Yamaha 150 TXRC: Help Understanding DC Voltage readings

[99yam40]

I would be looking at your meter too, to make sure it is reading correctly
seems even the ohms are off by about a factor of 10 on the charge coils
74 instead of 740
7.6 instead of 69

remember the manuals give minimum peak voltage specs, they can be higher

[Psalm 99]

Sure nice to see some light at the end of the tunnel! Find out after tomorrow's testing but it seems I'm on the right track.

[Psalm 99]

Took bad resistance readings as a busy day on the farm was winding down, only excuse I've got. Now using two digital meters and an older dial meter. All are giving same resistance values for pulse, charging coils and CPS.

[99yam40]

Well if 3 meters agree the reading should be correct.
I said should.

where is the farm?
I am seeing lots of plowed ground down here along the TX coast and heading up towards the TX hill country here lately

[Psalm 99]

Farm is on the east (rainy) side of the Big Island (Hawaii). Miles and miles of just green grass and relatively few people. Much different than the 'resort Hawaii' that most people envision.

[Psalm 99]

Winky-blink and DVA arrived. Started with Winky-blink: With engine at approx. 1600 rpm, got a '33' code for about 2 minutes, then engine gave sort of a hiccup or 'blurp' and thereafter gave a normal '1' code at both idle and up to 2800 rpm. DVA on discharge side of CDI (voltage to coils) gave 200 VDC on both sides (good spark). Shut down engine and re-started but normal '1' code remained. This pretty much agrees with what's happening at sea as problem is intermittent. Manual states that if Winky-blink gives a '33' code, then replace the CDI unit. The '33' code is a little confusing as it apparently simply indicates that 'Ignition timing is being slightly corrected (when starting a cold engine)'. Seems like you'd want this to happen but the manual says if you get this code, replace the CDI. Definitely somethings wrong as the engine jumped when the CDi code went from '33' to normal '1'. Been running the engine on muffs for years and never had that happen.

[panasonic]

I myself would be looking at the wiring and connectors very carefully before shelling out for a new CDI.

Perhaps wiggling all the connections on the harness while the engine is running properly and see if you can get it to fault in the same manner.

[rodbolt17]

code 33 is normal and will remain until the engine reaches about 113*F then if all is well the ign timing reverts to ECU con*****ed the RPM's drop and code 1 appears.I would check the DVA output from the CDI at the time of an issue.
remember you have 2 2 wire pulsers triggering 4 ign coils and a CPS signal the ECU uses to make two more triggers.
the charge coils actually generate the current for all 6.

[99yam40]

did you check the out puts of the charge coils to the CDI?

seems you had your problems at the higher RPMs not Idle
So I thought you were looking at the high speed charge coil

[Psalm 99]

Problem definitely is sporadic. Ran engine at varying rpms with multiple starts. Three times out of about six I got a code '13' on the winky-blink indicating a problem with the pulser coil. All times it happened with the across W/R-WG @ the pulser coil input to the CDI. Engine often will revert to a code '1' indicating 'normal'. Pulser coil output to each side was a strong 15 vdc using DVA. Output from the CDI to each of six ignition coils is a strong 200 VDC.

[99yam40]

OTE=Psalm 99;n202232]Really want to thank you guys for all the helpful information. A DVA and winky-blink get here Saturday and with the proper eq[QUuipment, I should be able to isolate the problem. Leaning toward the charge coils at this point as the resistance readings from both coils are only about 10% of design. I'll go through the entire coil and CDI procedures regardless. Hopefully, about 3.5 years of intermittent frustration will end soon.[/QUOTE]

so you have not checked all of the coils yet

[Psalm 99]

My initial recordings on the coil resistance were wrong. All coils (pulser & charge) were right up to spec on all legs. Sorry for the mistake. At this point, only the intermittent '13' signal from the winky-blink appears to be the only problem that the work has uncovered. Hopefully, this is the cause of the problem. My last post should have stated that the intermittent '13' code from the winky-blink happened as I had the DVA set up to take peak voltage readings from the pulser coil connection to the CDI. I simply have a beveled paper clip inserted into two proper leads to get peak voltage (loaded). Resistance of course was taken with the leads uncoupled from the CDI.

[99yam40]

But you still did not say what the 2 charge coil peak voltages were.
Just wanted to know if you tested them.

I am guessing you did since you say pulsers and charge coils are up to spec, but am not sure it that was for ohms or peak voltage

[rodbolt17]

code 13 indicates something about one of the two pulser coils are not feeding information to the ECU/cdi.
lose one leg of a pulser and you lose one cyl,lose both legs on a pulser you lose spark on 4 cyl.
it is a simple system but I never understood why two pulsers and a CPS.

[99yam40]

seems like the testing needs to be done while the problem shows up to see what is causing the reduction in RPM