Update and more questions Merc 150 (Update)

[LubeDude]

Ive posted several times about the problems Im having to no avail, and I have an appointment this coming week to have it looked at, but I worked on it all day doing different things. New battery, new water separating fuel filter and checking all connections. I took it to the ramp this afternoon, (five minutes from the house) And backed it in the water just to start it and see if anything has changed, NOPE, everything the same. I did notice something I never noticed before, as I ran it on the muffs before and didnt want to rev it up very high. When I reved the engine to 1,500-2,000 RPMs, the horn beeped intermitently untill I pushed the fast idle down, then when I would do it again it did the same thing. The oil injection is working fine, plenty of smoke, whats happening? Im thinking switch box. The first time it did it, it took awhile before the horn went off, maybe a minute.

 

[mellowyellow]

Re: Update and more questions Merc 150 (Update)

refresh our memory LD... what's she doing and what<br />have you eliminated so far or replaced/repaired?

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

The easiest way to tell you is, I have rebuilt, or replaced, everything on the ouside of the engine, but the electronics, New fuel pump last year and new fuel lines and bulb pumps solid and holds firm. Engine is very speratic, Misses, seems to cut in and out. troughout the RPM range. Starts easy and seems to Idle as good as a 150 Merc Idles.

 

[KCLOST]

Re: Update and more questions Merc 150 (Update)

Lube,<br /><br />Check the spark on all the cylinders....<br /><br />This could be one of the switchboxes.... Could also be causing the intermittent alarm problem... Let us know....

 

[quantumleap]

Re: Update and more questions Merc 150 (Update)

Try putting in a petroleum based oil and I bet she'll smooth right out!

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

Spark is all there at Idle, hard to check when going accross the lake. compression is 120# all the way across, + or - a pound or two.<br /><br />I havnt changed it over to synthetic yet, waiting to get it running right first. ( I know youre just funnin anyway)!

 

[Trent]

Re: Update and more questions Merc 150 (Update)

From what your saying it sounds like a "High Speed Miss" If so do this....<br /><br />Disconnect the rectifier and retest. If the miss is gone, the rectifier is usually at fault. If the miss still exists, check the DVA voltage (between the red wires on 4 cylinder, or red wires to engine ground on 3 &6 cylinder) of the stator at high speed. NOTICE: Use caution when doing this and do not exceed the rated voltage range of your meter. The readings should show a smooth climb in voltage. If there is a sudden or fast drop in voltage right before the miss becomes apparent, the stator is usually at fault. If there is no indication of the problem, it could be a small water leak in one or two cylinders. Look at the sparkplugs for "an extra clean sparkplug".

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

It doesnt run smooth at any speed , and whats making the horn go off. beep, beep, beep, constantly when you lift the fast idle lever, then when you release it, it stops, then when you lift it it beeps constantly again. I tested the stator, and it tests like the new one I tested it against. When you give it any throtle after it warms up a litle, it goes, da da da, da da, da da, da da,da, da da, da da da, there is no smoothness to it ever. When it is cold it will try and run fine untill it runs for 30 seconds or so. Then the horn goes off and it starts the serious missing. something electrical is warming up and quiting.

 

[mellowyellow]

Re: Update and more questions Merc 150 (Update)

find a quiet ramp with nobody around, back her in<br />and test spark under load and at higher rpm's.<br />post results.<br />good luck,<br />M.Y.

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

Took boat into dealer yersterday and the general concensus is that the outer switchbox took a dump. Spark loss on #2 sends the alarm off, they will replace it today and test run and call me. I think that was the general concensus here on the forum, but didnt feel comfortable with the replies I got to go out and buy the part just to try it, anyway, I hope its fixed. At least it did its little trick for the dealer, it seams that half the time the dealer cant make the problem happen when you take it in.<br /><br />Thanks everyone for giving it your best.<br /><br />I actually change that box with a used one a freind let me try, but I guess it was bad too, as it acted the same when I changed it.

 

[KCLOST]

Re: Update and more questions Merc 150 (Update)

I'm glad you got it figured out....

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

Update on the update. Now it seems that after they tested everything like they were suppose to do in the first place, that it appears that it is a Stator giving the problem, Not in stock so will be awhile before I get it back. I did suspect a charging problem too. I hope It isnt both.

 

[mellowyellow]

Re: Update and more questions Merc 150 (Update)

chances that your buddy's power pack was also bad<br />and causing the same problem are slim to none IMO.<br />stator seems like the culprit, not the pack...

 

[LubeDude]

Re: Update and more questions Merc 150 (Update)

I,m seeing that now, He said he was surprised that it didnt work and that it may not be the pack. He was evidently right. The stator is cheaper than the pack, but not by much, but the labor may be more.<br /><br />There is always an upside to things like this, Now I have all newly rebuilt carbs, new filters and fuel lines, new fuel pump, new thermostats, new water pump, new plugs, and engine nice and clean. Now I know what I have and where I stand on everthing. Also, I know the engine pretty well.

 

[mellowyellow]

Re: Update and more questions Merc 150 (Update)

you should be good as gold for a long time as<br />long as you don't forget the oil