how to check for bent valves

[BLOFLY]

is it possible to tell if valves are bent without pulling them out of the head, my heads off cams out the valves look like there seated well, ive looked for everything to get my bike running properly and this is the next thing to check in my process of elimination i will be pulling barrel of today sometime to check piston and rings, my bike started spluttering so i pulled all mods out of engine put stock stuff back in it ran no better so thats why i have the head off there was alot of carbon build up on inside of head no evidence of head gasket leaking i even bought a new carby spark plug and that didint fix it i dont know what else it could be there`s no knocking in the engine when it was running but it was running real bad, any ideas anybody PLEASE

 

[sixeven]

fill the ports with fuel or kero and see if it leaks around the valves. if it does then pull out the valves and get them checked

 

[daniel40]

or if uve got a dint on ur piston that could be the valves

 

[kart_ss]

fill the ports with fuel or kero and see if it leaks around the valves. if it does then pull out the valves and get them checked

Or just hand lap the valves.

Get suction cup on a stick, some lapping compound, and twirl away

 

[scribbles]

wat u meen running bad? like makeing weird noises and where?

 

[BLOFLY]

it was`nt making any bad noises it just wont rev out if i try and give it a handful it splutters and nearly dies

 

[BLOFLY]

fill the ports with fuel or kero and see if it leaks around the valves. if it does then pull out the valves and get them checked

thanks sixeven i filled the ports with fuel and was even able to put a lilltle bit of pressure behind it and no leaks so its not a bent valve, i also pulled barrel off and there is no evidence of wear the original hone marks are still visible in bore this motor does`nt even look like its run in fully so i`l order new head gaskets today put it all back together and try again, the barrel gasket does look like it got some dirt behind it i dont know how all head bolts were tight, now ive checked everything possible hopefully with a new set of gaskets it will be ok but i doubt it. any ideas anyone

 

[Power Man]

no valve problem mate, spluttering if the inability to ignite the fuel.

this could be caused by

- ignition timing , this could be out causing it to not run at is full potential , usualy pretty easy to diagnose if thats the case.

- your carby may have a blockage in it , and or your air filter may be restricting your motor , either its too small or blocked.

- your muffler also may be obstructing the flow of exhaust and "choking" when you give it some juice.

if it is infact a bent valve , you will have little to zero compression as the air will leak around that valve and not be compressed.

check the status of your carby , your muffler and possibly your timing before you take the head off.

 

[BLOFLY]

thanks power man i went to the extent of buying a new carby tried all timming settings possible even fully replaced all electrics spark plug so pulling the head off was the last option i had i will be putting it all back together as soon as i get a new head gasket and re do valve clearences. it had a good carbon build up inside the motor