Balmar alternator on Yanmar 3ym20

[SycloneDriver]

Today I stated the process of installing a Balmar 60 series 100 amp alternator onto my Yanmar 3ym20. I've already hit a few bumps in the road.

1. The hardware kit that was included with the alternator/regulator isn't very complete. Looks like I'll need several new bolts. I could get by with the the factory front pivot bolt but the rear is too short.

2. I'm not positive but it looks like I will need to put a spacer in between the adjustment arm and the alternator. I think one was in the hardware kit. My back was bothering me at this point so I called it a day.

3. The arc of travel is different for the new alternator and will require loosening the adjustment bracket at both ends every time the belt needs tensioned. Not a big deal.

4. The ground lug on the factory harness is too small. Again, not a big deal but I forgot my lugs.

5. The new alternator is larger and interferes with the Yanmar alternator bracket. It won't allow the alternator to adjust in toward the engine as far as the old one. The factory belt is now too short. I forgot the bring the belt home or take a picture of the belt number. Anyone know what I have or need?
*Edit* I could grind the bracket to allow more adjust but then the positive post on the alternator would contact a bolt head on the engine, so I won't be doing that.

Here are a few pictures.

 

[SycloneDriver]

More pictures.

Edit. Looks like I took a picture of the belt # after all.

 

[dLj]

I'm still looking for the "simple" boat project that really is "simple"...

dj

 

[SycloneDriver]

Today I got it installed. I'm currently using the internal regulator. I did this because it was easy and my back was bothering me. I will add the external later.

For this install I purchased an old style GM alternator plug. This allows the tach to be driven without cutting any wires.

I replaced the two pivot bolts with hardware store bolts. 10 x 25 and 10 x 30 if I remember correctly. The factory rear bolt is too short and must be replaced.

I swapped the 38" belt for a 39".

I had to crimp larger terminal ends on the ground wires.

I installed one washer between the alternator and the adjustment arm. That said I have not actually checked the belt alignment.

I did a short test run and it charged well but only at 13.35 volts. The intenal regulator is supposed to be set at 14.1v. I must have a bad connection somewhere.

Things still to do.
1. Find and fix bad connection.
2. Upgrade ground cable.
3. Check belt alignment.

Note, the smaller bolt in the photos is too short. I should have bought one equal to the other end of the factory bolt. This bolt attaches the coolant hose bracket to the engine.

Note 2, I chose not to reuse the factory belt guard/cover. This simplifies maintenance and should increase air flow to the alternator.

 

[SycloneDriver]

Today I finished replacing the factory alternator adjustment arm with heim joints and a sleeve. It wasn't as simple as it sounds but it should work great. I stole the idea from another member, thanks other member.

 

[jssailem]

Is that a picture of your helper there?

 

[SycloneDriver]

Yes, he was lots of help.