50 HP Force starting problems

[fasterski]

Hi all. I was wondering if anyone can pinpoint where the issues might be.

The engine will not crank fast enough for it to start. I have brand new battery. When I remove the spark plugs it cranks over no problem. With the spark plugs in the starter barely cranks over and stops at compression point. I will try to attach a video. Maybe this will help.

Slow to crank over (plugs in)
https://1drv.ms/v/s!AiqvEVe5xKCr3h2cgiEfKh1EoIhN


Fast to crank over (plugs out)
https://1drv.ms/v/s!AiqvEVe5xKCr3h6Gx05kTRQqDFZ4

 

[jerryjerry05]

The first link showed the motor turning with no prob.
​The second showed a motor turning slow.

The first thing you do is do a compression test.
Low compression on 1 or more cyl.
​That's what it looks like to me.

​If your using the key to turn the motor over???
Then you need to ground the plug wires. You can blow the pack if the wires aren't grounded.
Or use a jump box.

Oh yea, Welcome to the site.

If you fill out the signature, put in the year, model and serial# for the motor.
​That way we never have to guess if you have another problem.

 

[fasterski]

Thanks Jerry,

i think i found the problem in this post.

http://www.marineengine.com/boat-fo...-force-hard-turning-over&highlight=hard+crank


basically another fella with exact same motor and symptoms found the crank broken in the half.

 

[blackd]

It is common to have the starter motor internals dirty and weak. Before you tear the motor apart, try cleaning the starter motor. Take it off the motor, and take it apart. Check the brushes to assure they are in fact making good contact, If not replace. If the brushes are OK, then clean the contacts. Put it back together and attach the battery cables to assure it spins off the motor. If so re-install on the motor and try again. If your problem continues then look at the more serious problems.

 

[kbh121956]

I would do as jerry jerry said. Do a compression check, if the crank is broken you will not have compression on number 2.

 

[kbh121956]

fasterski, pull the plugs and ground them. Turn the motor by hand with the flywheel (clockwise) and check to see if all pistons are moving. If they are, do a compression check. I wouldn't assume that the crank is broke just because some guys on youbube is doing the same thing.

 

[jerryjerry05]

IF?? you can turn the motor over???
Then I doubt seriously the crank is broken???