All techs are left stumped on 96 200 ocean pro firing problem - The Hull Truth

Reel Mayhem · 07-04-2007, 06:03 PM

I have a 96 200 Johnson ocean pro ( plastic carbs ) we've put a complete new ignition system as well as harness, dva'ed and ohmed every part. Large batt. cables directly to engine,OEM brand new factory starter. The engine has very weak, errattic spark and will not crank. Spins over great but will only crank if 24 V. are put to it then it fires off great on 12 V. with only a bump of the starter for the rest of the day & night. The starter IS the correct gear reduction one. I have only one last possible fix and would surely appreciate any help you may have.

A1 Outboard · 07-04-2007, 08:03 PM

Anyone check the center in the flywheel ? ??

Reel Mayhem · 07-04-2007, 08:16 PM

Flywheel hub is good. All I can surmise now is weak magnets but I don't know how to test them. It seems as though once energized, it starts fine. I don't usually let inanimate objects get the best of me but this one just may.

A1 Outboard · 07-05-2007, 09:09 AM

Quote:

Reel Mayhem - 7/4/2007 5:03 PM
Spins over great but will only crank if 24 V. are put to it then it fires off great on 12 V. with only a bump of the starter for the rest of the day & night. The starter IS the correct gear reduction one.

Most of the hard starting complaints for that engine are due to improper procedures, slow cranking speeds (needs about 300-350 rpm), or fuel deposits in the priming system hoses or fittings.

For a cold start, hold the primer ball vertical, arrow up and squeeze until rock hard. It should be a factory ball, not a gray or other brand. If it doesn't get rock hard, find out why. With the motor trimmed all the way down and the throttle closed in neutral, push the keyswitch IN and hold for 5 seconds, while continuing to hold the switch IN, crank the motor over and it should start within 10 seconds. If not, troubleshooting is needed, most likely the following procedures. Once the motor starts, you may have to "bump" the keyswitch to keep it running until it gets warm enough.

If you have the kill switch that clips around the key and physically turns the key off when pulled, make sure that it is attached !!!!! Without it, the key pops back to OFF very easily when pushed IN to "choke".

When the motor is running, set the fast idle to about 1500 in neutral and then push in the key switch and hold. The motor should start to run rough, smoke, and slow down to about 7-800 rpm. If not, the primer system is not delivering enough fuel for a cold start, and each nipple and hose should be checked. Some folks drill out the brass nipples about .005-.010" to help starting.

The magneto ignition system needs enough rpm to generate voltage to fire the plugs. With the sparkplugs installed, hook up a 6 cylinder spark tester such as a Steven's or MercTronic with the gap set to 7/16", crank the engine (cold motor) and make sure the spark jumps each point and is strong.

Mr. Bee

Reel Mayhem · 07-05-2007, 10:45 AM

Thanks, we've went through all the processes. The spark is very weak and inconsistent until we put 24 V. to it. Once it hits one time, ( not crank ) we can run 12 V. and spark is strong and consistent. It does'nt have to start to produce this, just pop one time. I've tried warming the engine with a heat gun prior, to no avail as well. The engine is tuned and sync'ed, fuel system is good. Is it possible that by using 24 V. at first, ( raising RPMs to 425 ) that it " energizes " the flywheel magnets ? CDI electronics have developed a prototype ign. system to correct this very problem however the test results have'nt concluded so far as i'm aware. Besides they want $ 800.00 for the system, i'll add a battery switch to run batts. in series to spin it over that first time before I pay that. I've been waiting for one to come through the shop so that I can try a known good flywheel instead of just spending the $$$ on a magnet kit. Do you know of a way to test the strength of the magnets ?? I really feel this is where my problem lies and mine isn't the only one from the research i've done. Any further help will be as appreciated as is the advice you've given so far. I've read through many of these threads and you do a great service to THT'ers, thanks and keep it up, Wade.

A1 Outboard · 07-05-2007, 06:45 PM

To test the outer magnets, hold a screwdriver loosely over 1" away and slowly move it towards each magnet, it should jump to the magnet from about 1". The inner magnets, all you can do is "feel" if each has about the same "pull". A known good flywheel is the only true way to test if yours is bad.

What rpm does your motor turn over cold with just one battery? Have you tried a new starter?

Has a tech checked the timer base output voltage and the charge coil voltages and the pack output voltages at cold cranking speed with the plugs installed? What were the voltage numbers? Don't accept a "they are OK" type of answer.

Reel Mayhem · 07-05-2007, 08:00 PM

I am a tech, hence the frustration. I have had others more qualified than I involved as well. It's been a while since i've messed w/ it so I don't know exact #'s but they are/were within spec. I get parts at cost and out of frustration overruled results and bought an entirely new Ign. system, including starter. RPM on 12 V. is 340, it spins great. I just tore the powerhead down for a rebuild ( wrist pin bearing goin ) and will put in new magnets if I still run into this. I'll post results. Thanks for your input, if you think of anything else, i'll be watching.

A1 Outboard · 07-05-2007, 08:16 PM

Are you sure it is not a fuel problem thru the primer system on a cold start? That is very common on that type of engine. There is a procedure for starting the motor cold.

Reel Mayhem · 07-05-2007, 08:57 PM

I may need to revisit that. I did the spark tests and strayed from the fuel sysem. Plugs are always pretty wet though. Of course bein a rebuild now, I will go through it all and will pay special attention to the primer system as I know these engines are hard cold starting. Thanks very much for all your help !!!! I'll let you know what the outcome is. As I said, you provide great knowledge to this forum, keep it up, it helps many !!!

Mac25 · 07-06-2007, 09:37 AM

try it with a new ign switch.