replace all Yamaha carbs Chapter 2

colayn

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Re: replace all Yamaha carbs Chapter 2

didn't finish with work until late last night, so haven't ran the test on the charge coil yet.
Question, looking for the short to grd , I assume you mean using my multi meter ?
I don't have a meggar
 

rodbolt

Supreme Mariner
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Re: replace all Yamaha carbs Chapter 2

yes your meter.
its a dirt simple 2 wire coil with an iron core that we spin a magnet around.
you know what that is ?
 

colayn

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Re: replace all Yamaha carbs Chapter 2

yes, I completely understand the coil and its operation.
I just didn't know if you typically seen dead shorts that the 9v output of the meter can find or you expect more resistance, like small holes in the insulation which require the higher output of the meggar to find.
 

colayn

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Re: replace all Yamaha carbs Chapter 2

high speed charge coil voltage is way off, you either did the test wrong or you have a stator issue.
remember, the spec is MINIMUM.
220 isnt bad for low speed charge coil output.
no sense in lake testing until you find out why the high speed charge coil voltage is so low.
check each high speed charge coil lead for shorts to ground and the resistence between both leads.

My manual doesn't give resistance for the charge coils, I have looked everywhere. But going by the test sheets Don S posted earlier
Low should be 740 ohm and high should be 69
My actual is low 702 and the high side appears to be open. I checked as high as 200M and still open.
I want to get the flywheel off and take a good look at the wiring but I can't get the fly wheel off.
Have removed the nut and washer and using my puller and 3 - M8 bolts I have torqued on the strong arm to the point I'm afraid something is going to break.
Are these things normally that hard to get off the taper? There is no sign of rust. Currently letting some penetrate oil seep in.
 

99yam40

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Re: replace all Yamaha carbs Chapter 2

I have hit the top of the puller bolt with a hammer while under the strain of being torqued to help jar it loose before , but I believe that is frowned upon, so wait for Rodbolt to chime back in.

Are you sure your connections are good
 

colayn

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Re: replace all Yamaha carbs Chapter 2

Got on here and learned this stuck flywheel is pretty common problem.
I really don't want to hit the puller (crank) I did try some heat with a propane torch, no luck.
Have my cheap puller on it now as tight as possible soaking over night with pentrate oil.

Removed the test wires and went into the coil wiring using piercing probes with the ohm meter and probed the conductors as far back as I can get to eliminate the connector and still circuit is open.
Low side looks to be close to the spec provided in an earlier post, high side open.
Surprised my manual (yamaha) doesn't have the spec in it. Not in any chapter I can find.
 

99yam40

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Re: replace all Yamaha carbs Chapter 2

I would think that if you have a Yamaha one it should give a spec sheet like don posted
 

seahorse5

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Re: replace all Yamaha carbs Chapter 2

My manual doesn't give resistance for the charge coils, I have looked everywhere. But going by the test sheets Don S posted earlier
Low should be 740 ohm and high should be 69
.

those specs are correct according to the Yamaha Tune-up spec handbook
 

colayn

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Re: replace all Yamaha carbs Chapter 2

Thanks Seahorse,
Going to try and rent a heavy duty puller today. Overnight soak and tension did not help. I have pretty much ruined my puller (cheap)

I keep thinking about the open in the coil circuit and wondering if there is some way I caused it. Really don't think so, but....
Of course I don't have the proper test harness , so I slide small wire along side the conductors into the back side of the connecter. In order to have more room
I did the low coil on one female connector and did the high coil on the male.
My test leads were solder to the wire, then I elec. taped just to be safe.
Even at 200v I don't think a arc could make the jump.
I don't see anyway I could have probed thru the connecter on the inside and shorted to leads.
Just looking at all the options.
What do you fellows think?
 

99yam40

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Re: replace all Yamaha carbs Chapter 2

Did you check resistance by disconnecting the connector and check from the inside of the connector?

