switchbox bench test

[izu]

I have an at idle intermittant misfiring condition that I am trying to troubleshoot. Fuel pump & carbs already rebuilt, on an 6cyl 115hp merc serial # 6480320. I took off the top switchbox and have a brand new one (from my 90hp merc: same part #)that I want to compare it with. Can I use a regular ohm meter or do I need a specific tester. I'd hate to put the new one on and have it get wiped out from some pre-existing condition Please advise !

 

[Laddies]

Re: switchbox bench test

There is no bench test for your switch boxes you have to test the system on the outboard with a DVA or a OHM meter, with some problems they will show up with a OHM meter but the DVA is by Far the best

 

[izu]

Re: switchbox bench test

OK Laddies I just ordered a DVA meter from ebay it should arrive in a few days,
I will respond when I get it

 

[izu]

Re: switchbox bench test

OK Laddies I got the DVA meter from ebay ! Whats my next move ?

 

[Laddies]

Re: switchbox bench test

Heres the test from CDI electronics

 

[ThumbPkr]

Re: switchbox bench test

Laddies,what does a DVA capable meter read that you need the DVA for?
What does DVA stand for?Thanks........Ron G

 

[JOHN12]

Re: switchbox bench test

Also, do u make the DVA test with it running or cranking?

JOHN12

 

[Laddies]

Re: switchbox bench test

A DVA is a direct voltage adapter and captures peak voltage, we use the term loosely as today there are many meters with that feature built in

 

[ThumbPkr]

Re: switchbox bench test

Thanks Laddies,you are a great resource here.Thanks for all that you do.Ron G

 

[Laddies]

Re: switchbox bench test

John running if it will and if it don't run pull the plugs install a spark gap on the plug wires and use the starter

 

[izu]

Re: switchbox bench test

Laddies I am confused, before we proceed let me back track a bit. Initially the problem occurred while out fishing (2 months ago) after running fine 1/2 the day I started the engine and pushed the throttle forward and could not get up on plane.
I thought it was running out of gas so I switched to a reserve tank. No luck a misfiring sound commenced and a loss of power condition, where even at full throttle it would not do over 2500 rpm. Since then I have rebuilt the carbs and the fuel pump ran deep creep through it and changed the plugs.

But it is still misfiring at idle. Please advise.

 

[izu]

Re: switchbox bench test

http://[URL=http://s182.photobucket...lbums/x210/izuizme/th_115hp-1.jpg[/IMG][/URL]I've made some progress. After a close inspection and comparison of the actual wiring to the wiring diagram in the clymer manual I discovered that the red wire from the idle stabilizer was connected to the top switchbox with the red/white wire from the stator instead were it should be,to the bottom switchbox with the red wire from the stator. I shot a brief video with sound and that misfiring sound has completly stopped. Check out the linkhttp://

 

[CharlieB]

Re: switchbox bench test

Not all motors used the idle stabilizer. Many have, in fact, been removed after becoming troublesome. If it now makes a difference, it is becoming troublesome. It is not absolutely necessary.

Use the DVA meter to test following the troubleshooting chart previously posted, CDI's system works to isolate your problem in a straightforward manner.

Wiggle triger wires while testing to check for broken/frayed wires.

 

[JustJason]

Re: switchbox bench test

A DVA is a direct voltage adapter and captures peak voltage, we use the term loosely as today there are many meters with that feature built in

just curious.... aside from the ES530 and the stevens dva "brick" peak meter.... what other meters have a dva built in?? i use my old fluke 8 and i have a fluke 88V as well. I also have a blue point dva adaptor and the cdi-rapair adapter (which both work fine with both fluke meters by the way). i was just curious as to which meters you meant because i only know the 2. (the ES530 and the stevens)

 

[izu]

Re: switchbox bench test

So as soon as I think it's time to put the boat back in the water for a test run something else comes up..I noticed a small ammont of oil dripping on the #1 cyl coil boot. So I remove the shroud and find a rubber tube that's almost severed.
I looked it up as part # 32 - 99387 79 It's a 22" bleed tube which at the top is connected to a check valve that screws into the engine block that's part # 21 - 42866. Now I am thinking that it's allowing air from outside the engine to "leak in" contributing to, or causing the misfiring condition.

 

[j_martin]

Re: switchbox bench test

Broken bleed tubes can cause idle mis-fires. I believe on that engine, they are pretty critical for bearing lubrication also. If it were mine, I would check all the tubes, and replace them if they seem to be deteriorated in any way. While you're there, test the check valves for proper operation. If you're not absolutely sure the bleed line routing is correct, check that also.

hope it helps
John

 

[izu]

Re: switchbox bench test

Thanks for your response John, I'll check that out tommrow and will post the results.
Compression Test
#1 130
#2 130
#3 110
#4 130
#5 130
#6 130

 

[ricksrster]

Re: switchbox bench test

just curious.... aside from the ES530 and the stevens dva "brick" peak meter.... what other meters have a dva built in?? i use my old fluke 8 and i have a fluke 88V as well. I also have a blue point dva adaptor and the cdi-rapair adapter (which both work fine with both fluke meters by the way). i was just curious as to which meters you meant because i only know the 2. (the ES530 and the stevens)

http://www.iboats.com/Multi_Meter_D...7251537--list_time.1192872047--view_id.271177

 

[AMD Rules]

Re: switchbox bench test

izu,

I'd suggest you remove the idle stabilizer, permanently. These motors are senstive to timing issues, and you're better off setting it manually and not hoping the stabilizer never malfunctions. More trouble than good.

Fix that bleed tube now, before proceeding. Its important, not only for pressure balance but as mentioned above it is part of the bearing lube circuit.

Sounds like you're making progress though. Good luck.

 

[j_martin]

Re: switchbox bench test

Just listened to your video. I'd be looking for wrong wired coils, or a broken magnet on the flywheel prematurely firing one cylinder. I sure wouldn't try to run it like that.

Disconnect the idle stabilizer until you have it running smoothly. You can then try hooking it back up if you wish. If it's bad, you'll know immediately, but it could help keep a cold motor running when you're trying to get away from the dock or trailer.

hope it helps
John