New 01 Bayliner 4.3 MC...have a few questions

[beav1]

Hi folks, new user here and brand new boat owner.

Purchased a 2001 Bayliner Capri recently with a 4.3 Mercruiser. We took it out once and it did pretty well, but here is what I am dealing with. Hoping to find some help here.

1. Echoing dry bearing sound - FIXED by replacing the bad gimble bearing.

2. Minor backfiring at higher RPMs (maybe lower RPMs), but only heard them when prop came out of water a couple times. Is this due to instantaneous load loss or is there a real issue? My plan of attach was to replace plugs just in case and also to time the ignition. I've also wondered about the timing advance... Thoughts?


3. I understand that there is a special timing procedure. I have a timing light, but where can I find details on this "special" procedure?

4. I pulled out AC Delco R44T plugs, but the cover on the spark arrestor states AC-MR43LTS. However, the MR plug threads were MUCH deeper than the R44Ts that I pulled out. I was concerned that piston clearance would become an issue.


5. I've tried to find the engine S/N on the engine, but it is not on the spark arrestor cover, nor on the side of the bell housing (unless I missed it). Any other place that I could find the engine S/N?


6. Lastly, would anyone be able to confirm which engine I am dealing with on the Mercury parts list (pic below):


Thanks in advance for any assistance!

 

[wshekar]

I can't help with every question but I have the same engine (likely earlier vintage ). The manual shows AC-MR43LTS, Champion - RS12YC, or NGK-BPR6EFS as spark plug options. I believe you have the wrong spark plugs.

I also see that you have the batwing exhaust manifolds. Most people would suggest replacing the single piece with the 2-piece version. Those manifolds have been known to leak and can cause hydrolocking. 20 years is long enough. I just replaced them in my boat over the winter.

 

[Fun Times]

Something seems out of place with the exhaust system vs the year of the boat being 2001...Can You post a photo of the exhaust manifolds too?

Check just above the engine starter for a Serial Number plate riveted to the engine block...Should look like this if there, https://www.perfprotech.com/blog/articles/mercruiser-serial-numbers

With the black paint being "disturbed" on the distributor hold down bolt, Suggest the at the very least the ignition timing was changed at some point and maybe the Whole engine block too especially if the serial number is missing from the block as seen above. It would be a good idea to check the timing like listed below.

Do the Valve covers have a saying on them?...You'll/We'll need to figure out if the heads are true GM Vortec heads which Mercruiser calls them Gen + to know for sure what spark plugs to use.


V6 and V8 Carbureted Models (Thunderbolt V Ignition)

1. Connect timing light (91-99379 or similar) to No. 1 spark plug wire. Connect power supply leads, if applicable, on light to 12 volt battery. Refer to Specifications – “Engine Rotation and Firing Order” for cylinder numbering and location.
2. Connect a shop tachometer to engine.
3. Using a jumper wire, connect the ignition system timing lead (PUR/WHT wire) to a good engine ground (-). This locks the ignition module into the “Base Timing Mode”.

NOTE: Before starting engine make sure the timing tab and marks on damper are clean. Chalk or white paint on timing marks may help visibility.

4. Start engine and run at normal idle speed. Allow engine to reach normal operating temperature.
5. Aim timing light at timing tab, located on the timing gear cover and crankshaft torsional damper.
6. If adjustment is required, adjust timing by loosening distributor clamp and rotating distributor body as required until timing mark on damper or pulley lines up with the mark on tab specified in “Specifications”. Tighten clamp and recheck location of timing mark.
7. Make sure that the distributor has been tightened. Remove the jumper wire from the timing terminal.
8. Remove jumper wire between the timing lead (PUR/WHT wire) and ground (-).

IMPORTANT: Be sure to disconnect the jumper wire from between the ignition system timing lead and ground (-) before attempting to resume normal operations. If the jumper wire is left in place, the ignition module will operate in the “Base Timing Mode”. This means that the additional timing advance features would not function.

9. Stop engine and remove timing light.

Mercruiser Engine Timing Procedures | PerfProTech.com

Large selection of quality mercruiser parts, marine engines, marine parts, boats parts and accessories, such as Mercuiser engines, exhaust, motors, and other boating supplies and accessories. Find affordable parts for leading brands including Volvo marine parts, Mercury marine parts, Quicksilver...

www.perfprotech.com

 

[wshekar]

The valve covers probably say VORTEC. Better to count the bolts on the intake manifold to know if it is a true vortec head. I suspect yes.

