Starter problem with 70 HP Johnson

hummer5

Cadet
Joined
Jul 8, 2006
Messages
7
I have a starter problem with a 1975 70 HP Johnson Seahorse. When I turn the ignition key to the start position, the starter will turn but the pinion gear ( if thats the right description?) will not rise to engage the flywheel and start the engine. If I keep the key in the start position, the starter starts revolving faster but the pinion still does not engage. A couple of times I raised the pinion gear with a screwdriver to engage the flywheel and then tried starting - nothing happened - no rotation, noise or anything else. The battery is nearly new and fully charged.

Earlier this year I had starting problems and after cleaning and polishing every visible ground connection and then spraying them with WD-40, the engine worked well. At that time I also sprayed a small amount of WD-40 on the worm gear of the starter. Everything worked well until a few days ago when I was winterizing it and when I tried to start it I encountered the starter problem described above.

Can someone provide me a diagnosis or solution to this problem? Thanks.
 

17bowrider

Cadet
Joined
Oct 7, 2010
Messages
11
Re: Starter problem with 70 HP Johnson

sounds like bad brushes but heard of it being dirty inside of them it gums up the brushes a little tap on the side dont help pull it apart have a look after you take it off i believe it only has 2 screws to pull a part but be carefull pulling very slowly incase its crushed inside they are springs?
 

Slojoe

Seaman Apprentice
Joined
Sep 13, 2009
Messages
32
Re: Starter problem with 70 HP Johnson

You can put 12 volts right to the starter at the cable lug, if it still doesn't turn then it's internal, probably just brushes as mentioned already. I replaced the brushes on my 72 with the same symptoms as yours, they cost 15 bucks at the auto electric shop.
 

hummer5

Cadet
Joined
Jul 8, 2006
Messages
7
Re: Starter problem with 70 HP Johnson

I did put 12 volts direct to the starter from the battery with booster cables and the symptoms were the same. So, in all likelihood I will take the advice of both posters and replace the brushes.
 

red_chaser

Seaman
Joined
Jan 26, 2010
Messages
62
Re: Starter problem with 70 HP Johnson

I did put 12 volts direct to the starter from the battery with booster cables and the symptoms were the same. So, in all likelihood I will take the advice of both posters and replace the brushes.

try ebay, i found mine there for less than $100 and some of them come with a one year warranty. i've had mine in for more than 8 months and it still works great, just bolt on and turn the key.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Starter problem with 70 HP Johnson

90% of starter problems are bad connections. remove and clean both ends of the battery cables, so that they are shiney, also the cable from the solenoid to starter. check for nicks in the cables. and make sure the connectors are on the wire good. the cable tend to corrode from the inside out, if nicked, corroded wires, and connections, heat up and cause resistance to the follow of electricity, thus the starter doesn't get enough. you can also take jumper cable pos battery post to large post on starter. with a good connection, the engine should spin. then if the starter is good clean everything and retest. then trouble shoot solenoid. starters can be rebuit at a starter/alternator shop, much cheaper than a new one.

Be sure the cables area connected to the correct battery post. crossing cables, usually blows the rectifier, and can blow more.

also have the battery load tested at the auto parts store, free, i've had new batteries go bad
 
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