Summary of my issues (1990 50 hp Johnson)

[22E6441]

For two months I've been going crazy trying to get my boat fixed. This started back at the end of May, when my boat started sputtering or misfiring under load. I could not get the boat to go more than quarter throttle.

http://forums.iboats.com/showthread.php?t=315581

It was suggested that I got some junk in my carbs, so I picked up and installed some carb kits. Here are all of my pictures from the rebuild:

http://forums.iboats.com/showthread.php?t=338495

Before I actually got it running again, I blew a fuse a couple times. It's the red inline fuse under the electrical cover. There is a picture of it in the next linked thread. I figured I was blowing it because I didn't open the primer to help prime the carbs. I did so, then it worked great. Took it out and had the same problem again.

http://forums.iboats.com/showthread.php?t=325736

It was suggested that I do a link and sync. I figured that the procedure was a bit beyond me, and I don't have the tools anyway (like a good timing gun). So I took it to the shop and had a bit of work done.

http://forums.iboats.com/showthread.php?t=332959

I'll post some important comments from the other thread here for convenience:

Comments from mechanic:

Carbs look good
Set up idle mixture screws and throttle plate
not coming up to temp
found loose seat and old seat from thermostat still in motor
removed old seat and installed other seat properly
shifting and cooling ok
idle and throttle advance ok
motor starts and runs well

Also made a note that my temp alarm isn't working. he said that the temp alarm is separate from the vro oil alarm. I thought the temp alarm didn't work becasue the oil side of my vro was disconnected and I thought the alarms were all connected

.

As noted in that thread, I took the boat back to the shop but the mechanic was off. Another person there suggested that it might be something like bad o-ring in my tank or line. I had an old steel tank and old gas line from the tank to the motor, so I figured what the heck and replaced them both.

I took it out for a test run (a short run due to lousy weather) and it seemed to be OK.

Took it out again the other day when the weather finally turned nice....no love. This led to a series of posts, starting with:

http://forums.iboats.com/showthread.php?t=340321

Then trying to figure out what SLOW is, and if that has something to do with my engine.

http://forums.iboats.com/showthread.php?t=340435
http://forums.iboats.com/showthread.php?t=340431

So, this is where I'm at now.

Had the boat out today. Started perfectly. Idled perfectly. Left the channel no wake speed perfectly. Started to apply throttle...BINGO! Got on plane quick and easy...seemed perfect....then BLAMMO. Chug chug sputter sputter misfire. Back off the throttle and it runs perfect again.

Like I mentioned in a different thread, I disconnected the wire to the temp switch, it made no difference.

I tried the boat a few times, always waiting about ten minutes between tries and disconnecting my negative battery terminal before starting again. Same thing kept happening.....up to 1/4 throttle and "chug sputter misfire" herein after referred to as CSM (Chug Sputter Misfire).

Some observations:

1. The engine does not seem overly hot. I can easily put my finger on the block for a 1-2-3 count.
2. The thermostat housing seemed hotter than other parts of the motor, but not much.
3. The engine is peeing strong. This to me means good water pump and impeller, because if one of the two were not working well the stream would not be as strong as it is.
4. The temp of the stream is fairly cool, but feels a bit warmer intermittently at idle after it starts doing the CSM. Again, the shop said it was coming up to temp and working properly.
5. There does seem to be some blow back out of my carbs evidenced by some gas seeping out of a hole on my air silencer, but I don't know how much.

So, with the rebuilt carbs, new lines and new tank, I'm relatively certain that it is not a fuel problem. Also, pumping the bulb makes no difference.

It's not the temp switch, since disconnecting it made no difference.

The motor ran well in the shops test tank with the test prop wheel thing. This is an authorized and reputable shop / dealer.

I only wonder if maybe they didn't run it for long enough in the tank for it to start acting up.

Again, when I took it out today it seemed to be working right. After a couple minutes the problems started.

I think one of the best suggestions so far is maybe a bad coil. This is an intermittent type problem though.....

Here's one of my videos:

http://www.youtube.com/watch?v=DKbWcw2JRY8&feature=related

So, if you're still with me this far into this thread, or saga might be a better term, I would really appreciate some advice or thoughts.

********************************************************

UPDATE:

A couple more ideas from people in my other thread:

Check the wires from the stator to the powerpack, sometimes they rub the bracket that holds the powerpack. Check the powerpack ground.

Take a timing light with you and check fire to each cyl, if firing ok check carbs.

 

[tashasdaddy]

Re: Summary of my issues (1990 50 hp Johnson)

check spark on both cylinders immediately when it starts to falter. it is not that hard to do on the water with a spark tester. also read ethanol in TOP SECRET FILE.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

Can an engine idle nicely on one cylinder, or with a weak cylinder?