 

[Rick Stephens]

Batwings seem weird in a 2001. I thought they were gone in the mid 80's.

How did you get the prop out of the water? I've never had that happen when I was being sane anyway.

When you hear popping, that is usually a lean condition, unless the timing is way off. Running lean will burn holes in pistons and warp valves. I'd suggest a carburetor rebuild is in your crystal ball.

 

[wshekar]

Batwings seem weird in a 2001. I thought they were gone in the mid 80's.

Negative. I have a 1998 Vortec with batwings. Just replaced them over winter.

 

[Lou C]

I think that Merc used them from 1996-2000 although some sources say till 2001, it is possible to have a 2000 Powertrain in a 2001 boat. There is a conversion using Barr Marine parts to convert over to the 2 piece style.

 

[Lou C]

PS I had OMCs version of the one piece manifolds on my boat and over 15 years of salt water boating I never had a problem with them leaking. I did replace them a couple of times but that’s normal in salt water. I converted mine when I did a top engine overhaul in 2017; by then my last set was due for replacement and they had become NLA long before. I used Barr Marine OMC/Volvo manifolds and V/P parts to make it work.

 

[beav1]

I can't help with every question but I have the same engine (likely earlier vintage ). The manual shows AC-MR43LTS, Champion - RS12YC, or NGK-BPR6EFS as spark plug options. I believe you have the wrong spark plugs.

I also see that you have the batwing exhaust manifolds. Most people would suggest replacing the single piece with the 2-piece version. Those manifolds have been known to leak and can cause hydrolocking. 20 years is long enough. I just replaced them in my boat over the winter.

Thanks for the reply... I did look for the tag in that area before, but I'll double check.
2-piece manifolds will go on my to-do list, thanks!

 

[beav1]

Something seems out of place with the exhaust system vs the year of the boat being 2001...Can You post a photo of the exhaust manifolds too?

Check just above the engine starter for a Serial Number plate riveted to the engine block...Should look like this if there, https://www.perfprotech.com/blog/articles/mercruiser-serial-numbers

With the black paint being "disturbed" on the distributor hold down bolt, Suggest the at the very least the ignition timing was changed at some point and maybe the Whole engine block too especially if the serial number is missing from the block as seen above. It would be a good idea to check the timing like listed below.

Do the Valve covers have a saying on them?...You'll/We'll need to figure out if the heads are true GM Vortec heads which Mercruiser calls them Gen + to know for sure what spark plugs to use.


V6 and V8 Carbureted Models (Thunderbolt V Ignition)

1. Connect timing light (91-99379 or similar) to No. 1 spark plug wire. Connect power supply leads, if applicable, on light to 12 volt battery. Refer to Specifications – “Engine Rotation and Firing Order” for cylinder numbering and location.
2. Connect a shop tachometer to engine.
3. Using a jumper wire, connect the ignition system timing lead (PUR/WHT wire) to a good engine ground (-). This locks the ignition module into the “Base Timing Mode”.

NOTE: Before starting engine make sure the timing tab and marks on damper are clean. Chalk or white paint on timing marks may help visibility.

4. Start engine and run at normal idle speed. Allow engine to reach normal operating temperature.
5. Aim timing light at timing tab, located on the timing gear cover and crankshaft torsional damper.
6. If adjustment is required, adjust timing by loosening distributor clamp and rotating distributor body as required until timing mark on damper or pulley lines up with the mark on tab specified in “Specifications”. Tighten clamp and recheck location of timing mark.
7. Make sure that the distributor has been tightened. Remove the jumper wire from the timing terminal.
8. Remove jumper wire between the timing lead (PUR/WHT wire) and ground (-).

IMPORTANT: Be sure to disconnect the jumper wire from between the ignition system timing lead and ground (-) before attempting to resume normal operations. If the jumper wire is left in place, the ignition module will operate in the “Base Timing Mode”. This means that the additional timing advance features would not function.

