# 2006 Yamaha F40 Starter Problem



## ek02 (May 8, 2012)

We have 2 Yamaha F40's that the starter hesitates when first cranked. On one 40 I was able to disassemble the starter and clean the brushes and commutator, lube the bushings with light turbine oil, and it starts fine now. I did the same to the other engines starter, but it still hesitates on the first crank, then spins fast until it starts. Fresh hot battery, new cables, new start relay. Anyone had this problem before?


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## ET101 (Sep 10, 2020)

I had this problem on mine and ended up replacing the starter. But mine was under for 2 days and sat for 6 months prior to me purchasing it. I will try to post a picture of how bad mine was.


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## ek02 (May 8, 2012)

Thanks. That does look pretty bad. Both of our starters have no corrosion. I found a starter by DB Electronics for 61.00 as opposed to 374.00 from Yamaha. I have a DB gear drive starter on my truck that has worked well for years. If I don't find anything after a voltage drop test, I may go with the DB. The armature is about 175.00 from Yamaha.


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## ET101 (Sep 10, 2020)

Yeah yamaha is proud of that starter... I went through ebay. I discovered that this f40 shares a lot of the same parts as the competing mercury.


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## ek02 (May 8, 2012)

I'm seeing that too. The starter relay stopped passing current and would just click. I priced the Yamaha relay at 56.00. EBay had one for 15.89. Fits Merc and Yamaha. I plan to do some more diagnosis tomorrow in between other projects.


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## ek02 (May 8, 2012)

I took the starter apart again and checked the armature per the shop manual with an ohm meter. Checks out good. I did a voltage drop test on the cables. It drops less than half a volt. I hooked up my old Sun VAT tester and the starter draws 300 amps when it hesitates, but only 110 amps when it starts cranking. Looks like new starter time even though the armature tests good, brushes are good, and the bushings are all good.


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## ET101 (Sep 10, 2020)

What was your voltage drop from the starter cable to starter case?


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## ek02 (May 8, 2012)

The cable from the solenoid to the starter had a .300 volt drop. My next move is to swap the known good starter from our other engine. Since I can easily turn the flywheel with a ratchet, I don't think it is an engine problem.


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## ek02 (May 8, 2012)

I swapped the starter from the 40 we use all the time and it spun over perfectly. This is a spare high hour engine that I repaired a broken driveshaft in the lower unit on, so it will get the DB Electrical starter. The old starter has a sticker on it that says it was made in 2011 so it is not original. The starter from our good engine used to hesitate like this one but cleaning and lubing it fixed that. No luck on this spare engine even though it all checks out. The armature must have a bad winding.


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