Logo
FULL SITE MENU

Milky oil

Tony1999bayliner said:
Spark plugs
Ac-mr43lts. The plugs advance auto gave me was ngk tr5
Click to expand...

Is that what you have in there now?

The "LTS " means extended tip and the gap as specified on your label is .035"

See this is what i mean. Your throwing out non valid information leading other to give you bad advice and information back.

Where in this entire thread did you tell anyone exactly what spark plugs were supposed ro be in this engine vs what you installed?

If you installed R43T which are short thread vs R43lts the you F' up again!
 
Ac is the brand
M means marine grade (stainlees steel)
R means resistor

43 is heat range

T vs LTS is short vs extended
 
Tony1999bayliner said:
Where I’m lost on spark gap it say .035 but online some say in 2007 mercrusier change to .045 on all 3.0 motor.. I’ll probally follow what carb cover says
Click to expand...
Yours is a 1999 correct? Then thats what your gap should be.
There most likely was a ignition type change which needed a larger gap in newer models
 
One word of advice,

If you ever post any questions again.
In your first post copy and paste your engine specification including the year of the boat.

Then 99% of information given will be more acurate vs guessing what you have and asking repeatedly what you have.!!
 
One last thing to note,

Heavy mechanical issue most understand and can give good advice.

Carb, ignition and associated parts are serial number based and change over time.

Most here cannot always know those specifics without at least the serial number.

Many here have tons of experience but most dont have photographic memories to know exactly what any given year/engine/ignition and those associated parts should be. We work on many other models and years from 1970's to current models 4, 6, V6 and V8 models.

Lots of different soecifications to remember
 
that why I’m here for help.. this is the first forum I have ever join for the most part I just pay mechanic to deal with issues .. I’m trying to do repairs myself and learning as much as I can after. Got brave enough to replace headgasket I realized it gives me peace even when it’s costing me headaches I sorta enjoy it.. I know crazy… thanks for all helps and input..
 
Tony1999bayliner said:
that why I’m here for help.. this is the first forum I have ever join for the most part I just pay mechanic to deal with issues .. I’m trying to do repairs myself and learning as much as I can after. Got brave enough to replace headgasket I realized it gives me peace even when it’s costing me headaches I sorta enjoy it.. I know crazy… thanks for all helps and input..
Click to expand...

I am sure we all understand. You are not the first "newbie" or the last.

That is part of the frustration. We have to ask the same questions over and over again due to lack of specific information from the begining.

Also after rereading I am still not clear what spark plugs you installed. You have mixed information. But that should be resolved as the spec is clear on the cover label. Get that sorted out.

Also. Auto spark plugs will not have the "M" in the part number. It is perfectly acceptable to use either in a non salt water, fresh water only enviroment. So buying the less expensive is ok
 
Tony1999bayliner said:
Got info adjusting mercrusier 3.0 vavle adjustment from you tube.. it show cyl1 fire stroke at tdc adjust cyl1 intake and exhaust same time.
Cyl2 intake cyl3 exhaust cyl4 intake rotate 360 and do the rest.. this is where I believe I messed up I rotate 360. Got distracted than I think I rotate it 360 again… my guess that’s the reason why carb backfires at 2000rpm… I will redo it with no distraction this time..
I know dum !!! lol don’t mind if I get lit up on vavle adjusting it’s true big mistake for not remembering
Click to expand...

Tony1999bayliner said:
Spark plugs
Ac-mr43lts. The plugs advance auto gave me was ngk tr5
Click to expand...
Look at the boat's registration- I don't know if other states are the same as Wisconsin, but the engine/drive model and serial numbers are on that. You need to refer to the Mercruiser serial numbers, nothing else. In post #46, I showed the serial number ranges and if yours is actually an '89, it wouldn't have the MR43LTS.

'87-'89 3.0 L uses 59571 and 898264001, shown in the Mercury EPC. That crosses to NGK BPR6FS.

MR-43LTS photo- shows much longer threaded end-

1721660389563.png


MR-43TS photo-

1721660468468.png


NGK- BPR6EFS

1721660552586.png
 
1999 bayliner capri 3.0
Model- mcm 3.0
Displacement 181 cid
Cyl firing order 1342
Ignition timing 2Atdc
Spark plug ac-mr43lts
Spark gap 0.035
Maw wot rpm 4400-4800
Engine rotation left hand
Replaced caps, rotor wires and plugs with ac-mr43lts per carb cover info..
at 2k rpm I don’t hear lots of small popping noise I assume it’s called backfiring anymore but motor shakes.. somthing is off . I believe it’s one of the three that’s off carb a/f mixture,timing or vavle adjustment is off.. what else should I check???
 
Got base timing corrected at 2* Atdc disconnect jump wire and reconnect interrupter switch
Idling around 690-750 rpm timing at 10* Btdc.
Running good..dash tach was so off . Tach shows 700rpm engine sounds loud bought digital tach to check . Original tach shows 750rpm digital tach shows 1950 rpm. Feel stupid never would thought was off..
 
Tony1999bayliner said:
Got base timing corrected at 2* Atdc disconnect jump wire and reconnect interrupter switch
Idling around 690-750 rpm timing at 10* Btdc.
Running good..dash tach was so off . Tach shows 700rpm engine sounds loud bought digital tach to check . Original tach shows 750rpm digital tach shows 1950 rpm. Feel stupid never would thought was off..
Click to expand...
More often than not they are off. Sounds like you are in good shape now .
 
1999 bayliner capri 3.0
Model- mcm 3.0
Displacement 181 cid
Cyl firing order 1342
Ignition timing 2Atdc
Spark plug ac-mr43lts
Spark gap 0.035
Max wot rpm 4400-4800
serial 0L376180


Next issue is throttle shifter..
if shifter forward start at 12:00 and full throttle at 9:00. But when I push shifter forward halfway would be full throttle basically shifter at 10:30 I would be at full throttle.. Is shift cable bad or just needs to be adjusted.. thoughts anyone????
 
Took boat to lake today shift and throttle cables readjusted.. everything seems good.. greatly appreciate everyone here for their guidance, tips and input .. finally got boat running properly will definitely enjoy summer and fall on lake…
 
Back
Top