Clicking sound only under payload

[Shawn79]

hi I recently purchased a 1987 canaventure with a rebuilt 3.0 litre merc the previous owner had disconected the choke for some reason that i am unsure of butt recently i here a tapping sound that seams to be coming from the carb its not the choke plate i cheked that butt this only happens when the boat is under payload(in the water with weight) it doesn;t realy affect the power to much just a litle rough off the start. does anyone have a clue i am stumped

 

[Trent]

Re: Clicking sound only under payload

see other post

 

[DemersChrisG]

Re: Clicking sound only under payload

Yep, its either one of two things. (1) You have an exaust leak. Exaust leaks make a tapping noise, the more load placed on it, the louder it gets. (2) If you say its comming from the Carb, your rocker arms might need to be re-tightened/re-tourqued.<br />Also, valve lifters are known to tap when they get up thre in age, but if the engine have been rebuilt, they should be just fine.

 

[Shawn79]

Re: Clicking sound only under payload

yeh the engine was rebuilt around 18 months ago butt if it was valve lifters or rocker arms wouldn;t they make a noise at all times not just under load???? i am going to chek the exhaust i think that may be it

 

[DemersChrisG]

Re: Clicking sound only under payload

No, Back when I first rebuilt my 350 Everything was fine at low RPM, then once throttle increased and load increased the engine started sputtering and a click noise came from what seemed to be the carb. <br />First things first though, make sure your exaust manifold is tight, and the gasket it in good shape. Loud ticking under load is probably exaust replated.

 

[DemersChrisG]

Re: Clicking sound only under payload

I cant spell, replated = related

 

[Don S]

Re: Clicking sound only under payload

Overfilling the crankcase can cause the crankshaft to hit the oil and areate it. This will cause the lifters to get soft and cause a tapping.<br />I have also had lifter noises start when the oil was changed to synthetic. Changing back to regular oil cured the problem.

 

[Shawn79]

Re: Clicking sound only under payload

would low oil and when i say low i mean maybe 3 quarters of a quart low cause this noise, i inspected the manifold noticed a lil rust on the elbow how can i do a real good inspection on the exhaust any info would help thanks

 

[jeff13601]

Re: Clicking sound only under payload

Are you saying that you are 3 quarts low? Three quarts will make more then your lifters tap. I believe it only holds five

 

[Shawn79]

Re: Clicking sound only under payload

no not 3 quarts about a quart tops!!!!