9. Stop engine and remove timing light.

Mercruiser Engine Timing Procedures | PerfProTech.com

Large selection of quality mercruiser parts, marine engines, marine parts, boats parts and accessories, such as Mercuiser engines, exhaust, motors, and other boating supplies and accessories. Find affordable parts for leading brands including Volvo marine parts, Mercury marine parts, Quicksilver...

www.perfprotech.com

I thought the very same thing seeing the paint chips on the hold down. Thanks for the timing procedure! I'll take a look closer at the valve covers tomorrow. To be originals, should they say Gen+, Vortex, Or Mercruiser, etc?

 

[beav1]

The valve covers probably say VORTEC. Better to count the bolts on the intake manifold to know if it is a true vortec head. I suspect yes.

If it says Vortex does that make them oem or swapped in from a pickup or something?

 

[beav1]

Batwings seem weird in a 2001. I thought they were gone in the mid 80's.

How did you get the prop out of the water? I've never had that happen when I was being sane anyway.

When you hear popping, that is usually a lean condition, unless the timing is way off. Running lean will burn holes in pistons and warp valves. I'd suggest a carburetor rebuild is in your crystal ball.

Hey Rick, the trim gauge is not working and I brought the prop slightly out of the water a couple times by accident. That's actually when I learned that it was popping.

 

[wshekar]

If it says Vortex does that make them oem or swapped in from a pickup or something?

They are likely OEM. Though, it should end with a "C" and not "X". Everything will be figured out when (or if) you find the serial number. I think the issue was to determine why batwings were used in a 2001 boat (possible replacement engine). As mentioned earlier, the engine is probably a 2000 meaning it falls within the normal production range with everything being original.

 

[beav1]

They are likely OEM. Though, it should end with a "C" and not "X". Everything will be figured out when (or if) you find the serial number. I think the issue was to determine why batwings were used in a 2001 boat (possible replacement engine). As mentioned earlier, the engine is probably a 2000 meaning it falls within the normal production range with everything being original.

I would also like to know if the heads are the correct originals in order to confirm the plugs as well. I'd like to get the MR43LTS ones in there, but not until I know they won't provide a clearance issue for the pistons.

 

[wshekar]

I would also like to know if the heads are the correct originals in order to confirm the plugs as well. I'd like to get the MR43LTS ones in there, but not until I know they won't provide a clearance issue for the pistons.

Count the number of bolts on the intake manifold. 8 bolts means Vortec heads. Serial number should also help confirm.

If you are still uncomfortable, you could place the plug and rotate engine by hand slowly to ensure no clearance issue.

Spark Plugs

I have what I have assumed is a 92 4.3LX mercruiser V6. Serial # shows D828755 or might be D626755 (I'll try to attach a pic). I have been using service manual 7 which says it covers serial number B775130 -F000000. The service manual lists Champion RV15YC4, but other sources for the same...

forums.iboats.com

 

[beav1]

Count the number of bolts on the intake manifold. 8 bolts means Vortec heads. Serial number should also help confirm.

If you are still uncomfortable, you could place the plug and rotate engine by hand slowly to ensure no clearance issue.

Spark Plugs

I have what I have assumed is a 92 4.3LX mercruiser V6. Serial # shows D828755 or might be D626755 (I'll try to attach a pic). I have been using service manual 7 which says it covers serial number B775130 -F000000. The service manual lists Champion RV15YC4, but other sources for the same...

forums.iboats.com

Okay, so the valve covers display "Vortec" and there are 8 bolts securing the intake manifold.
Also, I found the S/N: M029042 Unfortunately, it is not providing any results from the Mercury Parts Catalog??? Therefore, I cannot confirm the plugs.

 

[Fun Times]

Okay, so the valve covers display "Vortec" and there are 8 bolts securing the intake manifold.
Also, I found the S/N: M029042 Unfortunately, it is not providing any results from the Mercury Parts Catalog??? Therefore, I cannot confirm the plugs.
View attachment 339194

The 8 bolts + the serial number help confirm the engine is original and a Gen+(Vortec) and this engine did come original with the 1 piece Exhaust system as seen in the picture....< My misthought as i didn't recall them continuing use until 2000...Thought it was a shorter run...My apologies for the confusion..