Will I be able to connect the spark tester and give it enough throttle to get to the speed where the issue occurs?

 

[jonesg]

Re: Summary of my issues (1990 50 hp Johnson)

Can an engine idle nicely on one cylinder, or with a weak cylinder?

Will I be able to connect the spark tester and give it enough throttle to get to the speed where the issue occurs?

You really need to buy some cheapo troubleshooting tools, a timing light and spark gap tester will cost less than $40 total.

Thats the only way to find out if its dropping a coil on the fly.
Its probably gonna come down to a failing coil under load or power pack.
This is a simple problem really.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

I think I will. I have a lot of work to do on this boat over the winter, so I might as well add some more mechanical tools to my list.

As for these problems, I'm going to take the boat to the shop in the morning. I hope they will look at it right away since this is still basically working on the problem from my original work order....and they said it was fixed. I'm guessing it wasn't run long enough in their test tank for the problem to show up.

I wish this problem wasn't so intermittent in nature.....I mean.....it ran perfect for two minutes today before acting up. then it was continuous afterward.

I just need my boat working for the cottage....

 

[michael37659]

Re: Summary of my issues (1990 50 hp Johnson)

Try your reg/rectifer,i was having similar problems as you with my 50hp.I unhooked it completely and started my motor and ran it to check it.

 

[clanton]

Re: Summary of my issues (1990 50 hp Johnson)

This engine has SLOW.
Repair the overheat alarm.
Check wires from the powerpack to the coils, starboard side of engine, sometimes rubs bracket.
Check powerpack output voltage to ignition coils, while running boat in water. 200 volts with peakreading meter.
Insure VRO pump and oil tank wires are unplugged and secured.
Insure temp sensor (tan wire) has NO voltage.
Check diode in tan wire, on engine.
Check coil for arcing to block.

This ignition system CD2USL had lots of pack failures.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

Thanks Clanton.

I dropped it off at the shop today and showed the mech my video. He said that it looks like a protection systems thing and raised his eyebrows a bit when I told him that I had unhooked the temp switch and it didn't make any difference. I think that was his first guess.

He ordered a power pack. If my motor needs it, great. If not, they didn't have one in stock right now so he wanted it anyway. Plus, it usually takes a couple days to get parts in so the order has to get out quick based on my time table.

I told him that I'm in a rush to get the boat done for the weekend because I have to leave for the cottage.

He said that they can't run the motor at full load for very long in the tank with the test prop.

Fingers crossed.......

 

[jonesg]

Re: Summary of my issues (1990 50 hp Johnson)

Thanks Clanton.

I
He said that they can't run the motor at full load for very long in the tank with the test prop.

Fingers crossed.......

noise , exhaust fumes?


Nice job on the carb rebuild pics by the way.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

From somebody else's old thread:

hello<br /> the cd2usl was not (reliable). had a tendancy to trigger slow for no apperent reason sometimes. get her mounted and hooked up and tell us how it does<br /> make sure you have an accurate tach for testing.<br /> cross your fingers on the clutch dog

Interesting.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

Haven't heard back from the shop yet, but feeling good about the power pack.

Either the power pack is toast, or there is a bad wire in there somewhere. Considering what you have to disassemble to get to the PP to test it, the likelihood is very good of finding a fault in the wires.

I'm pretty stressed out about my boat....I leave Saturday morning for the cottage and I need my darn boat!!! AHHHHHHHHHHHHH!

I'm so tempted to call and pester the shop, but I know that does no real good. I'd rather be the customer they like and *want* to service well and develop a good relationship with.....

But yeah...the more I read about the power pack, specifically the CD2USL, I think that may be the problem. That's also where my SELOC manual points too...high speed misfire on motor with good spark = Power Pack.

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

Thankfully, I got my boat out of the shop today.

I leave for the cottage in the morning.

I have not water tested the boat yet.......so I'm nervous. They said it was fixed last time too.

However, I feel pretty good that it will be fixed right this time.

They did replace the power pack, and they checked all the wiring looking for shorts, worn wires, etc.

The mechanic said that what my motor was doing was indeed SLOW. Since I had tried the motor with temp switch unplugged, and my VRO is disconnected properly, the only thing that could trigger slow is a bad power pack.

 

[billsnogo]

Re: Summary of my issues (1990 50 hp Johnson)

Well? Need an update! Don't leave us hanging man

 

[22E6441]

Re: Summary of my issues (1990 50 hp Johnson)

Sigh......back home again......will be missing the cottage for the next 51 weeks.

On a positive note, the power pack was the culprit.

The boat ran perfect at the lake all week.....had the kids tubing, didn`t try them skiing though. My sister has a bigger boat that we use primarily as the water sports boat. A big old Crestliner 175.

So yes, my power pack was acting up and triggering SLOW for no reason.

Changing the power pack solved the issue.