mercury motor- very sick- needs a doctor

[QUOTE=Embrey;393603]probly not much of a way other than pulling the plug wires. did you try that? and the prop doesnt sound right. id take it off and see whats up there. does it make the sound in neutral, in gear or both? if it does it in neutral also, is say the prop and lower unit isnt the problem, cause it shouldnt be spinning in neutral[/QUOTE]

no i haven't tried, pulling the wires yet. even if i pull the plug wires, don't the piston keep moving up and down. or does pulling the wire and stopping the plug from firing stop it from moving.

lol...no. it wont make the piston stop moving...but it will kill the spark. which in turn will take the firing load off the crank from the rod and piston,which will sometimes make the noise fainter or go away completely. the motor will run rough when you do it, but pay attention to the area the noise is coming from when you pull one.if no change, put it back on,and try the next one until you find it. this doesnt always work,especially if its too far gone already. but if it does, its a cheap quick way to make a decision on whats up with it. oh, and dont get shocked...:)

[QUOTE=Embrey;393609]lol...no. it wont make the piston stop moving...but it will kill the spark. which in turn will take the firing load off the crank from the rod and piston,which will sometimes make the noise fainter or go away completely. the motor will run rough when you do it, but pay attention to the area the noise is coming from when you pull one.if no change, put it back on,and try the next one until you find it. this doesnt always work,especially if its too far gone already. but if it does, its a cheap quick way to make a decision on whats up with it. oh, and dont get shocked...:)[/QUOTE]

thanks, for the response. i will try that. the reason i think it's the motor, is the noise started after it shut off on the lake the other day. but i googled the movement of the prop shaft, and it said. it wasn't normal to have the movement. so it could be something gone wrong their. i would prefer that instead of a burnt rod bearing. any way i have to find the problem and fix it. i'm afraid to get very far from the boat ramp, the way it sounds.

well find out sooner than later. if it is a rod it wont let you know when its gonna come out the side of the block

If the shaft move in and out about an inch, then you've got a lower unit issue. If the shaft will also go up and down then it's probably a bearing issue. If the shaft just goes in and out most likely a snap ring issue. If you're handy with tools then it's not a bad do it yourself job.

[url]http://www.crowleymarine.com/mercury_parts/11211/240.cfm[/url]

you ever figure out whats up with the motor?

[QUOTE=Embrey;394292]you ever figure out whats up with the motor?[/QUOTE]

yes, it had a piston rubbing the cylinder wall.from not getting enough oil. and making the knocking sound. I tore it apart, ordered myself a repair manual. and a rebuilding kit. rebuilt it myself, and it runs great. and with the repair manual, it showed me how to check the fuel enricher, and it wasn't getting any fire. ran a new wire from keyswitch to enricher, now it works. no more problem with cold starting. so far it's working great. ps... I plugged the self oiler off, and I'm mixing the oil in the gas tank myself. so if the cylinders get gas, they get oil. I'll never trust the auto oiler again.:):)

It sounds like a lower unit problem to me. If your prop is moving in and out up to an inch you have an issue down there. If your not hearing it under load it's likely because of the pressure against the prop holding it back on the prop shaft while your moving.
Does the prop shaft move or just the prop on the shaft?
Either way I think that I would drain the lower unit and take a look at the fluids. If you have a worn lower unit because of improper prop installation or something else internally you could be hearing a "referred" noise.
Has the lower unit been rebuilt? Water pump recently replaced?
This could be a drive shaft that is improperly shimmed or aligned causing a small vibration with a more resounding noise up top.
I would be looking for metal in the lower unit fluids and make sure there is no water due to improper bearing carrier installation, seal failure due to excessive movement etc.
Hope you find the cause.... Hope this helps