old oil wider ring. ( ring that looks like a spring thing)

Thanks in advance guys.

don't understand why you would have to cut the wiper. I've never done that.

White smoke after a rebuild is not uncommon. Usually it will go away after the rings set.

As for you noise. How was the timing chain. If you and lift it up and down at all then it's to loose.

let us know what you find.

[400thacker]

there isn't any play in the timing chain but the tentioner is all the way out I believe.

[400thacker]

how long should it take for the rings to seat?

[smr]

depending on the hone job you or the shop did after the bore. It should stop after the first good day of riding.

Now..I have learned, if you used a wisco piston I have had them to smoke a little and never stop.

recheck your valves. They should be no more the .004. I set the intake and exhaust at .004. I have seen people set them 180 degres off. The quad shouldn't run if you do that and they will be really loose when you get the lobs down again.

If the vavles are good I would say the noise is the timing chain.

[400thacker]

yeah the valves are good, I didn't use a base gasket on the cylinder do you think that the valves could be touching the piston a little bit?

I think it's the timing chain. I will replace that first.

[400thacker]

figured it out guys! thanks for the imput.

I left the bolts on the cam gear finger tight and the vibration of the motor started woth them out so the cam gear was loose and making all the noise. lol lesson learned i guess.

It does need a new timing chain.

thanks again