Switch box question

[hdman97]

How do these typically go bad?
I have done some searches here and it seems most problems are no spark at all.
I have an older 45hp clasic 50 (1989) this motor has few hours on it.
It wasn't used for several years.I replaced the impeller,mixed fresh gas in a new fuel tank put on the muffs and fired it up ran it for several mins fine.
Took it to the lake started right up ran wot for about 3 mins and then it started to bog down sometimes returning to wot.
Got it home checked for spark found ok all 4 cyls.
My question.... is my problem with the switch box? How can I test this?
Sounds like it is not running on all cyls, problem comes and goes.
Thanks .............

Rick

 

[achris]

Re: Switch box question

How do these typically go bad?
I have done some searches here and it seems most problems are no spark at all.
I have an older 45hp clasic 50 (1989) this motor has few hours on it.
[size=+1]It wasn't used for several years.[/size]I replaced the impeller,mixed fresh gas in a new fuel tank put on the muffs and fired it up ran it for several mins fine.
Took it to the lake started right up ran wot for about 3 mins and then it started to bog down sometimes returning to wot.
Got it home checked for spark found ok all 4 cyls.
My question.... is my problem with the switch box? How can I test this?
Sounds like it is not running on all cyls, problem comes and goes.
Thanks .............

Rick

Rick,

That's the clue... I'd be looking at pulling the carbs, fuel pump and all the fuel lines and cleaning them out before I look at the ignition system. If you have all 4 sparks good and strong, it's not the switchbox... Go carby cleaning...

Chris........

 

[hdman97]

Re: Switch box question

Chris,
Well I also thought it should be fuel related,but it sure seems more like
a spark problem.Sure won't hurt to clean up the carbs etc.
Just wish I knew how those switch boxs go bad.

 

[Dave1027]

Re: Switch box question

I think the only way to check it is to swap it and test on the water. See if you can borrow one from a mechanic.

 

[achris]

Re: Switch box question

Chris,
Well I also thought it should be fuel related,but it sure seems more like
a spark problem.Sure won't hurt to clean up the carbs etc.
Just wish I knew how those switch boxs go bad.

Mostly they just fail completely. They rarely go intermittent. It could be the mercury switch, try disconnecting it.

To test the switchbox you need a DVA. Either buy one or make an adaptor for an existing meter. Click HERE for instructions on building an adapter....

Chris...........

 

[hdman97]

Re: Switch box question

Mostly they just fail completely. They rarely go intermittent. It could be the mercury switch, try disconnecting it.


I dont think I have a mercury switch on this model or do I?
Thanks Chris for the plans for the adaptor,beats buying the DVA

 

[Dave1027]

Re: Switch box question

To test the switchbox you need a DVA. Either buy one or make an adaptor for an existing meter.

Nice but how do you use it. I'm familiar with electronics. I'm thinking you must have the engine cranking to do it.

 

[achris]

Re: Switch box question

Nice but how do you use it. I'm familiar with electronics. I'm thinking you must have the engine cranking to do it.

Errr, you think???

If you are familiar with electronics then you would know that in order for a magnet to induce current in a wire it needs to be moving.... You figure out the rest.

Chris..........

 

[j_martin]

Re: Switch box question

Nice but how do you use it. I'm familiar with electronics. I'm thinking you must have the engine cranking to do it.

I'd quit guessing and get a maintenance manual.

 

[Dave1027]

Re: Switch box question

I'd quit guessing and get a maintenance manual.

I have the factory service manual. Freaky thing is that use of the meter with DVA is not covered in it. It goes into doing a resistance test of stator, trigger and coils but that's it.

It seems I touched on some sort of sore point with you guys. I really only asked how to use the meter/DVA out of curiosity. I have no need to know right now. Sheesh! You'd think I was asking for personal info the way you guys bit my head off for bringing it up. Excuse me for asking

 

[achris]

Re: Switch box question

I have the factory service manual. Freaky thing is that use of the meter with DVA is not covered in it. It goes into doing a resistance test of stator, trigger and coils but that's it....

