1988 125hp idle rpms?

[yfz450guy]

i have a 1988 125hp and have been having an issue with power loss the motor feels as if it has a govener on it at wot. i have spark on all 4 and the comp is within spec. i heard from a guy to check the key switch so i did and it failed the final test in the manual. so i replaced it it ran better than it has for a few weeks. so i think cool $20 fix to a 3 week headache. ran around the lake with the wife and dogs dropped them of at camp and headed out to do some fishing boat ran great. got to the other end of the lake fished for a few hours and went to move to another spot and it ran crappy again. limped back to the dock and completely bypassed the switch. still crappy. loaded up and drank beer the rest of the weekend.
changed the primer bulb, filter, checked plugand 1and 2 are oilyish and 3 and 4 are a little too clean for a 2 stroke i think. checked screen in the pump and it was clean. pulled the carbs today and they too were clean as new and needle seats and floats looked good too. i made sure the carbs were linked and synced fired it in the tank and still crap. so i changed out the voltage reg and put the rectifier back in and while it sounds like it is running better my rpms per cyl are differnt and i can't understand why.
i have a meter that has tach and dwell and an rpm clamp. i put it on 1 and 2 and the rpms pretty much match the tach on the dash. i put it 3 and 4 and the rpms are 1000 to 1500 rpms less. would that mean a timing issue?
i am lost here. almost tempted to throw another key switch at it and see what happens. if i did and that made it better then what is causing the key switches to burn out?
thanks in advance for any and all insight on this.

 

[pnwboat]

Re: 1988 125hp idle rpms?

I would suspect that you have weak spark on 3 and 4. You know that the motor is turning the RPM's indicated on the tach. Possible cause for the difference in readings is that the spark on 3 and 4 is not strong enough to trigger the pick up on your meter. Clean plugs also indicate no combustion taking place. Also caused by insufficient spark to ignite fuel/oil mixture. Need to OHM out stator, trigger and coils. If they are within spec's. I would suspect the CD module. You can swap the CD modules around to verify. If problem moves, then that would confirm the CD module is bad.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

i swapped the packs arounfd before the key switch was replaced and did not notice a differnce. i have been working at this for as i stated 3 weeks and have ohm'd the coils, trigger, stator and as per my tests they all checked out within spec that is why i put the switch in as i had nothing but 20 bucks to throw a way. the key test that was failed was the voltage drop test. the book say's if the voltage drops more than 1 volt then the switch needs to be replaced. i tested the old one beore i got the new one and the voltage dropped from just over 12 volts to the high 8's. so i went and got a new one and put it in and i tested it and it went from 12ish to high 10's. but ran it anyway and it made a differnce.
could the wiring harness from the motor to the dash be bad and causing too much resistance?
i know that when i restored the boat a couple years ago i had to cut and splice quite a few wires to get to clean wire. thinking also about cutting new wires and putting the switch right at the terminal block by the starter. that should remove the entire boat from the equation. what do you think about that?

 

[pnwboat]

Re: 1988 125hp idle rpms?

The voltage drop test is for the electrical system that runs the accessories and starter. The ignition system is completely separate from this. Voltage for the ignition system is generated by the magnets in the flywheel and stator. The motor will run without being connected to the battery or electrical system (once you get it started).

Sounds like you have Ohm'ed out the coils but have you moved the coils around? Double check the ground connection on each coil, and the ground wire that goes from the coil mounting plate to the block. I added an additional wire to make sure I have a good ground

If I were a betting man, I'd say you have an ignition system problem. Something is not right with cylinders 3 and 4. Double check the spade lug connections on the 12 position terminal block. I've had the wire break, but I couldn't see it because the break was inside the black heat shrink covering the wire where it's connected to the spade lug. Very tricky because the heat shrink holds the spade lug to the wire giving you the impression that the wire is OK. I ended up replacing all the spade lug connectors on the wires. Cured my intermittent ignition problems. I had a trigger connection that was hanging on with one strand of wire. Ohm'ed out OK, but I guess when under operating conditions, it was not good enough to trigger the CD module.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

i have been reading posts here for the last three weeks and have seen you post that info on the connectors. i have pushed and pulled on all the spades while the engine is running no differnce. when i say pushed and pulled i mean it. thought if it was weak then it will break off the rest of the way.
so if the mags in the flywheel were broke and some how shifted that would cause the timming for those cyl to be off would it not?
also the 2 plugs on the cdi's that plug into the coils are not looking to good and i was thinking about cutting them and using regular bullet connectors, what do you think about that? maybe crimp and solder? i have 3 other coils and 1 cd box and a stator from a 3cyl i picked up for parts. i ohm'd them and they appear to be good. maybe i should yank (really hard) the fly wheel off and everything out under there?

