Black Max 150 has me baffeled

[kendo]

Re: Black Max 150 has me baffeled

John, Mark and others thanks so much for the info and ideas I'll try them all at this point. O.K. Here's where I'm at:
First off serial # is A181505 and the motor is the standard 150 with tilt, trim, oil injection, one small rectifier with 3 wires, red and 2 yellow. The grey tach wire is on the first yellow from stator. the idle stabilizer is in the back above the port cylinder bank and has three wires white/black, red/white and a black ground. The idle stabilizer is of real interest to me at this time as it has been brought up by several responders. The fact that it does attach to the switch boxes and jumps both with the white/black wire on the first terminal could be the problem. I'm not ruling out anything at this point but I tend to lean towards ignition rather than fuel. I have used an external tank, replaced the hose and bulb and ran the fuel line direct to the oil pump illiminating the merc coupling. I have replaced the switch boxes, stator and rectifier which has helped but not solved the problem. Today I took the trigger assembley off and checked all the wires. With the ohm meter checked as directed and found all numbers 1230/1240/1240 give or take a fraction. Book suggest numbers between 11/14. Also tried bending wires in loom numbers stayed the same. Wrapped and securred the wires and ran the harness in the least tension setting.
A buddy said trade her in but I said she's mine, I just have to let her know whose boss. Right guys?
John, I was unable to forward pictures could you give me your email address and I'll get them to you. dumar11@hotmail.com thanks again. Kendo from Wi.

 

[kendo]

Re: Black Max 150 has me baffeled

Martin, while have a reasonable amount of experience with engines in cars and sport bikes I must say that I am fairly new to this whole outboard engine stuff. It sounds like you have some good information in your post but if you would please elaborate more on what you are talking about so that I may have a better idea on what I need to do and look for it would be greatly appreciated as I am having similar problems with my 1986 XR2 150.

Speedy 150, I havn't forgot about you or your frustrations, I just havn't figured mine out yet. I'm sure you have been reading the posts to my problem, there are a lot of good ideas out there and I really appreciate the help. New rectifier didn't change anything except now I have a spare. I'll be out testing soon as the rain stops, hope to have good news. Keep the faith, Kendo.....

 

[j_martin]

Re: Black Max 150 has me baffeled

Kendo,
The idle stabilizer is prime suspect. The engine should run just fine without it. It certainly won't be hurt. Like I said, it is NLA at merc or anywhere else except used or New Old Stock, because it is an unneeded part.
If it's that screwed up, you may find that your idle is way off all of a sudden, which would indicate that whoever did the link and sync last did not disconnect the idle stabilizer as instructed in the procedure.

You can check out the diode with an ohmmeter. If it is bad, it will screw up the tach, along with not charging the battery. The mounting screw ground on it is critical to both charging and tach circuits. Mercury does not stock it because it is junk and the aftermarket diodes are better for half the price. For 3.50 or so, or even less at a surplus store, you can get a 25 amp, 200 volt or more bridge rectifier and rig it in, and never have another problem.
Or you can rig in a CDI 20 amp regulator and have a superior system to the original. It's about 100 bucks.

You described the modules well, I don't need the pictures.

A pressure gauge either convicts or acquits the fuel system.

The stator and diode should have fixed the tach problem.

hope it helps
John

 

[bigshrimpin]

Re: Black Max 150 has me baffeled

I agree with John . . . Throw that idle stabilizer in the garbage.

 

[studlymandingo]

Re: Black Max 150 has me baffeled

Where are you guys in getting the 150s going? Sounds like you've eliminated much of the potential for electrical issues.​

 

[kendo]

Re: Black Max 150 has me baffeled

Bigshrimpin,

The idle stabilizer is good as gone. Question, when I disconnect the two idle stabilizer leads on the switch box (white/black and red/black) should I remove the jumper from the first terminal between the 2 boxes or should they stay tied together? Tried it last night on the muffs on the driveway with the wht/black wire diconnected and she idled just fine. Thanks, Kendo

 

[Speedy150]

Re: Black Max 150 has me baffeled

Last Thursday I took the old gas out, drained the tank and aired it out. Friday put new gas in it and used the water cups and see how she ran. It started surprisingly easy despite sitting for 2 years. Let it idle for a little while and checked the plugs. Plugs 1,3,5 looked fine, plugs 2,4,6 however had a heavy build up of oil and looked like they were not firing even though they sounded like they were. We swapped the 1,3,5 with the 2,4,6 to rule out a bad plug but to no avail. Took it out to the lake Sunday to see what she could do under load. It was hard to get it up on plane and the bulb would not stay hard at all. Sounded like it was not getting enough gas which would coincide with the soft bulb. It ran very unstable, sometime able to get up to 4k rpm, and others hardly able to get over 3k and plane out. With the throttle 1/2 or buried it would rev up then down and repeat until it would finally get up only to lose power and come back down. Does this sound like a fuel pump? This boat has set all its life and I would guess it has a total of ~50 hours on the engine.

