Troubleshooting my XR4

[DamianJP]

I'm trying to troubleshoot these things on my XR4. Trigger , Stator , Switch Boxes , Coils.

I have a DVA and CDI's guide but can't start / crank the engine right now. So I was taking resistance test just to get an idea.

I took the resistances of the trigger and stator only yesterday. Trigger seems in spec , but the stator looks suspect abit. My rectifier did go out like almost a year ago and I ran the boat alittle with it bad. I put a new rectifier on but can me running the boat like that weaken the stator?

Stator resistance test

Say test should read
5400-6200 first 2 tests
125-175 last 2 tests


(Don't know if I have the stator stamped with 398-5454A34) Which calls out for 4450-4650 on first 2 tests
65-75 on last 2 tests.

Between blue and red 4.42K (4400)

Between blue/white and red/white 4.19 (4200)

Between red and ground 74

Between red/white and ground 74



Trigger resistance tests

All test were around or at 1300.

And all the tests, the manual calls out for 1100-1400 so I think the trigger is good.



I know I should do the CDI's guide while cranking/running because stuff can heat up and fail too and/or the testing reads better, but I just wanted to get an idea of what Im working with. What do you guys think of the tests?



Thanks,
DamianJP

 

[j_martin]

Re: Troubleshooting my XR4

My guess is your meter is off. It would be unusual for a bad one to be that even, sorta like all low but very even compression makes you check your compression gauge.

Why don't you try running some symptoms past us?

 

[DamianJP]

Re: Troubleshooting my XR4

Hey J

Well this happened once before. Running fine and then bam total power lose and rough sounding like it was slowly dieing. Try to re start with no warm up and nothing. Have to give it alot of warm up bar to try and get her going. And when I finally get her cranked over and feather the warm up bar to keep her alive, she sounds like crap. Like its not firing on all cylinders.

Last time this happened I let her sit along time, then try to crank her and she cranked fine like nothing ever happened. I was thinking that an electrical component was heating up and failing. It happened when I ran the engine for a good while.

What I really need to do is get her to warm up to the point of the same failure and check which cylinders is losing spark to get an idea if it's a whole bank going down or individual cylinders. That and to use my DVA with multimeter to get good tests.

I checked the engine, no idle stab. Just the high/low speed black box with Red-White / Black / White-Black wires. And the black box for the oil warning that the oil pump was attached to.

Both of my tests on the stator and trigger are both bad?


Thanks,
DamianJP

 

[j_martin]

Re: Troubleshooting my XR4

Hey J

Well this happened once before. Running fine and then bam total power lose and rough sounding like it was slowly dieing. Try to re start with no warm up and nothing. Have to give it alot of warm up bar to try and get her going. And when I finally get her cranked over and feather the warm up bar to keep her alive, she sounds like crap. Like its not firing on all cylinders.

Last time this happened I let her sit along time, then try to crank her and she cranked fine like nothing ever happened. I was thinking that an electrical component was heating up and failing. It happened when I ran the engine for a good while.

What I really need to do is get her to warm up to the point of the same failure and check which cylinders is losing spark to get an idea if it's a whole bank going down or individual cylinders. That and to use my DVA with multimeter to get good tests.

I checked the engine, no idle stab. Just the high/low speed black box with Red-White / Black / White-Black wires. And the black box for the oil warning that the oil pump was attached to.

Both of my tests on the stator and trigger are both bad?

That "high/low speed black box" on an XR4 is a combination Idle stabilizer and advance module. It could be the trouble, but not likely. It's not needed, but you need to reset the max advance if you remove it. Won't hurt if you don't, but you'll lose a little top end that you could have.

Don't know what you mean by "rough sounding" but this module when it fails tends to full advance the timing. (pins bias to ground)

If it were mine.....

I'd ditch the advance module.

I'd beg, borrow, or maybe even buy a couple of inductive timing lights, and put one on #1 plug, and one on #2 plug. Run it till it fails, and not if either one quits blinking. If neither quits, yer looking at a fuel problem, probably crap in the fuel pump or collapsing fuel line somewhere.