 

[pnwboat]

Re: 1988 125hp idle rpms?

Timing magnets that trigger 1st and 2nd cylinder are the same ones used to trigger 3 and 4. Doubt you have a timing issue. I don't think you need to take the flywheel off. You might look at the wires that come out from the flywheel to see if they've rubbed the insulation off somewhere. Have someone move the throttle and watch the wires as the trigger assy under the flywheel moves. The wires from the trigger sometimes get bound up.

Any connection that you suspect is bad I would correct. Soldering the coil connections will eliminate that, but it will make it more difficult to replace. I would shy away from soldering those connections, but that's just my personal preference.

Sounds like your problem is somewhat intermittent? Sometimes motor runs OK? These types of problems are the most troublesome to diagnose.

I would use the CD Module that you picked up (hopefully it's good) and use it to troubleshoot. Replace the CD Module for cylinders 3 and 4 first. If that doesn't fix it, put everything back to the way it was, and then replace CD Module for cylinders 1 and 2. If the blocking diode in the kill circuit in the CD module for Cylinders 1 and 2 is bad, it can affect the other CD module.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

i have swapped them out. i took out the box for 1 and 2 and replaced it with my spare from the parts motor. that was the one that was bad last year. no diff. so took the box i took out and put it on 3 and 4 since as far as i know that is still the original box and no diff. what i will do tonight after work is take the box from 1/2 and move it to 3/4 and 3/4 to 1/2 and see what that does. it may be that the original box went bad and the spare is bad also?
as for soldering the coils, what was meaning was to replace the factory plugs with bullet connectors and not only crimp the connectors but solder them to boot to besure of a good and solid connection as opossed to just the crimp. though i did consider just strait solder.
i do have a spare stator and trigger but the trigger won't work since it is from a 3 cyl. i wish i had a way to load test the stator. the guy it got the parts motor from said that he thought the stator was bad.

 

[john from md]

Re: 1988 125hp idle rpms?

Are you still using the OEM ground setup for the coils? If so, take a couple of jumpers and jumper the suspect coils to a good ground. See what happens.

Outboards tend to get high resistence grounds after a few years of use just from being in humid environments. Salt water use compounds the issue.

If you still have weak spark, I would suspect the charge coil portion of the stator as the coil output voltage is proportional to input voltage.

John

 

[pnwboat]

Re: 1988 125hp idle rpms?

Yes I would suspect something out of the ordinary is going on with your motor. Swapping the CD modules around is a start. Keep in mind a CD Module that is firing the coils properly may in fact be bad and preventing the other good CD Module from firing properly. That's why I suggested replacing them rather than swapping them. Six of one, half a dozen of the other. Just personal preference on how you want to go about trouble-shooting.

I suggest that before you do anything,...... fire the motor up in a tub or muffs, pull one spark plug wire off at a time and see if it affects the idle. Make a note which wires do not affect idle. If no change in idle, this indicates that cylinder is not firing properly. Do your swapping or replacing and do the spark plug wire test to see if any difference.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

well i did an output voltage test on the stator wire for 3/4 and if i did it right i get within spec voltage at idle but as soon as i up the throttle i lose voltage but it comes and goes but mostly goes. stator?
i have an extra stator how do i bench test it before going to the trouble of installing it?

 

[pnwboat]

Re: 1988 125hp idle rpms?

Sounds like may have found the problem. I don't know of a way to bench test it before installing. Only way that I know of is to Ohm it out and visually check it for signs of overheating, burnt spots etc. Did you use a DVA meter or a DVA adapter with a standard meter? If not, you will get unreliable readings depending on what model meter being used.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

i have a cornwell tools automotive type that does ac dc ohm rpm tach dwell. is selectable upto 8cyl. 2 and 4 stroke. and may do more that i don't know about. i had the engine running rough but running at about 1500 2000 rpms when i did the test. if i slowed the ,otor the voltage came back and went up into the mid 200's i saw 300 once or twice. but when i gave it more gas the voltage went away but would flash so to speak once in awhile. guess i should have checked the 1/2 leads to comfirm numbers but i didn't.
i brought my puller kit home and figured i would just change the stator out with the one i have but forgot my 1/2 drive impact and do not have a 3/8 drive socket big enough.
i looked up the meter on the web here is what cornwell says about it.
The Basics


Part Number OWC3514


Description Automotive Meter


Catalog Page 2008-149
Specifications





Other Characteristics


The Details


? Accurate ms-pulse width function to test on-time for fuel injectors, IAC motors and transmission controls. ? Inductive rpm for 1-8 cylinders (2- or 4-stroke), inductive clamp included in the kit. ? Direct dwell readings and duty cycle. DC volts and mV, AC volts, ohms, continuity, frequency. ? Four step adjustable ? trigger. ? 4-1/4 digit display. Analog bar graph, 41 segment. ? Auto ranging, automatic power off and data hold features. ? 10 MEGOHM impedance protects automotive computers circuitry. ? Rugged construction for years of use under the harsh automotive shop conditions. ? Weight: 1 lb., 9 oz. ? Includes analog/digital multimeter, protection holster with stand, safety-designed test lead set, inductive pickup, 9V battery (installed) and user?s manual.

