chasing a gremlin.....

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jopete
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chasing a gremlin.....

Post by jopete » Sat Jan 30, 2016 2:58 am

boat started acting up. my battery guage is all over the place. boat starts fine for a day, then won't turn over but half a turn.
my voltage and battery guage drop when i hit the starter. checked all the ground wires, shook the wires under the console, and it started like new. lol
took me a hr to get it to turn over 2 days ago, when it finally did it started up fine, spun like a new one.
had battery load tested, tested fine.
shook the fuse box and voltage was in/out. so i just finished putting in a new fancy fuse block. hit the starter and it made half a revoloution and stopped.
oh, i forgot to mention that the starter made a weird noise like it was disenguaging with the flywheel when i tried to start it.
in the am i will try fresh battery. then i guess i will try to find out what kind of starter it is and get a new one.

if it ain't the starter or a battery cable, i might have to get my buddy down the street to look at it.

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CactusJack
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Re: chasing a gremlin.....

Post by CactusJack » Sat Jan 30, 2016 4:59 am

Try clipping a jumper cable from the block to the - of the battery in case the starter isn't earthing properly.... It will prolly be something painfully simple. If you put a + to your coil and start it (carefully) with either a screwdriver across the positive and crank wire at the starter to see that it is operating/engaging correctly then if it is fine, keep looking under the dash, including checking wires for continuity. Is it a car motor or airplane/gpu?

If all seems fine, I would be trying another battery, sometimes new ones aren't real good either... check battery terminals for clean and tight.... it sounds to me like the starter is sometimes not getting enough juice.... if you haven't already, fit a starter relay... so the starter solenoid is getting full battery power, without all of the voltage drop from multiple connections etc :wink:
Last edited by CactusJack on Sat Jan 30, 2016 8:44 am, edited 1 time in total.
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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Re: chasing a gremlin.....

Post by Gary S » Sat Jan 30, 2016 6:55 am

I replaced a starter and got in a argument with a salesman at Advanced years ago because of a bad battery terminal. Jack is right with the jumper cables, can save yourself some headaches. Used a jumper cable from battery to engine block. engine turned over fine. The terminal looked perfect but when I cut it in two it was corrosion insulating the terminal from the wire. So take the cable off battery before you use the jumper cables.

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jopete
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Re: chasing a gremlin.....

Post by jopete » Sat Jan 30, 2016 8:50 am

sorry, it's a GPU. changed out starter button yesterday as well.
now that i got a nap, i'm gonna go try those suggestions and see if i can get her to crank up. last weekend of deer season and i'd like to make a evening hunt.

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Re: chasing a gremlin.....

Post by mojoe » Sat Jan 30, 2016 9:23 am

I had a battery that had top posts and side terminals. The starter was attached to the side terminals. Worked good for about a year then quit. Everything checked out, including the battery. After much :banghead: I jumped it to the post and it started fine. Turned out the terminal was shorted out inside the battery but the post worked fine.

Good luck getting her running for tonight.
Mark 7:9

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CactusJack
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Re: chasing a gremlin.....

Post by CactusJack » Sat Jan 30, 2016 10:25 am

I once bought a new battery, those sealed ones that were red and blue.... you could have them any way up (ie: expensive) At the shop, I installed it in my car, but I was a bit too hard on the terminal nut when tightening it and I heard a click... sure enough,,, I had snapped it off inside the battery... it would work only if I pushed down on the terminal :roll:

Lucky the guy at the shop said they had had a couple of duds and replaced it.... my point being... those old hard cased batteries were strong (and heavy) and had real lead in them.... the new batteries are junk... they have a plastic trellis that is dipped/coated in lead paste... not even real lead.... just paste :shock: :roll: so it don't take much for a chunk of the paste to fall off the plastic mesh inside and you drop that cell....

The weak plastic on our batteries now, mean you have to be real gentle with tightening and loosening the terminal bolts and even pulling a tight terminal off.... so easy to bust it inside. That is why even a brand new battery can be no good from day one.... If you have a dead battery sitting somewhere waiting to go to scrap, crush a terminal with some multi grips... they are hollow plastic coated with lead.... you can rip the terminal clean off without trying too hard at all.... junk

Other interesting stuff about batteries, the reason they go flat is coz the acid/electrolyte needs to be in contact with the lead.... but as a battery is used and begins to go flat, it is because the plates 'sulphate' and stop the acid getting to the lead.... so you get less and less charge. When you charge a battery, the electricity at 50 or 60 Hz vibrates the plates and the sulphate falls off resulting in maximum charge. With modern (crap) batteries, especially the really cheap, very light weight ones, it is easy to knock lead paste off the internals... That is why it is bad for modern batteries to get dropped, even knocked too hard, to overcharge (vibrates the plates too much), the plastic internals are weak.... if they sit too long flat.... all in the interest of you and I having to buy more batteries :roll:

Usually you can tell the quality of a battery (lead acid) by how heavy it is for its size.... if it is very heavy, it must have more lead at least... if you pick up a battery at a shop and it feels really light weight.... guess what it wont have much of inside :lol:
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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jopete
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Re: chasing a gremlin.....

