89 80hp merc clicking sound

[delsol]

i just put a new water pump in my engine, thought that my oil injector might not have been working properly. but ran boat . it would shut off at high speed. i would pump ball and it would restart. get up to top speed and stall again. i started to think fuel pump as it started to stall alot , or bad gas. so i felt ok till i was almost back to the dock now motor is tapping like a piston slap. could this be a piston failure. if the piston or rod was bad would i still have good compression..i am sick over this because last week it was steady buzzing sound in shifter, so i replaced themostat, and water pump and the buzzing when away . what would be good to check out.
bob

 

[sport15]

Re: 89 80hp merc clicking sound

Did the level in the oil tank drop at all? Pull the plugs and check for metal on the plugs and inside cylinders. You could shoot marvel mystry oil in the jugs, put a wooden dowel in through the plug hole and gently turn over by hand to see it all the piston heads are still intact. Better yet, pull the head and check the walls for scoring. The damage is already done if you broke a piston or rings so be really careful about making it worse. Good Luck!!

 

[delsol]

Re: 89 80hp merc clicking sound

oil tank level droped a little, i only used 6 -8 gal of fuel.but it did not smoke like it usally does while running when starting it did smoke like normal.. can pison be replaced on motor or does powerhead have to come off???the clicking was very noticeable to me. at first no clicking just stalling from high speed..

 

[delsol]

Re: 89 80hp merc clicking sound

also its a shame this motor is really clean fresh water motor 1988-89 insides look like 99-01 motor very clean..i should have done a premix and not used the oil injection. i know i am putting the wagon ahead of the horse but. i think i am in trouble here..any other advice to check things

 

[jze1212]

Re: 89 80hp merc clicking sound

So it does not knock until the motor is warmed up? I would pull the head and have alook in there for scoring, like Sport15 said....

I have an 89 100hp , and I think the the previous owner overheated it and it has a tiny tap coming from the number 1 cylinder, right after you start it the noise goes away, I was told that It may be piston skirt...

If noise dont go away after running to temperature you should stop using it and tear into it! Good luck

 

[delsol]

Re: 89 80hp merc clicking sound

can a piston be replaced on the motor or is it impossible???i rebuilt an 135hp johnson 2 yrs ago..no no more 2 heavy and i am 2 old for that living in the city and no garage
bob/philly pa

 

[delsol]

Re: 89 80hp merc clicking sound

could the tapping be other then piston
bob

 

[delsol]

Re: 89 80hp merc clicking sound

anyone

 

[MortenH]

Re: 89 80hp merc clicking sound

Do a compression test. If no compression, your rings might be gone. If some then it might be the piston. I have experienced both - a melted piston made a terrible sound, gone rings just a tapping sound. But I guess you will have to open her up to see. When my piston rings broke, the cylinder was not damaged, and I just had to replace the piston with rings. I am no expert, but I dont think that the tapping can be other than piston / rings related. I am not quite sure about your engine, but I guess the power head have to come off to do a piston replacement.

-M-

 

[delsol]

Re: 89 80hp merc clicking sound found problem

Re: 89 80hp merc clicking sound found problem

found bad compression 90 2 cly. 25 other cly. took off power head. deciding this late in season to fix myself or get power head rebuilt. found a place on internet $1500 but thats all boat motor trailer are worth ..might shoot for a new boat over the winter. we only have about 6 -8 good weekend left here in pa.
bob

 

[Texasmark]

Re: 89 80hp merc clicking sound

Does the 89 80 hp (4 cyl I assume) have a cylinder head? My 89 115 (6 cyl) didn't; had a water jacket cover, but no cylinder head....head was cast as an integral part of the block the way they built Merc's years ago.

You said that you ran out of fuel and the engine died at high rpm's. With that after your temp problems, you could have damaged a piston.

Another place to look for debris is to take the exhaust water jacket covers off and look directly at/in the exhaust ports. If you have any metal embedded in the piston, or a damaged cylinder wall you will have a good opportunity to see it.

Mark

 

[delsol]

Re: 89 80hp merc clicking sound

thanks mark 3 cyl
i will take off water jacket today