1987 115ETLH Ignition

[classicmako]

Quick back story: '87 115 was on a boat that I restored over the last 3+ years. The first time out the motor wouldn't get over 3800RPMs or about 25kts. Cleaned out the carbs again (rebuild kit prior to launch) and reset the floats. While running the motor on the hose checking my work I had my hands resting on the heads. One was warm the other was cold Pulled the timing light out and noticed no fire on the port side.

Compression all with in 10% of 128#'s

Went through all the resistance checks with a Fluke 78 per cheapo Yamaha manual and got varying results.

White/Red Trigger-White/Yellow Trigger 362...they say 280-430
White/Black Trigger-White/Green Trigger 357...they say 280-430
White/Red Trigger-Eng Ground 1.37....they say open
White/Black Trigger-Eng Ground 1.61...they say open
White/Yellow Trigger-Eng Ground 1.37...they say open
White/Green Trigger-Eng Ground 1.67...They say open

Brown Stator-Red Stator 1.1...they say 840-1260 OHMS (BAD)
Brown Stator-Eng Ground 47.3...They say Open (Bad)
Blue Stator-Black/Red Stator 132...they say 65-130
Blue Stator-Eng Ground 1.3...they say open
Black/Red Stator-Eng Ground 1.3...they say open

I orderd a DVA should be here early this week...Testing without the DVA showed good voltage on the stator in the high 80's, but the triggers all around .8 and recommended low was 2.5.

Took the flywheel off for inspection and noticed some cracking in the plastic covering on the stator--not sure if thats a big no no.

Any help would be great---what readings should I get when my DVA comes in?

[rodbolt17]

84-89 pulser coil ohms should be 360 ohms 20% variable is ok.
84-89 low speed charge coil 1050 Ohms, same 20%
84-89 high speed charge coil should be 127 with the same 20% allowance.
these are all two wire coils.
from any lead to ground should show infinite resistance, open circuit.
ALL resistance checks MUST be done with the coils dissconnected.
let us know when your DVA gets in and ill give ya the specs for loaded,everything hooked up, and unloaded, dissconected.

[classicmako]

84-89 pulser coil ohms should be 360 ohms 20% variable is ok.
84-89 low speed charge coil 1050 Ohms, same 20%
84-89 high speed charge coil should be 127 with the same 20% allowance.
these are all two wire coils.
from any lead to ground should show infinite resistance, open circuit.
ALL resistance checks MUST be done with the coils dissconnected.
let us know when your DVA gets in and ill give ya the specs for loaded,everything hooked up, and unloaded, dissconected.

Can I still get an accurate diagnosis without a loaded test? I don't have a test wheel/tank...This would be on the hose up to 1500rpm.

Do cracks in the plastic insulation on the stator indicate an issue or just old age

[rodbolt17]

when we are disscussing voltage output tests loaded means the device is connected,unloaded means the device is not connected.
has nothing to do with engine load.

[classicmako]

So this is in regard to DVA connected/not connected. Perfect!

[rodbolt17]

no, DVA connected to the device being tested and the driven device dissconected.

[classicmako]

DVA will be in tomorrow - What type of readings are acceptable? Test the stator, pulser & rectifier. If all tests are good it's the CDI box?

Thanks guys!

[classicmako]

Measured with a Fluke 78 with a ES (electronic Specialties) DVA attatched in DC mode (DVA has a rectifier in it?)

Tests done at 1500 RPM

Brown-Red : 200v
Blue-Black/Red: 150v
White/Red-White/Yellow: 8.7v
White/Black-White/Green: 7.9v

Coils Out:
#1 cyl: 150
#2 cyl: 80
#3 cyl: 150
#4 cyl: 80

What do you guys think? Stator values seem high...

Now I need to do this cranking? Whats the procedure so I don't burn something up--including me

[rodbolt17]

stator values look good. high speed numbers are a bit high.
pulser values look good.
my bet will be on a bad CDI.
rare but it happens.
1&3 and 2&4 are triggered by the same pulsar coil.
same chargecoil input voltage on all 4.
the CDI does not reduce nor amplify stator charge coil input voltage.

[classicmako]

The stator had some cracks in the plastic. Anything I should worry about? Thanks Rodbolt--lets see what the CDI does.

[rodbolt17]

before you buy anything, can ya tell me what CDI stands for?

[classicmako]

I thought it was just a fancy capacitor ---Capacitor Discharge Ignition? Energy in stored and release via pulser coil.

[classicmako]

CDI fixed it! Try it out tomorrow...any problems and it turns into a reef and off to get an opti. To bad Yamaha doesn't make a 2-stroke...

Thanks guys!

[classicmako]

Ran great, but nipple on the motor mounted oil tank broke. Rigged it enough to get back to the dock and fixed it properly saving Mothers Day. Motor is being sold this week.

I like the Yamaha's and wish they built something for the older boats that wouldn't sink it, but off to american made motors.