 

[studlymandingo]

Re: Black Max 150 has me baffeled

If you had some issues with the plugs, I would first look for spark issues. A spark-gap tester can be purchased at a local auto parts store for around $5. Check each cylinder for a strong consistent spark.
You could have stator or switchbox issues.

Rebuilding the fuel pump would be a good idea if it has been sitting unused for two years. Rebuild the water pump as well.​

 

[Speedy150]

Re: Black Max 150 has me baffeled

The spark plugs that are in the motor do not have a wayt to adjust the gap I don not believe. They are the flat type not the conventional car type with the inverted L over the gap. Is this the correct type? Or should I be using the conventional type?

 

[j_martin]

Re: Black Max 150 has me baffeled

Bigshrimpin,

The idle stabilizer is good as gone. Question, when I disconnect the two idle stabilizer leads on the switch box (white/black and red/black) should I remove the jumper from the first terminal between the 2 boxes or should they stay tied together? Tried it last night on the muffs on the driveway with the wht/black wire diconnected and she idled just fine. Thanks, Kendo

The white/black jumper wire is the bias wire. It connects the two switchboxes together so they are on the same page, timing wise.

Hope it helps
john

 

[j_martin]

Re: Black Max 150 has me baffeled

You have two problems
1. You hijacked Kendo's thread, confusing things
2. You have a bug nest in the fuel tank vent.

hope it helps
John

Last Thursday I took the old gas out, drained the tank and aired it out. Friday put new gas in it and used the water cups and see how she ran. It started surprisingly easy despite sitting for 2 years. Let it idle for a little while and checked the plugs. Plugs 1,3,5 looked fine, plugs 2,4,6 however had a heavy build up of oil and looked like they were not firing even though they sounded like they were. We swapped the 1,3,5 with the 2,4,6 to rule out a bad plug but to no avail. Took it out to the lake Sunday to see what she could do under load. It was hard to get it up on plane and the bulb would not stay hard at all. Sounded like it was not getting enough gas which would coincide with the soft bulb. It ran very unstable, sometime able to get up to 4k rpm, and others hardly able to get over 3k and plane out. With the throttle 1/2 or buried it would rev up then down and repeat until it would finally get up only to lose power and come back down. Does this sound like a fuel pump? This boat has set all its life and I would guess it has a total of ~50 hours on the engine.

 

[Speedy150]

Re: Black Max 150 has me baffeled

I have not hijacked Kendo's thread, it sounds like the problems that he and I are having are one and the same. The similar engines, same year, same problems sounds to me like. So I was hoping that if he can solve his problem maybe it would be the same thing mine is suffering from.

 

[j_martin]

Re: Black Max 150 has me baffeled

It's a different problem.

I have not hijacked Kendo's thread, it sounds like the problems that he and I are having are one and the same. The similar engines, same year, same problems sounds to me like. So I was hoping that if he can solve his problem maybe it would be the same thing mine is suffering from.

 

[j_martin]

Re: Black Max 150 has me baffeled

Kendo,
Have you had a chance to run it without the "idle stabilizer" yet?

John

 

[kendo]

Re: Black Max 150 has me baffeled

Studlyman, John and others:

Thanks for following up, I wish I had some good news for all of you. Removed the idle stabilizer and synched the timming with the carbs, negative results. Took her out for a spin today, fired right up idled like a sleeping baby. Hit the open water put the hammer down and we just creeped up on plane. 32mph, and 4000 rpm. Made lots of noise and went no where. Would never pull a skier. All cylinders are fireing and feel the same temperature wise. This is starting to remind me of my old lawnboy when the exhaust port carboned up or like when I put the potato in my gym teacher exhaust pipe on his 73 VW. Slow ride home. I'm not giving up, with all this help I'll figure it out, the glass is still half full. Also disconnected the control harness from the motor and used a remote key and harness borrowed from my friendly Merc mechanic. Looked for a short in the wireing didn't make a difference. Going back out tomarrow with a spray can full of gas, havn't tried that yet. Thanks again, Kendo

 

[studlymandingo]

Re: Black Max 150 has me baffeled

You don't have a bunch of waterlogged foam somewhere do you?​

 

[j_martin]

Re: Black Max 150 has me baffeled

Kendo,
Have you checked the fuel pressure while running with a gauge?

