hey im new to this so can someone help me out. well i put a new piston in my 250x and put i back together and it runs very rich. it ran rich before i put it in but after i put the piston it u can start it up run it for a few min and and the spark plug is fouled. when i took the valve cover off i noticed that the rocker arm was real loose what can that be from? do i need a new cam or cam chain? it runs fine tho, starts right up and runs very strong. need help

 

have you adjusted the valves?

 

yea every time i take the valve cover off i check it unless im doin it wrong

 

 

You say every time you've had the valve cover off you check it, has it needed adjusting or has it been ok? I ask because years ago I had a similar problem and the clearance was off every time I checked--first was every few months then monthly then weekly and I had to do a PROPER valve job to fix the problem correctly, the valve was hammering itself down into the seat(head) so when checked it was off every time.Not saying this is your problem but just a possible.

 

yea it was off every time i would adjust it every time. how would you fix that problem? new valves and springs or what? thanks for all the help

 

If it ran better after you adjusted them and then it gets worse till adjusted again I'd say valve job, cost would depend on how bad the valve seat is hammered there are so many variables, worse case you need a new head. "Normally" when doing a valve job for machine shop work you have the valve, and valve seat cut and the valve guide knurled or replaced--For parts it depends on if the valve can be cut & saved and you have check the condition of the valve spring.Of course you can short cut it, you wouldn't be the first so if you have the ability and tools to replace a piston to completion then with a bit of machine shop work to your head you can easily do the job. I'd take the head off bring it to a machine shop or whoever you know for this stuff and have them tell you how bad it is. The valves for that motor are inexpensive, most of your worries are the heads condition and even then there is always ebay for a whole used head which is a easy find. Post how you make out with it.

 

If the adjustment keeps changing then the head will have to be removed and the valves checked .. If the valve head is beating into the seat the valve will usually tighten on you .. If the valve stem starts mushrooming then the valve will usually keep getting loose .. The valve seat can be re-cut as long as it's not beat to much, the valve can't be re-ground on a Honda you have to replace it .. Either way the head should be taken to an engine shop ..

Here's a picture of a set of valves that were beat into the seat on a CRF250R

 

I was looking on ebay and seen complete refurbished heads ready to just bolt on and they were 129. that was with the head bead blasted and painted, seats cut,new valve stem seals,new valves,valves lapped, head pressure tested -oh heck here just go to this link---- http://stores.ebay.com/G-H-Discount-Atv-Supply

 

That is a dal on the plastic on ebay