piston in backwards for 2 years

[AJG400]

just got this wheeler from a buddy of mine who bought it around 2-3 years ago that had jus been bored to a 440. it ticked pretty loud and come to find out the cam chain was stretched so i changed the chain and tensioner and put it together and 4 of the valve cover bolts wouldnt tighten. the head gasket was starting to leak a little at one corner so i didnt really mind that i have to tear it back down to heli coil the head and cylinder. i just pulled the head today and find that the piston was put in backwards and the valves hav hit it a little. what i think is bs is our local honda dealership put a brand new head on it 2 yrs ago and should hav noticed this. so sorry for the book but im on a budget rite now so i was wondering if the piston is ok besides the little valve marks should i just turn it and i put back together with same rings etc with new gaskets? i kno i would b better off getting a new piston and rings and doing a hone but its outta my budget.

[Scro]

I'd say if it's ran for 2 years, you should be fine just installing it correctly. What I can't believe is how the valve was holding up for that long. You would think it would have bent a valve, atleast causing a little smoke.

But then again, I had a buddy put a piston in backwards in a 450r. It made it 1.5 hours of XC racing before dropping a valve, ruining the head, cylinder, and piston. I would say you are pretty lucky:p

[AJG400]

ya it doesnt really smoke at all granted my buddy didnt ride it much.

[jasonwayne222]

i had the same situation except the reason my valves contacted my piston was because i left out a cam bearing pin and the cam bearing walked off and caused the valves to open at the wrong time, your piston should be fine if its just little indentions on it from the valves, i used a dye grinder and smoothed them out, as for your valves just leak check them, i always poor fuel in the exhaust and intake ports and watch for a minute or two to see if u get any leakage around ur valves, if u do then pop out the valves and lapp them in until they dont leak, if their bent and leak real bad then just get new valves, i got some off of ebay for like 80 bucks shipped for all four, they are good quality and have held up great.

good luck

[jasonwayne222]

i had the same situation except the reason my valves contacted my piston was because i left out a cam bearing pin and the cam bearing walked off and caused the valves to open at the wrong time, your piston should be fine if its just little indentions on it from the valves, i used a dye grinder and smoothed them out, as for your valves just leak check them, i always poor fuel in the exhaust and intake ports and watch for a minute or two to see if u get any leakage around ur valves, if u do then pop out the valves and lapp them in until they dont leak, if their bent and leak real bad then just get new valves, i got some off of ebay for like 80 bucks shipped for all four, they are good quality and have held up great.

good luck

[AJG400]

im gonna say that the valves on the old head are the ones that hit and since it got a new head and valves the new ones didnt hit since the indentions were already ther. they dont seem to leak so i think im good to go.

[brokenmike]

I had the same problem, though my piston was not marked intake or exhaust. I put it in and started it, it made a louder than normal tap, I took the head off to find the intake valves had just touched the piston to barely mark it. I turned the piston around and it has been in there since 2002. No problems...

[rt20ps]

I recently pulled apart a Honda CRF450R to rebuild the head. I was surprised to find the piston in backwards. He had no problems with it. I guess he never revs the thing.....