Two Things Hunter 49

[Georgedoyle]

First thing: I finally got around to installing my Gori three blade folding prop and promptly sheered one of the lag screws that hold the motor mounts to the stringer. It was the forward starboard mount. I replaced it with a new screw half an inch longer. The new screw seems to be firmly in place and it has a longer shoulder to take the sheer forces, but I'm thinking I might need two screws. The single 3/8 lag does not inspire confidence. I’ll be replacing all of my mounts soon and would like some input. Also, are the mounts identical all around or are they a different spec at each corner? I've read conflicting reports. Yanmar 4jh4 HTE.

Second thing: while working on my engine mount fiasco, I noticed that my Balmar alternator pulley was very hot, like too hot to hold your hand on it. The case was also hot, but not as hot as the pulley. The engine was not running and hadn’t been running for two days. I was not plugged in to shore power, and the generator was not on. The only thing that was running was the solar charger. I checked all of the wiring, the batteries, and the mppt, but nothing else was hot. When I turned the starting battery switch off, the alternator cooled down. What's going on?

 

[jssailem]

Usually you need the key on to provide power to excite the alternator.

Sounds like you may have an internal short. Do you have a battery monitor. Are you discharging the battery into the alternator when the switch is on?

You need to resolve this now, before you go out sailing.

 

[Georgedoyle]

That was it. The key was in the switch and turned to the right one click. We left it like that for a few days. We were checking the motor mounts by turning on the engine and putting it into gear. That was when we found the sheered off bolt. We were distracted by the bolt failure and never got back to the key. I hope we didn’t damage the alternator.

 

[Georgedoyle]

Next time we go down to the boat we’ll confirm that the key was the problem. Thanks.

 

[Ralph Johnstone]

Any chance you've got an external alternator reg. which will have a temp. monitor for the alternator ? You can check the temp. there or just shoot wiht an IR gun to give us a better idea of "hot". After 2 days of heating, the batteries should be somewhat drained.

Now THIS is interesting.

 

[Georgedoyle]

The batteries were fine. The solar was charging during the day. We have the ARS-5 controller. I didn’t check it for temp. It was hot like a piece of metal sitting in the sun all day. Too hot to handle for more than a second or two, but not hot enough to melt the belt. It's interesting that the pulley was a lot hotter than the case. As soon as I turned of the battery switch it all cooled down so at least it was safe to leave the boat.

 

[Tally Ho]

First thing: I finally got around to installing my Gori three blade folding prop and promptly sheered one of the lag screws that hold the motor mounts to the stringer. It was the forward starboard mount. I replaced it with a new screw half an inch longer. The new screw seems to be firmly in place and it has a longer shoulder to take the sheer forces, but I'm thinking I might need two screws. The single 3/8 lag does not inspire confidence. I’ll be replacing all of my mounts soon and would like some input. Also, are the mounts identical all around or are they a different spec at each corner? I've read conflicting reports. Yanmar 4jh4 HTE.

Second thing: while working on my engine mount fiasco, I noticed that my Balmar alternator pulley was very hot, like too hot to hold your hand on it. The case was also hot, but not as hot as the pulley. The engine was not running and hadn’t been running for two days. I was not plugged in to shore power, and the generator was not on. The only thing that was running was the solar charger. I checked all of the wiring, the batteries, and the mppt, but nothing else was hot. When I turned the starting battery switch off, the alternator cooled down. What's going on?

The bolt sheered because the new prop had so much more bite it twisted the engine enough to break a lag bolt?

Greg

 

[Georgedoyle]

That what it seems like happened. As I watched the engine while it was put into gear, I could see that the the forward starboard mount took the brunt of the force from the prop engaging. The new lag screw held, but I'm not sure if it will last.

 

[SEMPERAVANTI41]

Have you checked the tightness of the remaining lags? Perhaps the sheared lag was loose.

 

[Georgedoyle]

I checked and tightened everything. One lag would not tighten. It was spinning, so I drilled the hole deeper and threaded in a longer screw. It tightened up nicely. All others were tight. I got a quarter turn on a few of them, but that's it. The port front engine mount bolt was loose, though- the one stud that captures the actual Yanmar mount. I tightened this.

 

[Georgedoyle]

The sheared screw was in a slotted opening on the engine mount foot. I suspect it was loose and was hammering against the slot for a while until it finally cracked. The prop might have contributed. It seems to have a lot more torque than the fixed blade.

 

[artboas]

The sheared screw was in a slotted opening on the engine mount foot. I suspect it was loose and was hammering against the slot for a while until it finally cracked. The prop might have contributed. It seems to have a lot more torque than the fixed blade.

Yikes!!
I would really suggest a rebuild of the mount area. One suggestion is to glass in some threaded aluminum plates, which you would also lag down for extra stability
Question …
Why did you go with the Gori prop versus maxprop or Variprop?
Does your Gori prop have the “overdrive “ feature?

 

[Georgedoyle]

Well, I went down to the boat today and confirmed that the alternator does not get hot with the battery switch on and the solar panels charging. The batteries were low (12.2 volts) though, and the solar controller showed zero amps charging the starting battery. It showed 8 amps charging the house battery. I watched it for a while. It seemed to come up a little after I switched on the starting battery to 12.3 volts. Usually, the solar system keeps the batteries above 13 volts. Did I turn off my charging system by switching off the starting battery? Or did I damage something by leaving the key switch on?

 

[Davidasailor26]

12.2 V is pretty low for batteries at rest. The starter battery shouldn’t really have any persistent load on it so it should be floating closer to 12.7. You’ll need to trace your wires to confirm, but it could definitely be the case that the starting battery will only charge if it’s switched on.

 

[Georgedoyle]

Okay, here's an update. I took the alternator to get checked out after the key switch disaster. It needed a new rotor, $200. Also, my ARS-5 regulator was shot, $300. Of course the battery was a goner after being completely discharged and still connected to the load for several days, $300. So that was an expensive lesson. Always take your keys out of the ignition when not actually running the engine.

 

[Georgedoyle]

I got the engine mounts changed. Then I replaced the impeller while it was accessible (it was in great shape after four years), installed the alternator, hooked up the new regulator, changed out the starting battery, and aligned the shaft. Then I took the boat out for a spin. Everything works great. The engine mounts look solid, and there is very little vibration from the prop. The Gori backs up beautifully. I now can face the stern and drive backwards, steering as if I were going forward, and the boat tracks in a straight line. I pulled into the slip this way with a little bit of thruster input to swing the bow around with no problems. That’s a big improvement over the original prop. I still need to go into the advanced programming and adjust the settings on my ARS-5, but it was a long day, and the programming takes some patience. Let me know if anyone has a cheat sheet for this. I have three Lifeline 8D AGM house batteries and one group 31 starting battery.

 

[jssailem]

Congrats to you for these accomplishments.
It is a great feeling when a plan comes together and is executed to success.