mercury motor- very sick- needs a doctor

[steemer1]

Check the compression I blew a rod completely through the top of my 200 Johnson venom. Now I have a new 225 Etec Evinrude on the back of my 201 Stratos.

[Embrey]

Check the compression I blew a rod completely through the top of my 200 Johnson venom. Now I have a new 225 Etec Evinrude on the back of my 201 Stratos.

well a rod probly wont show any different on a compression test sadly. but if he was starving it for gas, it could have definately hurt a rod ,being a 2 stroke. if it makes that noise at idle, you could pull one plug wire at a time and see if it goes away on a certain cylinder. might lead to figuring out whats up

[waterdog101]

well a rod probly wont show any different on a compression test sadly. but if he was starving it for gas, it could have definately hurt a rod ,being a 2 stroke. if it makes that noise at idle, you could pull one plug wire at a time and see if it goes away on a certain cylinder. might lead to figuring out whats up

I've been busy today, but i did go get a compression gauge. it was dark out so i didn't warm the motor up before i checked the pressure. i'll have to do it over. but the cold check was 130 psi on all 3 cylinders. and i thank you for the reply. what you said about the noise at idle, and pulling a plug wire. made me think of something. when at full throttle the noise went away, or i just could not hear it. so if it is a rod barren making the noise while at an idle or low throttle. when at full throttle it would have enough pressure on it to take the noise away. does this make sense?

[Embrey]

could be...rods usually make the most noise at idle or after revving on the way back down. not always, but usually

[waterdog101]

could be...rods usually make the most noise at idle or after revving on the way back down. not always, but usually

thanks, for the reply. that could be it. I will try pulling the plug wires one at a time. to find the one it is. it just don't make sense, almost a new motor. and it's gone bad. and the last motor i had was a rebuilt 20 year old johnson, and i ran it 7 years trouble free.

[dausefarms]

Is the motor fuel injected? If it is possible injector.

[Embrey]

true...but if its that, he would notice major performance loss i would think

[waterdog101]

true...but if its that, he would notice major performance loss i would think

I went to the lake today, this motor has plenty power. i laid down and put my head back close to the motor. while it was idling. the sound, sounded like it was in the area at the bottom of the motor, and at the top of the shaft. how can i tell if it has a problem with a rod or bearing. with out tearing the motor apart. and standing behind the motor, the prop can be pushed in about a inch. is this normal for the prop to have enough play to push in and pull out about an inch.

[Embrey]

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

[waterdog101]

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

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.

[Embrey]

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...

[waterdog101]

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...

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.