Shibaura Engine running generator

[WranglerX]

Is there room in generator compartment for a single 500 CCA battery and new (short) cables?

How clean are all cable and connections at batteries, any corrosion or are they all clean shiny and protected with anti oxidation grease....

Also I believe 30 feet of cable between batteries and starter is BS...

Dale

 

[Industrial Toys]

It can all be measured with a load tester.

I once bought a carbon pile tester at Princess Auto (CDN HF). The first time I used it, I just heard crackling inside, then the unit became NF and had bits and pieces rattling around the inside. I was as amused as I was pissed.

 

[zzvyb6]

The start attempt in your video sounds EXACTLY like my snowmobile sounded when I had a problem. Replaced the starter and it's fine now. Apparently there were several open windings on it.

You can tell by the unloaded rpm if you pull it out (again) and watch and listen. A good starter will just about jump off the table and hit peak rpm immediately. A bad one will be lazy because of the reverse emf from the bad windings fighting the good ones.

 

[KenMT372d]

Did you have any of the battery cables with corrosion in the past that you have cleaned up already? Why I ask is I have seen the corrosion eat up into the battery cable many inches even a foot or more into the cable so the corrosion could not be seen. One person I know replaced all 4 four batteries and starter still to have the same problem with very slow cranking of the engine & very hard to start. We found the one bad battery cable by checking the voltage drop across each cable (one cable at a time in just a few minutes ) as the engine was being cranked. One of the cables had a 2 to 3 volt drop when it was handling the cranking current. You should not see more that a fraction of a volt drop across a good cable or cable connection to the battery. You have to check both the (+) battery cable(s) and (-) battery cable(s) path for voltage drop when cranking. This person had spend over $600 in batteries and starter when the only problem was one $10 foot long battery cable between two of the four batteries. Also one other item to check is that you have a good heavy gauge ground cable ( - battery connection ) to the generator engine block from the RV's frame and from the batteries to the the RV's frame. Have seen problems that the batteries negative (ground path) using the RV's frame have one of the ground cables missing. The starter motor did not have a good negative (ground) return path to handle the cranking current needed to get back to the batteries. Must have a complete high current path with little to no voltage drop on both the (+) and (-) side of the cranking circuit. Best way to test is place one of your voltmeter leads at the center of each (+) battery post (one at a time) not the cable clamp and the other voltmeter lead at the starter motor connection, crank the engine and check the voltage drop. Then after you have check the (+) current path for voltage drops the do the same for the negative ground path. Test from each of the negative battery posts to the starter motor case (engine frame and starter motor should be the same) looking again of a larger voltage drop when cranking the engine. Have found a missing the "heavy gauge ground" wire that had been replaced with a 12 gauge wire, not going to work needs to be at least 4 gauge or larger. Good luck finding the problem, hope to hear what you find out.

 

[daugen]

Large diesel motorhomes either have a generator in the rear side compartment or up front in a slideout.
Space is an issue, and from quite a few years rv'ing I've seen rigs with and without separate starting batteries.
Because a 40-45 foot motorhome is so long, yeah the runs from battery compartment all the way up to front are problematic, which
is why many slide out front gens have a separate starting battery. The idea of a having a dedicated strong starting battery just for your generator
is a good one, if layout allows.

Some battery compartments are closer to the front, under the entry steps. Some are wherever they find room for the batteries.
The OP's set up sounds like a normal motorhome. Having a dedicated deep cycle battery bank just for house power is ideal, and a separate
battery just for the gen.

In my old boat I had a switch that would connect one bank of 4 8V batteries to the second identical bank, 12V and 32V system.
Lot of batteries. But if one engine wouldn't start due to low batteries, a flip of the switch and the second bank took over.
I wonder if the OP has any such little switch in there. One hopes the setup is bone stock. If the prior owner started "customizing", you
have even more detective work to do. Every connection is a point of failure, but I think by now OP is used to taking every single thing
apart on that motorhome. Sounds like me rebuilding a boat. Everything is suspect, you trust nothing.

With more sleuthing and diagnosing, I'm sure he'll get it.

