1989 black max needs CPR STAT!!!

[vipertec]

my engine years ago developed a problem where under accel would lack full rpm.It would jump up about 500 rpm after say 5 min driving and be ok.Eventually got to to the point of only getting up to 1000 rpm ,could not get on plane until 1/2 hour of messing with it.I am an auto tech by profession,with minimal outboard experience,so i tryed fuelrime bulb under accel,cleaned carbs,rebuilt fuel pump,:n/g.still clears upafter 1/2 hour.Took to canada and still acted up so took to dealer to find out stator n/g.Got home and replaced,still n/g.So i parked boat for 3 years.Now attempting to repair my trim is stuck up and only relays click.Is there a common issue here and if motor is that, can I repair,parts available?
As for poor driving any info or diag would be appreciated,possible"black boxes"or switch boxes faulty.Last ,if i can resolve these issues i would like to replace water pump.I have done one on a force 50hp,would it be similar?thanks for any input.

 

[sschefer]

Re: 1989 black max needs CPR STAT!!!

Did you ever check the compression on the motor?

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

Yes when i ran it last[3 years ago} and they where all within 10 psi of each other and within spec for which i dont remember what it was,when i drive it it feels as if i m pulling 10 skiers and every minute one drops off.The rpms start to jump up in increments until boom,full rpm achieved.

 

[j_martin]

Re: 1989 black max needs CPR STAT!!!

What's with the STAT bit? You've been letting it go for years.

Do a compression test to see if you've burned it down yet. Ain't worth doing a lot of "tune up" stuff on a broken motor.

 

[sschefer]

Re: 1989 black max needs CPR STAT!!!

The trim problem is probably just a gummed up pump motor. You can take them apart and clean them but sometimes it's just as easy to replace them with a rebuilt.

As for the running problems. I'd pull the plugs and fog the cylinders then turn it over by hand with the plugs out to make sure it's turning over freely.

Following that, I'd get it running on a small fuel tank with fresh fuel and 100:1 pre mix just incase the oil pump isn't working.

If it runs, and the oil pump is pumping then add 1 can of SeaFoam to 2 gal's of fuel and run it for 15 min. Let it sit for 15 minutes and repeat. Do this 3 or 4 times our until most of the fuel is gone.

If the oil pump is pumping oil and everything looks good then start it back up on the small tank with fresh high octane (90 or 91) non ethanol fuel.

Put a fresh set of plugs in it and take it to the ramp. Back down the ramp with the boat strapped on the trailer and put the motor in just deep enough to cover the cavitation plate on the lower unit.

Set your max advance timing to 19 degrees if you motor had the advance module or 23 degrees if your motor does not have the advance module.

Run the motor in gear up to 1500 RPM and see how she acts then let us know and we can go from there.

The bottom line is that we need some fresh symptoms to work with before we can begin to help you.

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

Have to little children so time was limited and a bass boat was not infant friendly but they are a littte older now so they would like to go out.Will check comp this week.could you provide the specs.thank youy

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

i have always put new plugs every season and motor will turn over,will try fuel tips and get back to you.thanks

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

well, today i finally got to check some stuff out.Icharged up the batteries and proceded to start boat.It started .So i disconnected each coil one at a time and used an adjustable spark tester on each cyl.Cylinders 4 and cyl 5 both had weak to no spark.Now I set the gap on tester fairly large(aprrox 1/2)and all other cylinders had huge crisp spark.I swapped coils from side to side and still #4 cylinder would not have spark.Itook pos. feed from another coil and hooked up to 4 and have great spark.Now it seems as if the driver for the coil is defective.The two cylinders with issues are on opposite switch boxes.I ohmed the leads and have less than.5 ohms.Is there a better way of testing output to trigger coils to determine the cause?thanks.

 

[Chris1956]

Re: 1989 black max needs CPR STAT!!!

Check the CDIElectronics web site for the troubleshooting procedure. It should narrow it to Stator or trigger problem.

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

check the cdielectronics web site for the troubleshooting procedure. It should narrow it to stator or trigger problem.

i replaced the stator last year for this problem.what controls the triggering for the coils?the switch boxes?

 

[sschefer]

Re: 1989 black max needs CPR STAT!!!

1. 4 and 5 are on different switch boxes.
2. 4 and 5 are on different trigger coils.
3. Weak spark on 4 and 5 only, does not indicate a stator problem.
4. The bias circuit in the switch boxes is jumpered with a white/black wire on the far left top terminal of each box.

A faulty bias circuit in one switch box is consistent with your symptoms. Disconnect the bias jumper wire on the outer switch box and re-check your spark. It the problem is now on one cylinder only, replace the switchbox for that cylinder.

 

[j_martin]

Re: 1989 black max needs CPR STAT!!!

Hope this helps.

Stator supplies power to switchboxes, different coil for each one. A failure will usually cause one bank to fail, ie 1,3,5.

Switchboxes are each a group of 3 independent coil firing circuits. Can fail on 1, 2, or all 3 on a side.

Coil, one per cylinder, easy to swap and test.

Trigger has 3 coils in it. Each fires 2 cylinders opposite in timing, ie 1 and 4, 2 and 5, etc. Usually a failure causes 2 related cylinders to fail.

A switchbox failure, through the trigger, can cause a misfire on the other switchbox.

When you look over the above pile of factlets, you begin to understand why switchboxes should be replaced in pairs. I'm afraid from the symptoms you describe the fault is in the switchboxes.

One thing you need to know is that if you push a big 2-cycle that's acting up, and the problem is timing or too lean fuel, it's real easy to burn down one or more pistons. Before you waste any more time and money on this engine, I'd do a compression test. Should be 110 - 140, depending on lots of things. Big thing is that it's fairly even across the board.

I understand the kids thing. I'm just about to toss #9 out of the nest.

hope it helps
john

 

[vipertec]

Re: 1989 black max needs CPR STAT!!!

i printed diag off of cdi website.When checking resistance is that thru the box it is checking and when checking voltages the boat should be cranking or running i am assuming?