idle stabilizer?

H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
hello, I am running into a problem so I'll start from the top.I have a bad switch box went to go change it and a wire crumbled in my fingers so I take it to boat store and they look it up as part number 87076a 4 but when I look it up that part mounts in different spot on motor and looks different! my parts manual says it mounts in 2 places and 1 is on top of motor were mine is mounted so I'm just confused of what part I need.1984 mariner 150hp magnum! thanks
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

s.n.6637656 ...also the parts manual I have says 3 options it looks as if I have a low speed/highspeed spark advance but don't give any part number of that is the part! thanks
 
C

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: idle stabilizer?

That s/n comes up as:

MARINER - (150MG H.P. (1985 ))
Serial No: 06637656 Model No: 7150765

The parts list I gave you in post # 2 is the correct one for model 7150765

Service Manual P/N: 90-976583

Parts Manual P/N: 90-818855 Is this the number of your parts manual?

From the condensed version of the Clymer manual, page 215:

Models 150 Magnum 11 and 200 hp are equipped wtth a low speed/high speed
spark advance module or low speed/high speed/spark advance/excessive rpm spark retard module in place of Idle stabiiizer.

Here is a copy of that condensed version. Download it soonest to your computer as the link is short lived.

Small Engine Repair Reference Center Home: MARINER - MARINER 135, 150, 150 MAGNUM, 150 MAGNUM II, 175 AND 200 HP.

Gerry
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

thank you for all your help! 1 last question on page 216 of downloaded service manual the last one with 3 mounting holes and 3 wires its the one I need ! I guess they all 3 have same part number?
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

also I have read on other forums that guys have discarded this hole spark advance(idle stabilizer) and changed timing? is this something safely done?
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: idle stabilizer?

Highly recommended to remove the idle stabilizer as when they go bad and increase timing beyond spec, rods have a nasty habit of coming out the side of the engine block.
 
C

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: idle stabilizer?

You say in post #5 that you need the one with the three mounting holes as seen on page 216, yet that one, p/n 87086A10 is not listed for your engine model 7150765

87076A10 Idle Speed Control 1995 Mercury 150 XL 2 0L | eBay

87076A4 is the one that is listed for your engine model 7150765

87076A 4 Idle Speed Control Assembly 115 Mercury 115 HP 6 Cyl SN 65242XX | eBay

If you go to boats dot net and enter each p/n it will take you to a page for the part and show a compatibility list on the lower part of the page. If you enter Ctrl and F, you will be able to type in the engine model number and it will highlight it if it is applicable.

Gerry
 
W

wired247

Lieutenant Commander
Joined
Oct 8, 2011
Messages
1,557
Re: idle stabilizer?

hotrodchard said:
also I have read on other forums that guys have discarded this hole spark advance(idle stabilizer) and changed timing? is this something safely done?
Click to expand...


Yes. take it off. Set the WOT timing to spec and call it good. The stabilizer doesnt do much and its a potential failure point. Mine doesnt miss it or the rev limiter.
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

the wot spec?so j need to change the timning? What degrees if you know? and how would I go about doing that? ....... sorry there are so many questions just want to make sure I understand before tackling this! thanks
 
L

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: idle stabilizer?

When working the idle stabilizer is suppost to keep the idle at the same RPM regardless of load and it does it by advancing and retarding the spark advance. Remove the module and set the max timing at regular timing specs and your fine.
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

ok I took off the stabilizer off and set timing per manual 11 degrees atdc and 22 degrees btdc boat sounded wonderful with ears on! took to river and once in idle was rough and it spit and sputter just wouldn't go! I now have no clue what to do
 
Last edited:
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: idle stabilizer?

Idle speed should be adjusted IN the water with idle timing, usually in the range 4 - 6 ATDC.

Momentarily 'touch' the choke/enrichment, if idle speeds and smooths greatly it may be time to clean the fuel system.
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

while at idle I'm gear forward I touched the choke and motor died as soon as I pushed it
 
L

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: idle stabilizer?

Don't be concerned with idle timing half the time it don't work, put the engine in the water and adjust the idle mixture for idle then adjust the idle speed up just enough to idle in gear, then readjust the idle mix on each carb, I like to start at the top and redo the mixture setting at least 2 times then slow the idle speed down where the engine idles in gear and do the mixtures 1 more time.
 
H

hotrodchard

Cadet
Joined
Mar 10, 2013
Messages
20
Re: idle stabilizer?

I read on a different forum someone was having similar issues and there reeds ended up being bad! anybody think that's my issue?
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: idle stabilizer?

11 degrees ATDC is way late, put a half that back in then put the light back in the toolbox, then add/remove timing to get the idle right.
 
You must log in or register to reply here.
Top