Exhaust Manifold Conversion Kit for Mercruiser V6 [BPI58992] - $999.00 : ebasicpower.com, Marine Engine Parts | Fishing Tackle | Basic Power Industries

ebasicpower.com Exhaust Manifold Conversion Kit for Mercruiser V6 [BPI58992] - Manifold Conversion Kit is designed to convert all Single Piece Exhaust Manifolds to the Center Riser Manifolds on V6 4.3L Engines with GM 262 CID Blocks from 1996 to 2000 that have Raw Water Cooling.Kit includes 2...

bpi.ebasicpower.com

Mercruiser 4.3L V6 Exhaust Manifolds | PerfProTech.com
Mercruiser V6 manifold conversion kit 864293A02 807293-C ...

Need to add an 0 in front of the serial number so some systems recognize the number correctly... 0M029042 = MERCRUISER 1 PC W/PS 4.3L ALPHA and uses NGK bpr6efs or AC Delco MR43LTS..., Distributor And Ignition Components

4.3L (GEN +) (2 BBL.) GM 262 V-6 1998 - 0L010044 THRU 0M614999

4.3L (GEN +) (2 BBL.) GM 262 V-6 1998 - 0L010044 THRU 0M614999

www.mercruiserparts.com

MERCRUISER : 4.3L ALPHA/BRAVO (262 CID - GEN +) | PerfProTech.com

Large selection of quality mercruiser parts, marine engines, marine parts, boats parts and accessories, such as Mercuiser engines, exhaust, motors, and other boating supplies and accessories. Find affordable parts for leading brands including Volvo marine parts, Mercury marine parts, Quicksilver...

www.perfprotech.com

 

[wshekar]

I agree with the spark plugs options mentioned above.

As for the 2 piece manifold, just know that you get what you pay for. There are cheap versions that may cause more problems then they are worth. I thought the mercruiser OEM parts were too expensive so I went with BARR. There is plenty of discussion on this forum regarding the topic.

 

[Lou C]

Barr has been good for me. However on any of them it behooves the back yard mechanic to check the flatness of mating surfaces. Use a good straight edge like a level and see how flat they are. Less than .002” variation preferably like .001”.

 

[beav1]

The 8 bolts + the serial number help confirm the engine is original and a Gen+(Vortec) and this engine did come original with the 1 piece Exhaust system as seen in the picture....< My misthought as i didn't recall them continuing use until 2000...Thought it was a shorter run...My apologies for the confusion..

Exhaust Manifold Conversion Kit for Mercruiser V6 [BPI58992] - $999.00 : ebasicpower.com, Marine Engine Parts | Fishing Tackle | Basic Power Industries

ebasicpower.com Exhaust Manifold Conversion Kit for Mercruiser V6 [BPI58992] - Manifold Conversion Kit is designed to convert all Single Piece Exhaust Manifolds to the Center Riser Manifolds on V6 4.3L Engines with GM 262 CID Blocks from 1996 to 2000 that have Raw Water Cooling.Kit includes 2...

bpi.ebasicpower.com

Mercruiser 4.3L V6 Exhaust Manifolds | PerfProTech.com
Mercruiser V6 manifold conversion kit 864293A02 807293-C ...

Need to add an 0 in front of the serial number so some systems recognize the number correctly... 0M029042 = MERCRUISER 1 PC W/PS 4.3L ALPHA and uses NGK bpr6efs or AC Delco MR43LTS..., Distributor And Ignition Components

4.3L (GEN +) (2 BBL.) GM 262 V-6 1998 - 0L010044 THRU 0M614999

4.3L (GEN +) (2 BBL.) GM 262 V-6 1998 - 0L010044 THRU 0M614999

www.mercruiserparts.com

MERCRUISER : 4.3L ALPHA/BRAVO (262 CID - GEN +) | PerfProTech.com

Large selection of quality mercruiser parts, marine engines, marine parts, boats parts and accessories, such as Mercuiser engines, exhaust, motors, and other boating supplies and accessories. Find affordable parts for leading brands including Volvo marine parts, Mercury marine parts, Quicksilver...

www.perfprotech.com

Thank you for the info! I really appreciate all the help that I have received from this forum. I'll be sure to get the right plugs, set timing and work towards getting the 2-piece manifolds soon.

Thanks again!