Post by jopete » Sat Jan 30, 2016 12:34 pm

i remember reading several times on southern airboat about folks having all kinds of trouble when chasing problems when they just tighten the ground wires instead of taking them off and cleaning them. well, i am guilty.
this morning i headed to the boatshed with jumper cables, but before i tried them, i took off every connection on the airboat that i could think of in the starting circut, wirebrushed everything, and tightened them securly. i found a previously unknown to me ground wire from cage to stand that looked pretty questionable. i also added a new ground wire from engine block to the cage.
cleaned all connections on the starter and alternator while i was there.
checked prop bolts and various engine and rigging bolts.
hit the button and it turns over/starts like normal. i do hear a little noise when the starter enguages, i think it has some wear on starter gear/flywheel from losing voltage and disenguaging.
we will see how it does in the swamp today.
the good news is now i know where every wire on my boat goes. and i have a new fuse block and several new parts.
i'm running a 5 month old now bluetop battery. i been looking for reason's to dislike it, but it's been great so far.

thanks for all the help, southern airboat is by far the best group of gentlemen out there!!!!!

headed to the woods........

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jopete
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Re: chasing a gremlin.....

Post by jopete » Sat Jan 30, 2016 10:14 pm

boat ran fine this afternoon. stopped and started it about a dozen times. fired right up.
nav lights never been so bright. lol

oh, ran the deer off my stand when i drove up. they were there all morning. got to love game cameras!!!

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Re: chasing a gremlin.....

Post by Gary S » Sun Jan 31, 2016 6:39 am

I prefer my ground to go straight from the battery to the engine.

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CactusJack
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Re: chasing a gremlin.....

Post by CactusJack » Sun Jan 31, 2016 9:29 am

That's great news Jopete.... I knew it had to be something simple. Now you have it right, blob some grease or vasoline on your terminals and rub it in... leave a nice heavy coat of it.... & on the bolt/nut where it bolts to the motor or motor mount too.... keep that white gunk from happening coz air and moisture cant get at it :)

glad you caught that dang gremlin :D
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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jopete
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Re: chasing a gremlin.....

Post by jopete » Sun Jan 31, 2016 1:45 pm

my ground goes straight from battery to the engine block. from there it goes to engine stand, cage, and then fuzebox negative.

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Deano
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Re: chasing a gremlin.....

Post by Deano » Sun Jan 31, 2016 6:39 pm

CactusJack wrote:. . . Now you have it right, blob some grease or vasoline on your terminals and rub it in... leave a nice heavy coat of it.... & on the bolt/nut where it bolts to the motor or motor mount too.... keep that white gunk from happening coz air and moisture cant get at it . . .
Jack, Don't you guys have something like this down there ?

Image

I only apply/use this stuff after I've just thoroughly cleaned everything.
It won't correct or fix anything, but it can and will increase the longevity
of existing good, solid connections.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan

barhopper
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Re: chasing a gremlin.....

Post by barhopper » Sun Jan 31, 2016 8:13 pm

I had to replace the fuse block in mine and redo the console ground when my gauges were jumping around. It always started though.

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mojoe
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Re: chasing a gremlin.....

Post by mojoe » Sun Jan 31, 2016 8:26 pm

From the block to the battery is the most reliable. But with mags, I worry that way. I like the ground from the block to a switch then to the battery. That way I feel safer when I'm in there if I turn the switch. ( a lot of people like perko switches, I like an old school circuit interrupter with a remove able pin) And everything else goes to the rigging which also goes to the same switch. That way the mags can't find another circuit to (fry) ground through. Off is off!
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Re: chasing a gremlin.....

Post by Gary S » Mon Feb 01, 2016 7:37 am

My mag grounds are independent of the electrical system. Each mag has its own ground wire from mag case to switch and back to the p lead. If I understand what your writing, when you open the switch, your mags are hot and ready to fire. I don't use battery switches never found a need fore them. If I am working around prop I remove the positive battery cable.

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Re: chasing a gremlin.....

Post by mojoe » Mon Feb 01, 2016 9:18 am

Please, correct me if I am wrong: I thought the mags default to "on" and the switches turning them "off" is actually connecting a ground to short them to the battery negative instead of through the plugs.