What?s in the Box?


Multimeter, Low Amps Probe, High Amps Probe, RPM Pickup, Test Leads, Set of Test Prods, Set of Clips, Manual, Storage Case
Top Features


Accurate ms-pulse width function to test on-time for fuel injectors, IAC motors and transmission controls.


Inductive rpm for 1-8 cylinders (2- or 4-stroke), inductive clamp included in the kit.
Certifications & Qualifications


CE Certified
Application Notes


Low Amps range can be jumpy in noisy


is this the right kind of meter?

 

[yfz450guy]

Re: 1988 125hp idle rpms?

ohm'd the extra stator on the bench and the number 1 wire shows continuity to the inner ring and the 1 and 2 wires show intermintent cont.

 

[john from md]

Re: 1988 125hp idle rpms?

yfz450guy,

I believe you need a DVA adapter for your meter in order to properly check output voltage from the stator, CDI module and coils. Check your manual and see what it says. If required, measurements using a meter without the adapter are not reliable.

There is a company on the net that sells adapters for $30 but I am not at home so I can't give you their url.

John

 

[pnwboat]

Re: 1988 125hp idle rpms?

I couldn't tell you if the meter you used is the correct one. Like you mentioned, check the stator voltage for 1 and 2 and compare readings. If 1 and 2 read the same as 3 and 4, then I would tend to think that the meter you're using is not reading correctly. If the stator windings Ohm out OK, chances are that it is probably OK, although there is a chance it may be failing under a load/heat.

I guess you're at a point where you need to make a decision. Do I take the flywheel off and look at the stator?....Or do I start swapping/replacing the CD Modules. Comparing readings with your meter between the stator leads between 1 & 2 and 3 & 4 may help. If they are the same I would look at the CD Modules. If different, then pull the flywheel. Personal preference at this point as to which direction you want to go.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

i re ohm'd the stator and the #3 lead is showing continuity to the power head. is that bad? it is the only one of the 4 leads that does it.

 

[pnwboat]

Re: 1988 125hp idle rpms?

None of the leads should show continuity to the block. Did you disconnect the wires from the terminal block or were they still connected? If they were connected, try disconnecting them and checking again.

 

[yfz450guy]

Re: 1988 125hp idle rpms?

they were all disconnected from the terminal strip.
i went ahead and pulled the fly wheel and can see no visable damage but there is a lot of surface rust on the stator and the trigger is kinda dirty/rusty around the inner ring. can i use steel wool or emery paper to clean it up trying not to remove too much of the metal? i figured i would clean the inside of the fly wheel with some brake cleaner.

 

[pnwboat]

Re: 1988 125hp idle rpms?

Spray the inner metal ring with some WD-40 then steel wool or fine emery. Stay away from the windings themselves. Once you're finished, take the brake clean and spray it all off.

Sounds like the #3 winding has shorted to one of the coils that it's wound around. Once your finished, Ohm it out again and see if it still shows bad. Wiggle the wires etc to see if you have an intermittent short. Never know, you might get lucky and be able to fix it.

 

[yfz450guy]

Re: 1988 125hp idle rpms? "update"

Re: 1988 125hp idle rpms? "update"

ok, i replaced the stator as it tested bad but that did not fix the entire problem.

been at the lake since friday and home today to p/u the ol'lady and dogs and heading back up. anyway.

spent all the time at the lake working and trying to figure it out. ran motor from second fuel source and not change. swapped out the cd boxes no change. put new plugs and she ran great. for half the day. changed the plugs again and she ran great. half the day.

i told you that story to get to this one.

got out on the lake and got the motor wot, strapped the steering wheel (do not try this at home, i am a paid proffesional) only going about 3500 rpms.
cover was aready off the motor and i with (3 layers of latex gloves on so not to get zapped) started wigglin' wires and when i got to the plastic connectors for the coils she about threw me out the back of the boat i tell ya.
so i did what i knew i should have done when i thought of it.:redface: i limped back to the dock and proceeded to pull the electronics plate and cut the 4 conectors off and crimped on new conectors. was going to shrink tube but taped instead as to aid in replacement someday. took her back out and she ran great.
so it is my opinion that if the coil conectors look the least bit iffie then replace them!