Ignition 1992 Force 120hp. must read to understand this bizaar issue.

[jamesnoll]

I took my boat out last weekend. After getting it off the trailer it stalled I restarted it and it stalled again and would not restart. I pulled the motor cover off to check it out. The only problem I found was the one fuse above the switch block blown. I replaced it and the boat started right up. Took the kids tubing and then stopped for dinner. After dinner hopped in the boat and it start right up. Drove the 5 miles to the boat ramp and then it stalled again. I tried to restart but it would not restart. Paddled to the dock pulled the boat out and drove home.

The next day I tried to start the boat on the muffs but it would not start. Started checking the kill switches.(lanyard and the shift switch) all tested good. Kept trying then it started. I was able to start it a couple of time but then it stopped and I was not able to get it started again. It was late so I put my tools away.

Day 3 I tried to start it again but nothing I pulled the plugs and they seemed to have a spark but not strong and the boat would not start. I thought maybe I got water in the fuel so I pulled the bowls off the carbs but they were clean. Nice fresh gas in both bowls.

Day 4 After reading some trouble shooting info on CDI website I thought I would test the electronics. I was think that my trigger may have failed. I took my handy multimeter out to the boat and test the stator out put. The voltage read as AC where 47v on one leg 8v on another leg and 15v on the voltage going to the voltage regulator. I also wanted to test the trigger but was not sure what I would get. While I had my wife turn the boat over I put my leads on the ground and on each one of the four legs of the trigger. I left the spark plugs hooked up as the motor was not starting. When I put the lead on the last trigger wire I got a pop from the motor and it started to run. Yes, it startled me and I jumped the motor died when the leads came off. So I turned on the water and did it again. Yes the motor ran. It ran rough but it ran. So then I tested it on the other trigger wires and got it to start on the last wire as well. But as soon as I take the leads off the motor dies.

Question would this mean my trigger is bad or my switch box bad? Your thoughts, opinions, and question are welcome. I am stumped and need help. The switch box will cost about $250 and the trigger about $80.

Jim

 

[Frank Acampora]

Before you go too crazy, try checking the ground wires of the trigger: Remember: With your meter, you artificially grounded the trigger wires to a good ground. ALSO check the ground from the electronics mounting plate to the engine block.

 

[jamesnoll]

Frank the harness coming from the trigger only has 4 wires. It is the original trigger. The new ones seem to have a fifth wire which is the ground. I was wondering if the OE was grounded through the mounting hardware. I have not pulled the fly wheel yet but will try to pull it this weekend and see if I can figure out how it was grounded. The mounting plate is ground and the wire and connection point are good in like new condition. If you are familiar with the OE connections and can provide any input it will be greatly appreciated. Thank you for your input.

 

[pnwboat]

Sure sounds like a bad connection. Do like Frank suggested and check all the connections on the Switch Box, coils, and stator to make sure you don't have any bad or broken wires.

 

[Jiggz]

It's a loose connection that gets connected when you touch one of the wires. Check by disconnecting and cleaning and making sure there is no scaling in the connectors. Use terminal or contact cleaner (Radio Shack has it) to make sure you have good connections. While at it, you might as well check also the stator connectors and other connectors

 

[jamesnoll]

Ok, I dug int the issue and pulled the fly wheel and removed the stator. I believe the issue is with the stator. It look like I am having a melt down. After testing the ohms it is low by a 1000 ohms compared to CDI information. I will try replacing the stator and see what happens. If any of you know a good place to get a stator for a good price bounce me back a message.

 

[Jiggz]

Can you post a pic of the stator focused on the melt down you are referring? CDI if probably the best source for brand new stator and *bay for used ones including NOS (new old stocks).

 

[jamesnoll]

All right I got the new CDI stator and installed it in the boat. WOW what a difference. Now when I start the motor it pops quick. Running the boat out of water and on muffs it seem to have a more aggressive pop in the exhaust. Moving the throttle to high idle seem to have a better variable throttle. So far everthing seem to run just a little better.

First note the boat with old stator would only get up to about 5200 rpm with an aluminum prop and popping on plane seem a little slugish. I also have a composit prop and with that installed my rpm would max at about 4600. when idling in gear the motor would die. Turn the key and it fired right back up. This was a pain in the @$$ at the boat ramp or the docks. I always contributed this to a fuel delivery issue. But that is how the boat seem to run for years. This season seemd to be worse.

Now for the in water test run.
So I took the boat to the lake and backed it down in the water. My wife pulls the boat off so she is the one that starts it. It took a couple of tries but she got it started seem normal as the way it started before the stator replacement. With the boat started she pulled off the trailer and motored around waiting for me to park the truck. When I came back down to the dock she pulled right up for me to board with out the motor stalling. What a relief that was. We headed out slow and once past the no wake zone I opened the boat to get in on plane. It seemed to jump right on to plane and felt like it had power like it did when it was new. The lake was calm so I spooled the motor to WOT. Without any hesitation the boat took off. I reach 45mph very quickly and easily reach 5500rpm. I pushed it as hard as I could and the boats rpms actually climbed to almost 6000 rpm. This is a little scary as the operating range is 5500 rpms. The boat seem to be running great and idling with out any hesitation or stalling. All my test were done with the aluminum prop and I am very pleased with the performance.

I then installed my composite prop to see how it performed. The boat ran good with out stalling during idling but as for WOT the boat would only spool up to 4800 to 5000 rpm and my top speed was around 40 mph. I am not sure why as I would think if the prop was flexing I would get the same RPM's but a slower speed. I wonder if the aluminum flex more which would take some pressure off the torque and may be let the RPM spool higher. Any thoughts are greatly appreciated?


I cannot upload a picture for some reason. But if you want to see the picture of the old stator you can go to the following dropbox link.

https://www.dropbox.com/sh/jhbu99b3qxb0usp/AAAPPGQmF7V4H9uXiEeFVP-Ea

 

[Jiggz]

Saw the pics and you are correct the melt down is a sure sign wire insulation inside has started to failed which caused a short and overheating thus the melt down. As for the prop, I would surmised the cause of slower WOT RPM and speed is the difference in "cupping" of the prop blades. You did not mention if the pitch and diameters are the same, but I assume they are. I'll stay with the Al prop for now while limiting your WOT rpm to no more than 5500. Obviously with additional loads on the boat, WOT RPM will eventually go down to 5500 rpm.

Since the motor is now running and idling great, now is the time to tune it up well starting with the idle mixture and idle screw settings. Re-verify timing and also ensure plugs are correct and not fouling.

Congrats and enjoy!

 

[jamesnoll]

Jiggz

You are correct the props are the same size and pitch. The plugs are new and good. The motor was tuned prior to the stator failure but will go through the mixture and timing to make sure I am getting best performance and fuel economy. As for the prop cupping I did not think of this but plan on doing some research to see how much of a difference this can cause and if there is anything I can do with the composite prop. I am running the Al but will keep the composite prop for emergencies.

Thanks for your assistance and input. It is greatly appreciated.

Jim