Mercury 250efi STRANGE NOISE????????

[rsass]

I need some advice, i just rebuild my 2001 mercury 250efi and i'm starting to hear a strange noise(like reving out or metal sound) when i add more trottle around 2000rpm and then i'l just pull it back. do you think its with the engine cause someone was telling me it could be the gears in the lowerunit(foot) or the prop. please advice.thank you.

 

[Faztbullet]

Re: Mercury 250efi STRANGE NOISE????????

What caused your original failure? Did you repair the problem? What did you exactly replace? Did you replace upper/lower bearing? Does it do it out of gear or only in gear?

 

[rsass]

Re: Mercury 250efi STRANGE NOISE????????

the original failure was that the engine was loosing power and the compression was very low so we had it rebuilt with new pistons and seals etc,now the compression is good. but the engine did not have that problem before.these mechanics here really sucks and to tell you the truth i'm worst,im fed up off them trying thats why i joined the forum to get advice and try deal with it myself. So what im gonna do today is put a drum of water under the unit and start it and rev it to see what is really happening and i'll report to you with better info. Thanks.

 

[rsass]

Re: Mercury 250efi STRANGE NOISE????????

it only does it in gear, the engine sounds real smooth it idels real nice and if we leave it around 2000rpm it works fine but as we give more trottle it makes that noise.

 

[Faztbullet]

Re: Mercury 250efi STRANGE NOISE????????

Check the following:
1) Correct spark plugs..piston could hit them if incorrect type/lenght
2) Flywheel is torqued correctly
3) Loose stator under flywheel
4) Improperly mounted alternator(loose)
5) Gearcase problem(kind of doubt it)
6) Upper bearing problem
7) Connecting rod improperly torqued
8) Loose or broken plastic hub in prop(if plastic hub style prop)

 

[sschefer]

Re: Mercury 250efi STRANGE NOISE????????

Just curious, is it a grinding sound or a clanking sound?

 

[rsass]

Re: Mercury 250efi STRANGE NOISE????????

Check the following:
1) Correct spark plugs..piston could hit them if incorrect type/lenght
2) Flywheel is torqued correctly
3) Loose stator under flywheel
4) Improperly mounted alternator(loose)
5) Gearcase problem(kind of doubt it)
6) Upper bearing problem
7) Connecting rod improperly torqued
8) Loose or broken plastic hub in prop(if plastic hub style prop)

hey it seems the problem might be the stator under the flywheel, the mechanic said its only firing 3 cylinders. so i ordered a new one and then i'l try it and let you know. Thanks for the help buddy.i'l keep you posted.

 

[rsass]

Re: Mercury 250efi STRANGE NOISE????????

Just curious, is it a grinding sound or a clanking sound?

to tell you the truth its kindoff a confusing sound a little mixture off both. i only heard it 1 time.