Gotta clear that one out of the way.

Hell, this is a 2 cycle engine that once was running like a dream. There just ain't that many things that can go wrong. The only moving parts either move right or go out the side.

John

 

[Carbkid]

Re: Black Max 150 has me baffeled

I had a similar problem on a 89' 90hp Merc that I was working on for a friend. Compression was good, spark was good, cleaned carbs half a dozen times, ran good in the drive way with the muffs but would not get up on plane out on the water. I replaced the rectifier to no avail. Finally bit the bullet and put in a new STATOR and she ran like a raped ape. This might be your problem. I was nervous as hell to drop that kind of money but it took care of the problem. Good luck!

 

[kendo]

Re: Black Max 150 has me baffeled

Kendo,
Have you checked the fuel pressure while running with a gauge?

Gotta clear that one out of the way.

Hell, this is a 2 cycle engine that once was running like a dream. There just ain't that many things that can go wrong. The only moving parts either move right or go out the side.

John

Sorry for the delay, had to wait for the weather to break. While waiting I did hook up a vacume gauge between the primer bulb and the hookup on the oil pump. According to Merc. this should read less than 2 showing no restrictions in the line from the tank. It read between 1 and 2 flowing plenty of fuel. Next I went to the other side on the bottom carb with a pressure guage and at idle she hung about 2. On the lake today at W.O.T. she read between 3 and 5, bouncing quite a bit. Still plenty of fuel. Next we ran with the carb cover removed and squirted raw gas into the venturies. Engine actually slowed several times like flooding. Had the same experience activating the enrichner while under way. Next giving some thought to the weight of the boat problem (saturated foam) which shouldn't be, strored inside most the time and covered I changed props to try and pick up some revs. Went form 14 1/2" by 21 pitch to a 14 by 19 both stainless. Same top rpm with both, 3900 and 32mph. Disconected my tach hooked up a external tach which read fine and was not affected by the power draw of the tilt and trim. I guess I need a new tach, solved that problem. Attached a volt meter to the battery and she ran between 13/15 under all conditions. Never went below 13 even with all acces. and trim activated. Plenty of juice to run the stator. What did I learn, Either the carbs are set to rich ie. float levels or needle and seat or the trigger is keeping the revs down. Whats your thought? The carbs are coming off today, that's a cheapy. I took someone elses word that they were o.k. Same guy that sold me on crank seals. Thanks for all your time and know how. Kendo from Wi.

 

[j_martin]

Re: Black Max 150 has me baffeled

Kendo,
That pretty well eliminates fuel as the problem with one caveat. I would think at 3900 rpm, it should be pretty steady at anything above 3 PSI. Normally I think it would be a little higher. It's possible if you have a lot of air in the gauge line that it's actually going to 0 and the gauge isn't reacting. If the line is short, or wet, that's a mute point.

Don't junk the tach yet, it may just need a capacitor on the power to filter out noise from the tilt.

If the carbs don't flood severely just from a normal squeeze on the primer bulb, they probably aren't bad enough to cause this problem.

Here's what you need to know about the stator.
There are 3 sets of coils on the stator.

1. One set runs the battery charging whatever, from a rectifier to a voltage regulator. Makes no difference, it's a stand alone circuit. On that engine, battery voltage or condition has nothing at all to do with how the engine runs.

2. Another 2 coils, called charge coils, supplie the power to the switchboxes for spark below a certain RPM. (Low speed charge coils.)

3. Another 2 coils supply the power to the switchboxes for spark above that same RPM. (high speed charge coils)

If one of the high speed charge coils were bad, it would drop three cylinders on one bank above a certain RPM, I think about 3000.

One of the switch boxes could also be bad.

To track it down, run a timing light on the top plug of each bank (one at a time unless you have 2 lights) and take it out for a ride. If the light goes out or gets erratic, you've identified the bank.

Now swap the switchboxes. If the bug moves to the other side, it's the switch box. If it stays on the same bank, the stator is bad.

Maybe one of the other old timers has another procedure for tracking it down.


hope it helps
John