 

[zzjea]

Thanks for the continuing useful comments and advice. My plan today is to go to Harbor Freight this AM and get a 100 Amp 6/12V Battery Load Tester. It's only $20 so what the heck.

I will take the starter (+) cable off the starter contact and connect a heavy duty jumper cable from the starter to the battery in my car while the car is running producing 14v from the alternator. I will connect the (-) jumper to the genset frame and let the sparks fly when touching the jumper to the car (-) battery post. This will eliminate all of the questions regarding my MH batteries and wiring. If the starter runs like crazy then I will try priming the glow plugs and fuel pump by pressing the preheat button. The genset circuit will still have 12v power from the house batteries so that circuit should activate and the engine should start. If it does not, then the problem is with either the glow plugs or the solenoid that activates them. I know I am getting at least 12v to that circuit from the house batteries. My earlier test showed the glow plugs to heat up but I don't know the amp draw on them. I don't suspect the fuel pump as the genset runs perfectly if it will crank. The glow plug/pump solenoid is the only thing I haven't replaced. If that solenoid or glow plugs are causing a large amp draw it would drain the amps needed for the starter under the original MH circuit. By isolating the power to these 2 circuits and solenoids, I hope to determine where the drain is. I think it is a drain of amps somewhere at the genset, not the long house battery run. This all used to work at one time.

I plan to use the Load Tester if the above doesn't pinpoint the problem. Again, this is not a tractor where most things are easier to get to. I am working under the MH with about a foot of clearance into an opening on the bottom of the genset that is about 14"x10" and all of the electrical (starter/solenoids/etc.) are tucked up in there upside down for me among water cooling hoses etc. Just saying. Nothing is easy to get to except for the starter (+) terminal. Just testing from point A to B in that space is a challenge in itself. The video I provided earlier was from the front that is easy to get to, but the electrical is not up there, it is down under...

I am determined to solve this problem. Any comments before I begin?

I'll let you know what happens.

 

[zzjea]

The Ziller forum (Generac) had this comment:

"Just a shot in the dark here, sometimes those diesel will use a decompression lever, is it possible you have an automatic one that is not functioning? Also just because the cables look good, don't overlook them, corrosion can
get underneath the sheathing."

Is there a decompression lever on this Shibaura?

 

[Industrial Toys]

I would be very doubtful. My single cyl air cooled Yanmar has one.

 

[zzjea]

Update. Just got back from the MH and testing. I ran the starter directly from the car's battery (14v) to (+) terminal on the starter and clamped onto the starter mounting bracket. No joy. Same results. It took me an hour to get one bolt of the 2 off the starter to remove it. It is behind the starter out of view and a retaining nut that is harder to get to with a wrench. I suspected the starter since I bypassed everything else. I tried the starter while it was laying on the ground with jumpers and it ran as I think it should, no resistance and spun as long as I applied power.

So then I began thinking it must be grounding issues between the starter housing and the frame ground. On looking closely at the starter mount flange and the corresponding receptor on the frame bracket, they both appear not to be steel but look more like aluminum as they are a gray color and there is corrosion on both of these that is not rust. More like a chalky weathered look. I filed some of the flange and it is now a smooth and shiny silver color. I thought I would get the starter tested but now I am leaning toward negative connection issues with the starter and the frame. The starter has some carbon residue around the shaft which probably is from it trying so hard to turn over. About a year ago, I suspected this type of issue so I put a separate ground wire (battery cable) from the chassis frame to the starter. However, I made the connection on the outside of the starter bracket where the bolt goes through to a nut. If I had put it on the other side nearer to the starter, it might have worked. But the corrosion/oxidation would have still been there.

Since 1 of the 2 mounting bolts is almost an hour long process, I do not want to do this very often if ever. Obviously I will clean with a file and wire brush the areas where they contact on the grounding side. I can add a few pictures in next post.

An thoughts on this theory? I did not get the Load Tester yet as HF was farther away and I wanted to see if jumping would start directly to starter.

 

[zzjea]

These are views of the starter and the frame mount, both of which have corrosion. The frame mount is attached to a steel bracket and is also a gray color.