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BruceS · 27-04-2016, 15:15

Started & died?
Most Gennies will die within a short time if any number of things aren't satisfied.
Oil pressure.
Exhaust temp high. (no water)
Genny output.
Short circuit in output.
Output too high.
Output too low.
Look up "watchdog".
I'd check the oil pressure sending unit first. (or jump it)

**a64pilot** · 27-04-2016, 15:20

Quote:

Originally Posted by Cadence

I can not imagine that type of draw on a starter for a gen. of that size. As fare as load, you don't start a gen. under load. JMHO

No, but since there is no clutch or other way to disengage the generator head, it is sort of like starting an automobile in gear as the starter has to overcome the inertia of both the engine and generator and accelerate both. Just like I'd bet Lunch that my single cylinder always stops right at the beginning of the compression stroke, so the starter has to deal with compression right as its beginning to accelerate the engine.

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tinkrman69 · 27-04-2016, 16:07

When troubleshoot a starting problem the test in order are: battery voltage 12.5, battery voltage whilst cranking 11.5 - 12, voltage at starter 12.5. voltage at starter whilst cranking 11 - 11.5...all systems acceptable. So voltage at starter whilst cranking should not be less than 11 volts 11.75 is best. If the voltage drop is more than one volt betwixt the battery and the starter the cable is insufficient. either too small or too old. It'll probably work fine....for a while...with 1.5 volt drop, but you'll take life out of the starter.

this is all assuming that the battery has sufficient cranking amps (CCA) 650 CCA would work with pristine conditions. 800 CCA would give the most versatility...ie...old connectors, high humidity, cold temperatures, low charge..... if the CCA of the battery are too low, the tests above will be wrong. if you had a 24 volt system the voltage drop test would be the same .5 to 1.5

a 15 foot run one way? 1/0 would be about right, measuring round trip...ie...positive and negative runs from and to the battery. usually I try to mount the cranking battery as close to the starter as possible. Less load and aging on the circuit. the wires in a circuit are part of the load, not just the motor. Hence the voltage drop. 15 foot oneway is a long ways for a cranking battery. My cranking Battery is only 7 feet oneway - Pearson 424.

smac999 · 28-04-2016, 00:29

nobody does a starter at 3%.

I'd say 1-2v is pretty normal. which is like 10-20%. but of course not ideal.

I would aim for 10%

2awg is pretty common for smaller gens.

I fuse them at 200-300a with MRBF's

should have own battery and battery switch. going off an engine starter post is just silly.

sailorboy1 · 28-04-2016, 03:47

color me silly

**a64pilot** · 28-04-2016, 04:58

Quote:

Originally Posted by smac999

should have own battery and battery switch. going off an engine starter post is just silly.

Why? If your going to say you need a third bank just in case your first two die, then of course you should have an independent fuel supply too

sailorboy1 · 28-04-2016, 05:20

Quote:

Originally Posted by smac999

nobody does a starter at 3%.

I'd say 1-2v is pretty normal. which is like 10-20%. but of course not ideal.

I consider this thread dead really as far as helping me. But, my original wiring worked out to 15% and the generator wouldn't spin.

**a64pilot** · 28-04-2016, 05:43

Quote:

Originally Posted by sailorboy1

I consider this thread dead really as far as helping me. But, my original wiring worked out to 15% and the generator wouldn't spin.

It may help others, and the information that at 15%, it won't start is I believe good info, it sort of tells me that 10% while it works may be marginal, and I believe the less loss there is, the longer a starter will last, cost a little extra money, but kind of hard to go too big with battery cables

sailorboy1 · 01-05-2016, 16:29

It started right up this weekend and I didn't do anything. I ran it an hour plus and it powered the reverse cycle air conditioner and warmed the boat. But it would occasionally slow and then come back to speed. So I'm going to run a separate fuel line for it which will reduce the fuel hose length. Of course that means a separate fuel/water filter unit and more $$$ into this project.

Good thing my labor rate is just beer.

**a64pilot** · 01-05-2016, 16:37

First indication I get of a clogging fuel filter on mine is it will bog down under load, I fist ran just a 2 micron filter and after clogging two, decided to plumb in after the 30 micron Racor for the main engine.
Maybe you have a fuel restriction, not enough flow?

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sailorboy1 · 01-05-2016, 16:55

Quote:

Originally Posted by a64pilot

First indication I get of a clogging fuel filter on mine is it will bog down under load, I fist ran just a 2 micron filter and after clogging two, decided to plumb in after the 30 micron Racor for the main engine.
Maybe you have a fuel restriction, not enough flow?

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I'm already coming off the main engine Racor line. That makes the loop about 30' from the tank to the filter and then to the generator. I'm going to install a new Racor filter and run it right off the tank which will shorten the line to about 10' each way. I never really liked the idea of having the generator fuel connected to the main engine supply line anyway and was probaby a stupid thing to save $80.

Cadence · 02-05-2016, 08:14

Quote:

Originally Posted by sailorboy1

It started right up this weekend and I didn't do anything. I ran it an hour plus and it powered the reverse cycle air conditioner and warmed the boat. But it would occasionally slow and then come back to speed. So I'm going to run a separate fuel line for it which will reduce the fuel hose length. Of course that means a separate fuel/water filter unit and more $$$ into this project.

Good thing my labor rate is just beer.

Are you sure it isn't slowing down when the heat pump compressor kicks in?

Could be compressor start up load slowing it periodically.

**a64pilot** · 02-05-2016, 08:20

Run two filters, one 30 and one 2 or you may be like me and get only about 10 hours or so out of a filter before it clogs.
I ran a little Racor 120 filter, I even put on on my outboard as it's the same parts of course.
Check with Hopkins Carter, he may can give you a deal on two of them as I believe you have to filter to 2 microns, and to do that you need maybe a 30 micron first or the 2 micron clogs early.

Or maybe stay with what you have and install an electric boost pump, that should fix the issue too.