Actually I'd do the same thing by sampling the coil signal with my portable dual trace Tektronix oscilloscope, but I wouldn't expect you to buy one.

FYI, the theoretical operation of that module.
At low speed, if idle speed goes below 600 rpm, it advances the timing a few degrees.

At 5000 RPM, it advances the timing from the preset 19? to 23?. At 5500 rpm, it retards the timing to 17?.

I found that when I removed mine and retimed Max Timing to 23?, I could turn a slightly steeper prop to 6000 rpm.

hope it helps
John

 

[DamianJP]

Re: Troubleshooting my XR4

Cool J thank you

Iv'e got 1 timing light so far. Mabey Ill snag another cheap one at harbor freight.

Just did the carbs and fuel pump rebuild before this happened. Also the tank sat with gas in it for 10 months but I drained it and replace the water separator to eat up what ever 'little' bit was left in there.

Ill check for collapsed lines too.

By rough I mean, its not firing on all cylinders " I think". Have to hit it hard with the warm up bar to push the dead cylinders it sounds like, but not sure. I gotta recreate the symptoms and troubleshoot.

I also picked up two 90 degree inline spark checkers at harbor freight the other day. Can I use those to check the spark instead of the lights? At $3 I couldn't pass em up. Might just grab 4 more so I can check the spark on all cylinders at one time to really watch whats failing when it does.


Thanks again man,
DamianJP

 

[CharlieB]

Re: Troubleshooting my XR4

Cranking spark tests are MANDATORY to troubleshooting!

Ohm's test may seem reassuring when the numbers fall within range,

HOWEVER, If the ignition fails to provide a bright blue 7/16 spark on ALL cyls, the motor will not perform well.

 

[DamianJP]

Re: Troubleshooting my XR4

Hey J

I seen a post by you saying this...

"The beeping could be ignition failure as the oil alert module gets one of its signals from the coil drive (usually #2) Intermittent failures are hard to find, but i'd first disconnect the kill wires and measure from either wire to ground with a good ohmmeter. It should be infinity unless the ignition switch is off or the engine is tilted up. If anything else, troubleshoot the short/leakage."


That got me thinking, Iv'e had that Beep beep beep and when I heard that I took off my oil pump and pre mixed because I thought it was the oil gear slipping. When I converted to pre mix the damn beep beep beep would show up from time to time and I was left scratching my head. Could that be a clue that some were my spark signals is screwy since the oil pump is not there and the beep beep beep still happens from time to time?


Thanks,
DamianJP

 

[j_martin]

Re: Troubleshooting my XR4

Hey J

I seen a post by you saying this...

"The beeping could be ignition failure as the oil alert module gets one of its signals from the coil drive (usually #2) Intermittent failures are hard to find, but i'd first disconnect the kill wires and measure from either wire to ground with a good ohmmeter. It should be infinity unless the ignition switch is off or the engine is tilted up. If anything else, troubleshoot the short/leakage."


That got me thinking, Iv'e had that Beep beep beep and when I heard that I took off my oil pump and pre mixed because I thought it was the oil gear slipping. When I converted to pre mix the damn beep beep beep would show up from time to time and I was left scratching my head. Could that be a clue that some were my spark signals is screwy since the oil pump is not there and the beep beep beep still happens from time to time?


Thanks,
DamianJP

If you have not removed the oil-alert module and you removed the oil pump, it should be beeping incessantly whenever the engine is running. The beep beep I was discussing was from the oil alert module.

 

[DamianJP]

Re: Troubleshooting my XR4

Wierd

It only beeps here and there. Not all the time. So go ahead and remove it completely?


Thanks,
DamianJP

 

[j_martin]

Re: Troubleshooting my XR4

On that engine, the only thing the oil alert module checks is the oil system. If you don't have an oil system, why have the module?

On an EFI engine, the water switch is wired into the oil alert.