Yamaha 03 60hp Electrical issue

[Leftsinkhandle]

Hi All,

I've been trying to get my 03 60trlb to run right. The problem started with the engine not being able to build revs much past idle for the first 10-25 mins after being started then it would run great the rest of the day even if it was left off for several hours. I checked for spark while the problem was happening and found that their was no spark in hole 2, even with the motor running. I tested the following parts:

ignition coils; Tested for resistance
charge coil; tested for peak voltage (cranking open) and resistance
crank position sensor; tested for peak voltage (cranking open) and resistance
pulser coil; tested for peak voltage (cranking open) and resistance
CDI outputs (to igniton coils); Tested for peak voltage (cranking and running connected)

The only faults I found are the the crank position sensor reads 4.6~4.8 when it should read 5. And the CDI was not outputting any voltage to #2 even with the motor running. So I purchased and installed a new CDI. The motor ran great for 1 and 1/2 days then started randomly dropping off revs while running and reverting to its sputtering and only revving to just above idle and sometimes stalling out. It will occasionally run fine for a few seconds as if a switch was flipped but fall back to just sputtering and not building revs. I went back to testing ignition parts, testing the charge coil, pulser coil and crank position sensor with them connected while both cranking and running the engine.the only fault I found was the charge coil outputting ~20V peak while connected when it should be outputting 150V. And again the crank position sensor reading 4.6~4.8V. So I purchased and installed a new charge coil only to find that it still is only outputting ~20V peak while connected.

At this point I started looking for a short and monitored the peak voltage from the charge coil while cranking the engine and unplugging various things. I tried unplugging each component from the CDI unit 1 by 1 and testing the peak voltage at the charge coil only to see ~20v in all cases. I tried running the engine and unplugging ignition coils 1 by 1, still 20V. I tried unplugging the control wiring harness with the motor running, still ~20V. Finally I tested just the charge coil plugged into the CDI unit with nothing else connected to the CDI and Cranking it still only made ~20V.

In addition to all this electrical stuff I did a compression test (got 95, 95, 90). Changed both fuel filters. Cleaned the Carbs. Filled with fresh gas. rebuilt the fuel pump.


I'm at a complete loss for any ideas and very sick of throwing money at this POS. I am still convinced it is an electrical issue given the intermittent symptoms and the low output of the charge coil. Any help would be much appreciated (especially if you made it through my entire post). Thanks in advance!

[99yam40]

what kind of meter are you using to take these peak voltages with?

with a charge coil only putting our 20volts, none of the CDI outputs to the coils could be in spec and the coils could not create spark, so the motor cannot run at all

[Leftsinkhandle]

what kind of meter are you using to take these peak voltages with?

with a charge coil only putting our 20volts, none of the CDI outputs to the coils could be in spec and the coils could not create spark, so the motor cannot run at all

All the peak voltage readings were taken with this dva adapter (link) and a multi-meter set to DC. All of the other components test as expected using this method. And the charge coil tests at 150V while disconnected using this method.

[99yam40]

well it is good that you have the proper test equipment for peak voltages.
But how can the motor run if the charge coil is not putting out the needed voltage?

how are you getting to measure when hooked up?
do you have the test harness?

the kill switch will kill spark by grounding when the lanyard is pulled, are you sure that is OK

[panasonic]

Hello sir.

I have a suggestion you may consider. Wiring from the timing plate to the CDI is constantly being flexed with movement of the plate back and forth. Have you closely inspected these, both visually and with a meter while moving them around?
I am thinking maybe a broken wire inside the insulation from the description you have provided.

Also are you still losing spark on just #2 since you changed the CDI and charge coil?

[Leftsinkhandle]

well it is good that you have the proper test equipment for peak voltages.
But how can the motor run if the charge coil is not putting out the needed voltage?

how are you getting to measure when hooked up?
do you have the test harness?

the kill switch will kill spark by grounding when the lanyard is pulled, are you sure that is OK

Thats a good point about the charge coil. I agree if the charge coil was really putting out 20V their would be no way for me to see 150~160 at the CDI output. Maybe the pulse is just to short to charge the capacitor in my DVA. I think I might be chasing a ghost there.

I made a test harness with the plugs off the old CDI.

I checked the wire that grounds the CDI at the CDI with a multi-meter and couldn't find a route to ground. I might take her out tomorrow and do a water test with that wire disconnected to be absolutely sure.


Thanks for the replys!

[Leftsinkhandle]

Hello sir.

I have a suggestion you may consider. Wiring from the timing plate to the CDI is constantly being flexed with movement of the plate back and forth. Have you closely inspected these, both visually and with a meter while moving them around?
I am thinking maybe a broken wire inside the insulation from the description you have provided.

Also are you still losing spark on just #2 since you changed the CDI and charge coil?

I don't think that this outboard has a timing plate. The CDI has a throttle position sensor to do advance by throttle.

I had spark on number 2 whenever I checked but I am not confident that their is always spark given the intermittent nature of the problem.

Thanks for the reply, much appreciated!

[panasonic]

I don't think that this outboard has a timing plate. The CDI has a throttle position sensor to do advance by throttle.

I had spark on number 2 whenever I checked but I am not confident that their is always spark given the intermittent nature of the problem.

Thanks for the reply, much appreciated!

My mistake for not looking at the model number of your engine. But still think you have a bad wire/connection or ground that you have not found yet.

Strange the engine ran fine after changing out the CDI for a short while then started acting up again?? I would really look hard at the wiring to and from the CDI.

[Leftsinkhandle]

I ran the boat with the "kill wire" disconnected from the CDI this time it never ran properly at all. Ive checked every wire involved with the ignition system and cant find any faults. I guess the next step is to buy another outboard.

[99yam40]

I would monitor peak voltages on everything while running properly and then again when there is a problem and post all of those readings