I was curious about your comments, so I picked a service manual at random (i chose the 30/40 4 cylinder engines) and looked in the ignition section. It's all there in very simple terms, exactly how to check all the ignition voltages, even using phases like "Set the meter switch to the 400DVA position. Crank the engine and observe the meter reading." Then it goes on to tell you the expected result and what to do if the result is not in the expected range....

You are the second person today who has asked for help on something that could be researched by yourself. I have made over 6,500 posts here helping people with real problems. When someone asks for something so basic and so easily found, yes, I can get a bit snippy.

C............

 

[Dave1027]

Re: Switch box question

achris,

I double checked. My manual does not have the procedure. I have manual 90-13645--1 1-389. It's from Brunswick (1989) and it covers Mercs and Mariners, 3 and 4 cylinder models 70hp thru 115hp.

I looked in my notes and I do have the procedure on copies that it looks like I made from the library of a Chiltons manual maybe.

 

[hdman97]

Re: Switch box question

Well I went thru all fuel related ,lines fuel pump and carbs.
Clean up the carbs which looked fine.
Guess I'll have to get the parts for a dva adaptor and check the stator,trigger
and coils.
Im sure the problem will be in the most expensive part,my guess is the switch box.
Looks like CDI is my best bet,do you guys agree?

 

[achris]

Re: Switch box question

achris,

I double checked. My manual does not have the procedure. I have manual 90-13645--1 1-389. It's from Brunswick (1989) and it covers Mercs and Mariners, 3 and 4 cylinder models 70hp thru 115hp.

I looked in my notes and I do have the procedure on copies that it looks like I made from the library of a Chiltons manual maybe.

Try Section 2A, page 1... under "Test Procedures, DVA"

If it's not in your manual, someone has ripped it out. Download a new (pdf) copy HERE.... (Password for the file is <ribforum>)

Chris........

 

[achris]

Re: Switch box question

Well I went thru all fuel related ,lines fuel pump and carbs.
Clean up the carbs which looked fine.
Guess I'll have to get the parts for a dva adaptor and check the stator,trigger
and coils.
Im sure the problem will be in the most expensive part,my guess is the switch box.
Looks like CDI is my best bet,do you guys agree?

CDI, yes.... Just double check all the ground wires a clean and tight....

 

[hdman97]

Re: Switch box question

Try Section 2A, page 1... under "Test Procedures, DVA"

If it's not in your manual, someone has ripped it out. Download a new (pdf) copy HERE.... (Password for the file is <ribforum>)

Chris........

Chris
Is there a pdf manual for the 45 hp clasic 50 1989 at rapidshare also?
The test procedures seem clearer than the ones I have in my manual.
Thanks......

Rick

 

[zorak]

Re: Switch box question

I went with CDI's test procedures ( from their website) as they were freely available and easy to follow. I had a manual i downloaded that was for a newer engine but according to it my stator was questionable. The stator,trigger and coils tested well within the specs listed on the CDI website and i was able to eliminate everything but the switchbox which was bad as it turned out.Just another option for you to follow as Chris is very knowledgeable and wouldn't steer you wrong.

 

[Dave1027]

Re: Switch box question

Try Section 2A, page 1... under "Test Procedures, DVA"

If it's not in your manual, someone has ripped it out. Download a new (pdf) copy HERE.... (Password for the file is <ribforum>)

Chris........

Thanks Chris,

It's weird. My manual is not missing any pages but it is missing the "Test Procedures, DVA" section. I don't know why.

 

[achris]

Re: Switch box question

Chris
Is there a pdf manual for the 45 hp clasic 50 1989 at rapidshare also?
The test procedures seem clearer than the ones I have in my manual.
Thanks......

Rick

Unfortunately not. But THIS manual is pretty close for most things. It's the same basic block and gearbox. It also covers many of the trim systems used, so I suspect yours will be in there. (Password for the fie is <ribforum>).

Chris.......

 

[j_martin]

Re: Switch box question

Have you bothered to check compression?