50 hp does turn over right

[gdp]

My 2nd boat has a 2005 50hp Johnson. At times the starter doesn't spin the moter enough rpm to start. It acts like the battery is low. Other times it turns over like it is suppose to. Checked the battery it showed around 12.5 volts also put a load on it and it showed good. Tried another battery and it did the same thing sometimes it turns over fine and other times it drags and will not hardly turn the motor over. Local dealer installed new brushes in the starter and still does the same thing. I put a meter on the starter when it was turning over and it showed around 10 volts at the starter. Is this correct or should it show close to 12 volts? This motor probably has not had 50 gallons of gas run through it low hours. It started doing this the first thing this spring. Also checked all the grounds I could find. Any ideas? Thanks

[flabum1017]

99% of the time that problem is due to loose battery connections or a bad battery,

Have someone load test and Hydrometer test the battery,

Next, remove the battery cables at the battery and clean the contacts..... put the cables back on TIGHT, not finger tigth with the wingnuts, but wrench tight with real SS lock nuts.. Next, do the same at the engine end. Check the entire length of the battery cables for bulges...... bulges usually indicate internal corrosion.

10 volts while cranking is good.

[gdp]

Flabum thanks for the reply. I have had the battery load checked and even tried a different battery from my V6. I have also already cleaned and made sure all the connections are clean and tight on both ends of the battery cable. I have not followed the cables back. Any other ideas? Thanks gdp

[Bruster]

Check the cables. I have seen twice this summer on pontoon boats (both were OMC/BRP battery cables) where the cables were corroded in the middle of the cable. When I cut the cable apart it was all corrosion and only a few strands of the cable were still intact.


Flabum thanks for the reply. I have had the battery load checked and even tried a different battery from my V6. I have also already cleaned and made sure all the connections are clean and tight on both ends of the battery cable. I have not followed the cables back. Any other ideas? Thanks gdp

[jacklake2003]

Maybe the relay?

[stvgar]

All great advice above, after everything else is ruled out, sounds like the brushes in the starter. Used to be able to replace those in the older motors.

[Bruster]

Beat ya to that.


My 2nd boat has a 2005 50hp Johnson. At times the starter doesn't spin the moter enough rpm to start. It acts like the battery is low. Other times it turns over like it is suppose to. Checked the battery it showed around 12.5 volts also put a load on it and it showed good. Tried another battery and it did the same thing sometimes it turns over fine and other times it drags and will not hardly turn the motor over. Local dealer installed new brushes in the starter and still does the same thing. I put a meter on the starter when it was turning over and it showed around 10 volts at the starter. Is this correct or should it show close to 12 volts? This motor probably has not had 50 gallons of gas run through it low hours. It started doing this the first thing this spring. Also checked all the grounds I could find. Any ideas? Thanks


All great advice above, after everything else is ruled out, sounds like the brushes in the starter. Used to be able to replace those in the older motors.

[M. HARDEE]

IF CABLES ARE GOOD , starter has been used with low voltage (bad or week battery, loose connections , etc )will heat up armature, if armature has been too hot new brushes will not fix . REPLACE STARTER OR ARMATURE

[gdp]

None of the suggestions seem to help. I have noticed when the motor turns over slow the battery shows around 12.3 volts on a tester and when it turns over normal it says 12.5 or a little more. .2 of a volt shouldn't make any difference should it? 12.3 volts should turn the motor over ok shouldn't it? I have had the battery load tested and even tried a different battery plus checked all the grounds and had new brushes put in the starter. Any ideas??? Thanks

[Bruster]

I have a starter and solenoid for your motor that worked fine right up to the day #2 cooked. $50 + $10 ship in US.


None of the suggestions seem to help. I have noticed when the motor turns over slow the battery shows around 12.3 volts on a tester and when it turns over normal it says 12.5 or a little more. .2 of a volt shouldn't make any difference should it? 12.3 volts should turn the motor over ok shouldn't it? I have had the battery load tested and even tried a different battery plus checked all the grounds and had new brushes put in the starter. Any ideas??? Thanks