95 evinrude 200 knocking

7894steve

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Jun 5, 2009
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23
i am new to this forum game but not new to motors. i have a problem with a 200 ocean pro evionrude i just got.i will make this quick and if i get feedback i will go futher. my problem is i have used this boat about 8-10 hrs so far and it is starting to develop a knocking noise. i am familiar with several types of motor including 2 strokes. when it started it sounded to me as if a large piece of carbon got stuck on top of a piston and was hitting the head.it is very hard to tell exactly where the noise is coming from but it sounded like one of the top cyl, on the head side. i pulled the heads and found what i thought was a clean spot where the contact was. i cleaned it, checked the cyls and put it back. the noise is still there. this noise is pretty loud even a untrained ear can here it. second guess is piston skirt slap but i would like some opinions before i take the motor apart. it has been running about 3 hrs with this noise at about 4400 rpms. it is not getting any louder but it is not getting any better. i think if it were a rod knock it wouldnt have made it this long. i will take the lower unit off and run it to eliminate it later this week. can anyone offer any suggestions or knowledge about the particulars of this motor. anything will help before i strip it down. thanks steve
 

poorboy123

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Jun 5, 2009
Messages
8
Re: 95 evinrude 200 knocking

can you here the knock under acceleration or when the engine levels out?
 

7894steve

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Jun 5, 2009
Messages
23
Re: 95 evinrude 200 knocking

can you here the knock under acceleration or when the engine levels out?
you can still hear it under acceleration but about 2000 it seems quieter but i think that is because the rest of the engine gets louder. it is most noticable from idle to about 1700.i have seen the video someone else sent me and i do have a loose piston with lower comp but it is not nearly as bad as the video. also i did a comp check as soon as i got it and that cyl was low when i got it but it was quiet as a church mouse (thats why i bought the motor). this noise seemed to just happen when i was coming home from fishing after about a 1.5 hr run. have any ideas what to look at next. i am going to look at the vro pump today but i doubt it could be making this much noise. any info may help. thanks steve
 

7894steve

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Jun 5, 2009
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jonesg

Admiral
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Feb 22, 2008
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7,198
Re: 95 evinrude 200 knocking

Remove the sparkplug from the low compression hole, insert a dowel and follow the piston over TDC with very little (none) pressure on the dowel, now press down on the dowel and see if theres any play in the rod, could be either end of the rod if there is.

if the rods are good then it might be a stuck ring, you could try a seafoam treatment to loosen it up.
 

Benny1963

Lieutenant
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Sep 17, 2006
Messages
1,476
Re: 95 evinrude 200 knocking

probaly wrist pin bearing or piston skirt collapse .has it benn overheated
 

7894steve

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Joined
Jun 5, 2009
Messages
23
Re: 95 evinrude 200 knocking

i pullled the heads again and found the cyl is totaly scored up, it must have leaned out some more. the piston is realy loose now and that is my niose. anyway thanks for the help, i found a new motor for the boat.maybe ill rebuild this one to. thanks steve
 
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