357 Mag Bravo 4V Reman, Just Installed, 325HP, WORSE then old engine @ 260HP!!! ??

[HT32BSX115]

It's been about 10 years since I set the TB-5 timing on my 454 but I remember it being exactly like described in the following thread for a 4.3 but it's the same for all the TB5 systems. .......and I think yours is 10 degrees but you should check the owners manual for your model(or ask the dealer) to be sure. There should be only one mark on the damper.

I used an "advance" timing light when I did mine. You set it(the light) at the desired advance, set the module in base mode(ground the wire) and move the dist until it lines up the marks.

http://forums.iboats.com/forum/engi...ines-outdrives/602439-setting-timing-on-a-4-3

 

[Fun Times]

do I adjust it to 8 degrees?

Does the flame arrestor sticker say 8 or 10 degrees before top dead center? Personally If 8, I'd go to 9 but if it says 10 then go to 10. Before you put a wrench on the distributor bolt, check it to see if the paint looks distorted....That "may" help tell you if the dealer touched it or not.

THUNDERBOLT V IGNITION SYSTEM

 

[Orbitter]

Perhaps a silly question but, with an advance timing light you would set the timing light to 10 deg advance and with the module in base timing mode, line up the 0 deg mark on the balancer, with the mark on the cover?

I checked timing last night with a non advance type timing light and it was at about 9 deg at about 850 rpm, I then slowed down the idle (Not sure why dealer didn't adjust it but deff to high) and also set timing to 10 deg. There is a mark of yellow paint on the balancer at the 10 deg line.

Also, I did a compression test and plug wire resistance (Since it was easier then tracing all the wires to make sure they were going to the right cylinder).
Cylinder #1 - 170psi
Cylinder #2 - 165psi
Cylinder #3 - 165psi
Cylinder #4 - 170psi
Cylinder #5 - 170psi
Cylinder #6 - 165psi
Cylinder #7 - 165psi
Cylinder #8 - 170psi

Spark Plug Wire Resistance
Cylinder #1 - 20.35k
Cylinder #2 - 12.65k
Cylinder #3 - 17.35k
Cylinder #4 - 17.00k
Cylinder #5 - 15.35k
Cylinder #6 - 15.46k
Cylinder #7 - 12.68k
Cylinder #8 - 19.75k

Spark Plug Colors were different then last time. Brand New Plugs, 1 HR Runtime On Them.
Plug 7 looked exactly as before.
Two of the plugs were noticeably lighter then the rest. I would say, like a very light beige house.
The rest of the plugs however were darker then the other set of plugs I pulled out. I'd say like a mix of cardboard brown and wet dirt brown.
This time I'd say a bit on the dark side.
I do not know the heat range on the new plugs, they were for the old engine and I had them in the boat so I put them in. Could be why they were darker.

Also, the rev limiter does NOT seem to be operational.
I wanted to see if it was at 5k or 5200 rpm etc so I advanced throttle to about 4500 rpm and then blipped the throttle and it went damn close to 6k rpm!

EDIT: The compression test was done with the engine warm.
I also checked manifold temps (within 1 min of turning off the engine) the starboard side was 111-113F and the port side was 100 even from front to back.

 

[HT32BSX115]

Perhaps a silly question but, with an advance timing light you would set the timing light to 10 deg advance and with the module in base timing mode, line up the 0 deg mark on the balancer, with the mark on the cover?

Yes. that's the way I did mine and I don't think mine has but one mark. But the other(old) way works too if you have regular degree graduations.

I checked timing last night with a non advance type timing light and it was at about 9 deg at about 850 rpm, I then slowed down the idle (Not sure why dealer didn't adjust it but deff to high) and also set timing to 10 deg. There is a mark of yellow paint on the balancer at the 10 deg line.

Sounds like the timing is in the "ballpark"...........Sounds like the dealer DID NOT set the timing(or set it wrong) . 850 RPM is way too high.

