'89 150 BlackMax idle/start problem...

R

reyb

Junior Member
I'm hoping someone can shed some light on the idle/start problem I'm having. The symptoms are:

1. Difficult to start. However, I can always get it started by increasing the throttle.

2. Once started it will rarely idle. After around 10 minutes of keeping the rpms up with the
throttle it idles fine.

Some things I've done so far:

1. Cleaned the carbs

2. Rebuilt the fuel pump

3. Changed fuel filters (external and the one on the motor)

Questions I have are:

1. Anyone know what years that the '89 150 BlackMax carbs are interchangeable with?

2. Anyone know how to test the idle stablilizer module?

3. Where's a good source to get a manual? I hear that the Seloc is not a good one.

Thanks,

Rey
 
Throw the idle stabilier module in the garbage (along with the oil injection) and have a good mechanic set the timing on that motor. A good sync and link should help. Bad reeds can also cause starting/idle problems. Check compression of the motor too while your at it, just to be sure. You can find Mercury factory service manuals on ebay for cheap.

Good luck!!
 
Thanks Big. I did read somewhere about just removing the idle stabilizer module. I believe I found it located on the throttle linkage side of the engine near the rear of the engine. It had 3 wires plugged into it in addition to a bunch of wires in a harness coming out of it. I disconnected the 3 and there was no affect on the idle. What would a bad reed valve look like? I don't recall the compression numbers but I do know there were all within a few lbs of each other. I'll check out eBay on the manual...thanks again!
 
2 things i would have a mechanic check but i hope you can find an honest one, good luck on that
1st the carbs might have to be rebuilt
2nd the stator
good luck
if you live in nj go to anglers marine in seabright nj there the best and honest plus they will fix your boat right the first time
 
I've rebuilt the carbs but for it to idle after 10 minutes of warming up leads me to believe something else is going on. Something else is being affected by the heat.

I'm not sure if the carb is good in the first place. Jets have been replaces and from what I read the jets of all 3 carbs might be matched, so that's why I was wondering if I can use other year carbs on this '89.
 
From what I've read, the idle should be around 750 +-. If it idles high, then I might not be able to get it in gear; so I've read.
 
750 to 1000 should be good
those motors have alot of electrical switches and boxes it could be electrical problems
i have a 1988 and i had to change my stator 3 times and the simptoms vary
 
what kind of tach are you using to set the idle rpm, the one in your dash is probably not accurate enough at low rpm, I set the idle rpm usually by ear if i don't have my shop tach handy. I set it high enough where it will idle in gear, but when I pull it out of gear and back in, the boat doesn't lurch and you don't have a big clunk when shifting, try going from fwd to reverse, as long as it stays idling, adn it doesn't shift too harsh, you should be ok
 
steplift20 said:
750 to 1000 should be good
those motors have alot of electrical switches and boxes it could be electrical problems
i have a 1988 and i had to change my stator 3 times and the simptoms vary
Click to expand...

Is it easy to test the stator? If so, can you give the steps on how to do it?
 
spareparts said:
what kind of tach are you using to set the idle rpm, the one in your dash is probably not accurate enough at low rpm, I set the idle rpm usually by ear if i don't have my shop tach handy. I set it high enough where it will idle in gear, but when I pull it out of gear and back in, the boat doesn't lurch and you don't have a big clunk when shifting, try going from fwd to reverse, as long as it stays idling, adn it doesn't shift too harsh, you should be ok
Click to expand...

Yeah, just referencing the tach on the dash. Again, it idles fine after it the motor has warmed up for about 10 minutes. I believe it's around 750 - 1000 and I can shift into gear with pretty smoothly.
 
go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?
 
Hope you don't have the same problem I have. I pulled my hair out trying to find out what was going on with my motor. It was hard to start cold, wouldn't idle until it warmed up real good, would die when put in gear sometimes. I think I found my problem when I noticed a few drops of water on the #3 sparkplug. Pulled the head and found the head gasket had blown and water had been seeping into the cylinder for some time. Long enought o do some serious damage to the water-jacket side of the cylinder. Have cleaned it up real good and am filling in the missing bit of metal with JB Weld and ordering a new head gasket. Hopefully I can fix it. Don't just go pulling your heads though, I broke one and had to EZ it out. Was not fun and sure don't want to pull the other head to examine.
 
spareparts said:
go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?
Click to expand...

About the only thing I've done that you've suggest is to do the compression check. I don't recall the numbers but will do it again. I do remember that all the cylinders were relatively the same. I'll be getting a manual but as of right now I don't know the procedure for doing the other things you suggested.


Hmmm, after replying to Hook's comment could the syncing of the carbs, pulling off the idle stabilizer and adjusting the pickup timing be affected by the motor being warm?

Thanks,

Rey
 
Hooked,

I don't recall seeing any kind of water on the spark plugs. Since my motor seems to idle after it's warm, it makes me wonder what it could be.
 
spareparts said:
go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?
Click to expand...

Rey - Start here. If you are concerned about a blown headgasket . . . the compression test will reveal that . . . also you can see water intrusion by reading the plugs. Water will steam clean them and they will look brand new. Honestly I think you just need to adjust the pickup timing so that it idles. One more question . . . do you have the giant 40 voltage regulator on your motor? Spares is a skilled factory certified Mercury Mechanic with many years of experience . . . consider yourself lucky to get his free advice.
 
"pickup timing" I'll definitely be googling that as I don't know what that refers to. :) I don't know if I have the 40v regulator. Module wise I have the ~3"x5" black box located near the rear or the engine on the throttle linkage side and just above that on top of the engine there is a ~2"x3" module with 2 wires going to it. I'm still trying to locate a Clymers manual locally but if I can't ,then I guess eBay it is. Btw, I appreciate all the input I get on this...thanks so much!

Rey
 
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