You are looking for a open not a short, could be it the connector, wire, or coils. I am not sure if shorting the wires can burn out the coil.
Good luck getting the flywheel off. Maybe Rodbolt will give some advice.
 

colayn

Petty Officer 3rd Class
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Re: replace all Yamaha carbs Chapter 2

99yam40
yes the circuit is open. I have checked the connector (inside male pins) the way you mentioned and have probed into the wires between the connecter and the coil and still shows open.
Just have to get the flywheel off before I can go any farther.
Went today and rented heavy duty puller and bought some PB Blaster.
Lets see what happens
 

colayn

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Re: replace all Yamaha carbs Chapter 2

FINALLY got the flywheel off, after one broken puller, bolt heads popping off, alot of prayer a little heat and extreme tension.

The high coil has a hole blowed out from the result of a short.
I have looked and relooked and I don't think there is any way I caused this.
Really hoping this is the root cause of all my problems.

Retail price $410, I found one used for $97. Considering what I have learned that these Yammys don't have many electric problems would it be wise to proceed with buying the used one from this marine salvage yard ?
 

rodbolt

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Re: replace all Yamaha carbs Chapter 2

do ya feel lucky?
it may last the rest of the engines life, it may not.
goes for new as well as used.
 

colayn

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Re: replace all Yamaha carbs Chapter 2

I'm going to give the used one a try.
Rodbolt, If I had shorted my test leads would it have caused that coil to short and blow open?

I am curious, But I really don't think I did.

Will post after I get the parts and get all back together.
 

99yam40

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Re: replace all Yamaha carbs Chapter 2

All I know is that on electrical stuff they normally put overload devices in the circuit to keep them from burning themselves out in case of shorting. These things do not have that, but I have no idea if that is a normal possibility if outputs leads are shorted together with test leads
 

noelm

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Re: replace all Yamaha carbs Chapter 2

A coil output shorted out is no different to a bad spark plug, plugs short out all the time, and do not blow a hole in a coil or fry other components. Also another reminder to be careful when messing about, sometimes you may introduce another fault, and then you have two things to blindly sort out, this is not to say thats what has happened here, or people should not trouble shoot at home, but be aware of what you are doing.
 

colayn

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Re: replace all Yamaha carbs Chapter 2

Take off and went to the lake today after installing the salvage stator.
She ran like a scolded dog !!! Jumped up to 5800 RPM and all was smooth.

I can't thank you fellows enough for all the support.
A special thanks to Rodbolt and 99Yam40 , you guys stayed with it the whole , LONG time.

I truly appreciate what you did for me.
 

rodbolt

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Re: replace all Yamaha carbs Chapter 2

all ya needed was 1400 dollars worth of carbs.
your words not mine.
this should have ended over 100 posts ago.
like I say, just cause ya got some signs and a snap-on box, on payments, doesnt make you a tech.
this ENTIRE debacle should have been shut down in the FIRST hour of testing.
glad its done, for now.
 

throrope

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Jul 9, 2010
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Re: replace all Yamaha carbs Chapter 2

I just wandered across this thread.

I can't say enough about colayn's diligence and the patience and support of the friends he found here.

About half way through I suspected ignition, since the problem happens only at top end, but I had no idea a stator could be the culprit.

I'm not surprised at your conundrum with the dealer. Our new to us '04 ran like crap until I undid the service a marina provided. They slapped in parts, left off hoses and clips, missed an O ring, ignored sludge and then miss adjusted every screw and linkage. It took longer to find the problems they created than solving the difficulty.

Cudos to colayn for not breaking anything serious, especially the flywheel, and thanks for giving everyone the confidence to dig in for themselves.
 

rodbolt

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Re: replace all Yamaha carbs Chapter 2

half way?
dude I knew it when the first thread started about all THREE carbs failed and the hokey flow test.
I just could not get the owner to run all the tests quickly.
a trained tech with the correct test eqipment can run a full diagnostics on the entire engine in less than an hour on a 2.6L carbed V6 yamaha from about 1990 to present.
any more and something may be amiss.
a properly trained tech can do the carbs,fuel pumps and engine system in about 2 to 2.5 hours.
I got more time than that in about 120 posts on two different threads.
its also why the yamaha master tech exam is kinda tough.
it seperates the book worms from the field techs.
 
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