Is it the starter motor??

[kellaig]

Hi there,

i have a 2003 60 Hp 4 stroke carburettor outboard. Intermittently say about 10 times a day the starter motor fails to engage the fly wheel and won't turn the motor . Is it the Bendix spring sticking occasionaly or not aligned properly.

If i turn the key again it will crank over the motor and it starts.

Is this a safety mechanism or what else could be causing this outboard to behave this way.


Regards

Craig

[Ken]

Craig,
The most common cause of the starter pinion gear not engaging the flywheel is the starter motor not spinning fast enough so that the inertia (weight) of the pinion does not make the pinion ride up all the way to the flywheel.
The starter motor not spinning fast enough is caused by either a weak battery or poor connections between the battery and the starter,
or a bad winding in the starter motor.
You need to remove the hood and observe the action of the pinion gear when someone hits the starter switch. Be sure and pull the ignition kill switch lanyard - you don't wont the motor starting up while you're doing this. You will probably have to remove a protective cover over the flywheel. Be careful working around the starter and flywheel (they will chew up your finger if you get one close enough). If the pinion gear does not travel all the way up the starter shaft to the pinion stop, then either a weak battery or poor connections. You can jumper directly from a fully charged battery to the starter and eliminate any possible bad connections and observe pinion action to see if that makes any difference.
Or your problem could be a bad pinion spring (maybe broken) and causing the pinion gear to hang up on the shaft. You would need to remove the starter and disassemble the pinion stop, spring, and gear and inspect.
If the pinion gear is traveling up to the flywheel and actually slams into it but does not mesh (engage) with the flywheel teeth, then you have a different problem. Could be a loose starter - check the mounting bolts. Could be bad or broken teeth on either the pinion or the flywheel. Inspect all teeth on both.
Has the starter been working ok up until now, or has it always done this?
Ken K [img]smile.gif[/img]

[kellaig]

Hi Ken,
Thanks for the reply.
This motor has done this since new. It has only done 70 hrs. As it only does it now and again,they have trouble finding the fault at the shop. It now does it about 20% of times i begin to start it. After it fails, i try again immediately and it always starts.

They have checked the pinion gear and checked all connections and batteries. It may be time to get them to pull the starter motor off.

Regards

Kellaig

[kellaig]

Ken and others,

I took out emergency kill switch and checked operation. When it worked fine, gear would come up and continue to turn engine fly wheel. Every third or fourth time i did this the gear would go up and turn the flywheel for a brief second and then fall down and continue to free spin below fly wheel. This is what happens on the water.

Any more suggestions???

Regards

Kellaig

[Ken]

Kellaig,
I was afraid you were going to say the starter has done this from the git-go. So, now, I will share my personal experience with you.
Back in 2000 I bought a Pathfinder with a C115 Yamaha. The salesman takes me for a "checkout" ride in my new boat. The first time he hits the starter, I hear this "wheeeeeeee". He trys it again, and the starter engages the flywheel and the motor starts. No big deal, I thought - probably just a sticky relay. Long story short, I did not do anything during the warranty period of two years, thinking I would take the motor to my trusted marine mechanic (he was not a Yamaha dealer unfortunately). After the warranty, the starter malfunction got worse, of course, so that about every third hit on the starter, the pinion gear would come up and slam against the bottom of the flywheel but would not engage. You could see that the teeth on both the pinion gear and the flywheel were beating the crap out of each other.
I talked to several Yamaha dealers in the area, and my trusted marine mechanic. I also tried to get in touch with the factory, but got no response there. I posted my problem on several forums, including this one. All that anyone could tell me was to replace the starter and/or flywheel to see if that would fix the problem - sure, to the tune of over one kilobuck, and even then, no guarantees.
So, I did my own investigation and began to examine starter pinion gears and flywheels on other Yamaha 115s of approx the same vintage. And, viola, here's what I found:
Either the pinion gear or the flywheel teeth have got to be beveled. My neighbors 98 C115 flywheel has the bottom of the teeth beveled. I examined my Yamaha shop manual and it showed that the pinion gear on the 2000 starter was beveled. I checked my starter pinion - no bevel. I checked my flywheel - no bevel. Both sets of gear teeth cut at 90 degrees.
Also, after removing the starter and pulling the pinion gear, I discovered that the spacers that the shop manual showed were missing. These spacers reduce the "resting" gap between the top of the pinion and the bottom of the flywheel. I added a spacer (hand made, thank you very much, 'cause Yamaha wanted $42 for one) and reduced the gap from 150 thousands (inch) to approx .085.
So, I got out the old Dremel tool and decided I would attempt to reshape the badly disfigured teeth on both the pinion and the flywheel. I really had nothing to lose at this point. So, armed with a special metal grinding wheel and a Dremel drill stand, I reshaped the pinion and cut the top of the teeth at 45 degrees - just guessing as to how much bevel was needed. I did not want to pull the flywheel, so I "free-handed" the grinding on the teeth of the flywheel, trying to reshape the beaten rounded bottoms where the pinion had been slamming into them - trying to put a right angle cut on them.
Well, that was at the beginning of last spring, and I have gone on many fishing trips since then, and I am still crossing my fingers - the starter has yet to fail me.
I don't know if doing the bevel trick or adding the spacer fixed my problem. Probably a little of both.
Bottom line to you, have the shop take a look at the beveling - I think it should be on the pinion gear. Also, have them check for the spacer under the pinion gear. I hope you are still under warranty.
Good luck [img]smile.gif[/img] ,
Ken K