89 50HP VRO RATTING SOUND

[ser742]

HELLO EVREY ONE my question is i have a 1989 50hp johnson vro theres a strange rattling sound that maybe is normal coming from the large flat cover located next to fuel filter sounds like rattiling marbels in your hand noticeable at all ranges of speed (increaes with speed /decreases as slowig down)no idle or any problems for that matter runs great threw out the hole powerband i do not have a manual as yet thats for my poor description its on the left side if you are looking at it from the back

 

[pine island fred]

Re: 89 50HP VRO RATTING SOUND

Hope its not the beginning of the same problem that happen to me. Remove the spark plugs, bring each piston close to top dead center by turning the flywheel by hand. Put some light pressure on the top of the piston with a screw driver and see if there is some play as you rotate thru TDC. Play will indicate impending wrist pin or rod bearing failure. It does not show up at first with power loss but goes downhill rapidally as failure continues. Good luck fred

 

[o/b tech]

Re: 89 50HP VRO RATTING SOUND

If the mechanical checks out as fred has stated, than what you might be hearing is detonation. Sometimes if a cylinder or cylinders run lean enough, it sounds like marbles rattling around in the motor.Every once in a while you come across a motor that you can hear the detonation above the noise of the motor. Check your timing and compare it to the decal on the air box cover. Try using a spray bottle with mixed gas in it and spry it into both carbs with the engine running. Be careful of moving parts.If the rattling dissapears than its time to clean the carbs.An engine can run at its best, due to a lean condition, before it blows. Hope its not mechanical and fixable.

 

[ser742]

Re: 89 50HP VRO RATTING SOUND

thanks pine island fred for your input checked the motor as you described there is definatley no play threw out bftdc or aftdc going to try the method described by o/b tech tommorow ...I wandered if it might not be the piston skirts being lose in bore i have a 97 jeep cherroke it sounds the same like on old disel it has 160,000 and it has that same rattle in it and holds 45lbs of oil pressure at 55 and 35lb at idle the boat motor has some where im told around 700 hours im told thanks for all your help let you know how it goes tommorrow

 

[G DANE]

Re: 89 50HP VRO RATTING SOUND

700 Hours is low hours, a lot does 3500 or more.

 

[ser742]

Re: 89 50HP VRO RATTING SOUND

WELL I TRIED the suggestion of o/b tech and went threw the carbs and cleaned them .. I must admit noise is there but not near as noticeable as it was before gonna just go out and enjoy it .THANKS TO EVERY ONE FOR THERE THOUGHTS AND TAKING TIME TO TELL ME >>>