Spark Plug Wire Resistance
Cylinder #1 - 20.35k
Cylinder #2 - 12.65k
Cylinder #3 - 17.35k
Cylinder #4 - 17.00k
Cylinder #5 - 15.35k
Cylinder #6 - 15.46k
Cylinder #7 - 12.68k
Cylinder #8 - 19.75k

How did you measure? what type of multimeter? Autoranging, direct reading etc? I have never really worried about plug wire resistance but those seem high.

FROM MSD:...............Not sure how relevant this might be..........

[h=1]Spark Plug Wires[/h] If you suspect a spark plug wire to be open causing poor performance, check the resistance of each wire. By checking the resistance of each wire you will determine two things: That there is continuity (not open) and if there is too much resistance in the wire. Use an Ohm Meter and connect the terminals to the spark plug wire terminals. Use care to make sure there is good contact or the readings will be inaccurate. On MSD wires the resistance should be:

Heli-Core Wires (Blue):
150 - 1,200 ohms per foot

8.5mm Super Conductor (Red):
40 - 50 ohms per foot
If you do not know the specification for your wires, measure the resistance of each wire. Remember to divide the length of the wire by 12 to get a "per foot" measurement. If one wire is out of that average spec, it is at fault
Solid Core Wires: You cannot run Solid Core Spark Plug Wires with an MSD Ignition Control. Solid Core wires do not suppress any Electro Magnetic Interference (EMI) which will interfere with electronics or rev limiters on your vehicle. A suppression style or spiral wound spark plug wire MUST be used.

MSD has VERY high voltage ignition systems. At least as high as Mercury TB or maybe even higher. So I would wonder about high resistance wires being either defective or wrong for your engine. Are your plug wires new?

Also, the rev limiter does NOT seem to be operational.
I wanted to see if it was at 5k or 5200 rpm etc so I advanced throttle to about 4500 rpm and then blipped the throttle and it went damn close to 6k rpm!

Not sure I would believe the tach at this point. They are frequently NOT right at the upper scale, blipping the throttle up there causes meter "over-shoot" AND the scale is compressed at the higher RPM's making it very hard to get anything resembling accuracy.

If you still have access to the lower pitch props, I would switch to them and get another tach to see if you can exceed 5200. If that engine has a max RPM of 5200. The rev limiter would be 100-200 RPM higher.

 

[Orbitter]

I used a digital multimeter.

And I assume the plug wires are new as the engine is new. Unless the Reman engines don't come with plug wires...
Or the dealer stole them and put old crappy ones on.

 

[NHGuy]

Hmm ,no compression problem with #7.
Sounds like the wires are OK. But by any chance did you save the wires from the old motor, you could easily stick one on there. What about the cap, does the contact for #7 look poor. Any cracks, any carbon tracking? Try running it in the dark and use a spray bottle to mist the wires and a little near the cap. Electrical "leaks" will visibly jump to ground.
Did you put the distributor in base mode to set/check the timing? Then you're supposed to turn off the engine before un grounding the base timing wire.
You had flooding on the starboard side cylinders with the first carburetor, then the 2nd carburetor has been fouling the rear most cylinder on the same side. Perhaps when the engine is laboring to get on plane and the boat is nose high there is liquid fuel, or too much atomized fuel getting to #7.
You could do the manifold leak test by shooting carb cleaner around the edges of the intake manifold the carb base and any place where shafts and gaskets enter the carb itself.
What carburetor did Merc put on there a Weber WFB? Edelbrock 1409?

 

[Orbitter]

#7 cylinder is on port side. Unless I confused the diagram of the cylinders.
Carb is a Weber.
I did put the ignition module in base mode and took it out when I was done, including cycling the key/turning off the engine. .

 

[achris]

can you see a model number on the carb?

 

[silvert]

Fwiw I have a 23.5' rinker 232 with a 260hp 5.7, bravo 3. Only difference is it's a tbi. It came factory with 26p props. Can pull a skier out of the water instantly with 8 adults in it and a top speed of around 50 gps.
I do not think the props are the issue here.

Id replace wires, cap and rotor. My reman engine was only a long block. I had to use all my existing ignition pieces. I bet yours came the same way.

