83 Merc 115 hard to turnover

[mikel2k]

Re: 83 Merc 115 hard to turnover

When you did your cranking voltage check
was your volt meter on the battery
or on the starter?

I tried both and it was well over 12v on each end.

 

[Big flop]

Re: 83 Merc 115 hard to turnover

Was that with the plugs in?
A motor straining that hard to crank
I would think you would see a lot
More of a voltage drop?

 

[mikel2k]

Re: 83 Merc 115 hard to turnover

Was that with the plugs in?
A motor straining that hard to crank
I would think you would see a lot
More of a voltage drop?

yes it does drops to 12.11 then to around 11.78 on the second pass when it strains. Its showing the same amps from the battery to the starter.

 

[aussieflash]

Re: 83 Merc 115 hard to turnover

After all the checks on starters,wiring etc have you checked the exhaust ports like the earlier post suggested.I'd also be looking at cylinder walls/piston ring condition.Battery can only do so much under duress.

 

[Big flop]

Re: 83 Merc 115 hard to turnover

When you did your cranking voltage test with
plugs in was the red lead on the starter power
Post and the black on the starter housing
Need to check cranking voltage right on the starter.

 

[dogyerf21]

Re: 83 Merc 115 hard to turnover

Any new insight on an old topic?? I have these symptoms to the "T" on a 73 merc 650 3cyl. When cranking, flywheel spins twice on third rev. starter bogs down and draws alot of power. Pull plugs and it turns like a bat out of gary,Indiana. Checked, checked, and re-checked and cleaned all starting connections. Held hand on connections after cranking to see if any were getting hot, nothing. Did compression test and all were equal. Tried to test timing, even though it should be correct ive used this motor for three years, but it wont crank fast enough to get a consistent timing "light". Is pulling the L.U. the only way to check for exhaust restrictions? Its not pulling it that bothers me,its the aligning and swearing to get it back on. Also, I dont know much about the reed valves. Do they only affect the intake side of things? My thought is that its an exhaust obstruction or something very bad internally? PLEASE help no hair left to pull!!

 

[Gomer50]

Re: 83 Merc 115 hard to turnover

I had purchased 3 motors that had problems very similar like yours,after testing starters checking wiring,etc I decided to do a compression test.I got some really odd results.Removed the transfer covers so I could get a good look at my pistons.Come to find out on my 80hp and my 85hp inline 4's the number 1 piston was fried,on my inline 6 it was the number 3 piston was toast.Tore them all apart installed new pistons and rings after a good honing slapped them back together and now my starters work like a charm and so do the motors.