If I am right, relying on that switch alone does use a ground to disable the mags, but that is not the same as a switch that disconnects the ground from the block to the battery. The same block to battery ground you starter uses is also the ground your mags use to run. So, in theory, if a mag switch is broken or a wire shorts or a connection goes bad on you mag switch, you mag is "on" when you think it's off. A switch disconnecting the block to battery ground means off is off even if something goes wrong with you mag grounds.

Of course, I could be way off here, but that is my understanding.
Mark 7:9

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jopete
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Re: chasing a gremlin.....

Post by jopete » Mon Feb 01, 2016 10:14 am

yep, when i work around the prop, perko switch is off, positive wires pulled off the battery, and all switches off on panel.
guy about 2 miles down the road had 1 leg cut off below the knee by a prop about 30 years ago. I knew him for years before i ever noticed it.
he got lucky and he didn't bleed out while waiting on somebody to pass by and get him some help.

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Re: chasing a gremlin.....

Post by Gary S » Tue Feb 02, 2016 7:51 am

The switch that turns you mag off closes to turn it off. If you have the little plate that comes on a toggle switch on it, it will read on when the mag is off. You have to complete a circuit to ground to turn a magneto off.

The same block to battery ground you starter uses is also the ground your mags use to run.

A mag doesn't need a ground to run.

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Re: chasing a gremlin.....

Post by Afflicted » Tue Feb 02, 2016 9:42 am

Always check out your GROUNDS when head scratching a battery issues

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Re: chasing a gremlin.....

Post by diamondback0320 » Tue Feb 02, 2016 11:10 am

Unless I'm reading this wrong where someone said take posi cable off..mags do not need a battery to fire,in most cases a battery is only for electric fuel pump..lights etc. Correct? If your battery dies & you have a outboard pump ball you can still fire ur mags & make it home,atleast that's what I've always thought

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Re: chasing a gremlin.....

Post by CactusJack » Tue Feb 02, 2016 11:22 am

diamondback0320 wrote:Unless I'm reading this wrong where someone said take posi cable off..mags do not need a battery to fire,in most cases a battery is only for electric fuel pump..lights etc. Correct? If your battery dies & you have a outboard pump ball you can still fire ur mags & make it home,atleast that's what I've always thought
Yeah, that is why people need to take off spark plug wires if planning to turn the crank of a motor on the bench... it might fire if it has mags and plug wires connected....

A few gyrocopter folks have lost bits and pieces of themselves to mac engines firing if the prop is moved when the engine is on a motor stand for working on... :shock: :cry:

And the old lawn mowers... they say don't turn the motor by the blades underneath (when cleaning) coz it could fire.... which might end with you 'throwing in your hand' :lol:
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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jopete
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Re: chasing a gremlin.....

Post by jopete » Tue Feb 02, 2016 1:27 pm

it wasn't the boat running that was my problem, it was starting it. lol

i figured i would just hand prop it if it came to that or be stranded, but i always got it to eventually turn over.

been running good the last couple days. hunting season over now.

been frogging the last 2 nights.
finally found them and now it's raining and a cold front comming. just my luck!!

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Re: chasing a gremlin.....

Post by broncobill » Tue Feb 02, 2016 2:11 pm

Had the same problem. It finally raise it ugly head.
Had gear reduction starter. Wire inside solenoid
Broke but was still touching and would start
Sometimes other times it would buck or do
Nothing at all.

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Re: chasing a gremlin.....

Post by mojoe » Tue Feb 02, 2016 2:28 pm

Hmmmm?

I gotta rethink safe wiring. So what you're saying is that the spark from the mags dissipates into the block and dosent need the ground from the block to the batt neg to fire? Then, if everything, including the mag grounds, went to a switch, when you turn the switch off, the mags would then be turned back on?

If you put everything BUT the mags on a switch on the negative, when everything else is off, if you try to start it(mags grounded) the starter frys the mags because the full amperage goes out the mag ground(melted a set that way). So that can't be the right way to wire it.

So the switch goes on the positive? And the only true way to shut off the mags is to unplug all spark plug wires?

Hmmmmm?
Mark 7:9

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Re: chasing a gremlin.....

Post by diamondback0320 » Tue Feb 02, 2016 3:12 pm

I'm no expert in electrical that's fer sure but mags are always HOTT unless grounded thru a switch of sorts,if ur battery is dead nuts..meaning you have no starter or fuel pump(electric), if you're mags switches are on or your pleads are not plugged in the mags are hot or same scenario you have a faulty mag switch that mag is hot & will fire,unplugging the plug wires just keeps fire from reaching the cylinder, jopete I understood what your thread was about.. Was just reading a response of somebody talking bout taking off positive cable when in around the motor I guess believing that that has any affect on the mags..which does not,I think lmao!

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