 

[Orbitter]

Fwiw I have a 23.5' rinker 232 with a 260hp 5.7, bravo 3. Only difference is it's a tbi. It came factory with 26p props. Can pull a skier out of the water instantly with 8 adults in it and a top speed of around 50 gps.
I do not think the props are the issue here.

Id replace wires, cap and rotor. My reman engine was only a long block. I had to use all my existing ignition pieces. I bet yours came the same way.

That's good to hear. Sounds like you have the engine I did have. 5.7 with TBI.
Our engine came complete with everything except the heat exchanger.

Your boat specs are very similar to ours. Yours has a dry weight of 4215 lbs and ours is 5377 lbs.
So when I'm testing mine with just myself on board, it's like yours with 5-6 passengers.

 

[Orbitter]

can you see a model number on the carb?

I think I might be able to make out a model # on the front, bottom right side but it's tough.

I did take some pics of the carb and engine so maybe someone who is familiar will see something glaring back at them.

Other then that, I'm not sure what steps to take. Seems like we may have hit a wall.
I am going to change plug wires & retest in water but not hoping for much.
If it were leaking air in somewhere then when I manually held the choke it would improve and it doesn't so I doubt it's leaking anywhere.
I will replace plug wires, plugs (Again) and cap n rotor but past that I think I'll just take it to a better mechanic for a second opinion.

It would seem to be something out of the ordinary at this point. Faulty ignition module, faulty dizzy etc...
Pretty simple engine and mechanically it seems to pass all the tests.

Any other ideas on what might make it run so whimpy?

Will try to get those parts tomorrow and reply back after testing on the water.

 

[Orbitter]

No Title

Here are some photos. Some of the spark plugs which have about 1hr on them vs the previous photos showing the old spark plugs which had 10hrs on them.

 

[Orbitter]

Is there a way to lean the carb just to test if the mid rpm is to rich? A way just for testing purposes without changing jetting?
It's got a mechanical fuel pump btw and a hard line going to the carb so I can't just pinch the fuel line

 

[Orbitter]

... oops...

 

[Fun Times]

The plug wires should be brand new, if you believe you found a problem with them then the dealer should test and ask Merc for new ones...It shouldn't be on you $$$. It don't really sound like you have a plug wire issue though.

There seemed to be a reason this guy in the following link was wanting to change his rods, jets, or springs and it seems he was on to something with his idea of wanting to change the power curve a little as I believe I've read in the past another type of problem this engine model has had and the carb seemed to be the issue much like you are having. http://www.justanswer.com/boat/7w32o-just-2013-mercruiser-357-mag-bravo-one-4v-engine-sn.html#

^ And yes there is a service manual for this engine believe it or not. https://www.perfprotech.com/mercury...4/0?search=90-861327T01&sortpartnbr=861327T01

Here's your parts catalog for this engine, http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=884715004

You can check out the carb internal differences between the Alpha and Bravo...Also if you read through all the part notes, you'll be able to see where the differences between the two engine models such as the camshaft for example.

 

[Orbitter]

Very helpful! Thank you.

 

[skippy2235]

After seeing those plugs, and seeing temps of only 100 Deg. You are over fueling.
Change jets smaller till exhaust temps get to around 200 - 250 Dec farinheight.
The best way would be to install an O2 sensor and use those readings of 13.5 afr.
But That that is money and time.

 

[Orbitter]

200+ would be way to hot for the manifolds from what I have read.
100-160 depending on incoming water temp is normal.

I wouldn't be surprised if it's running rich though, but by the look of the plugs (Especially the first set with 10hrs on them) they would indicate a lean condition if anything.

The second set of plugs look a little dark but not so much as to cause a performance issue IMO... ?
Typically if you have an issue when asking for Power, it indicates a lean condition.
If you have an issue when cruising, it indicates a rich condition.

Based on the first set of plugs, I assumed lean, but enriching the mixture by manually activating the choke a bit did not improve performance.

Perhaps I could be mistaken... I learn new things everyday and appreciate it when I am corrected as that allows learning to take place!

 

[achris]

The only way to change the mixture (above idle) on those carbs is to open them up and change the jets and metering rods.

 

[NHGuy]

I bet the carb is jetted for the big block motor. See if there are identifiers.