When you guys have the motor dynoed, this might be a dumb question, but, is the motor in the boat. I could pull the motor and have it dynoed but I would have to pull the fuel system and ignition for an accurate tune. If not there would be too many variables once the motor is back in the boat. There is nobody in the area that I know of with a propshaft dyno big enough.

Thanks for the input

Jason

Where are all the veriables? Use the same ign system and fuel system from the boat.

The only veriable is the exhaust if you don't use your exhaust.

Prop shaft dynos do exsist.

A number of things can keep you from turning the RPM's. How does engine run up to 4300?

In my boat after installed, I could rip the prop loose while on plane around 2500 rpm, motor would rap to 4500 & not go any further. After much work, turned out problem was MSD box. Changed out box & motor would then run up to 6,000.

If this is new setup problem could be cam, exhaust, heads, or ??

The boat comes out of the hole a bit slow 1.36 gears and 30" bravo 4 blade(stock). Midrange is pretty strong. The boat accells pretty hard then nothin. From about 3/4 throttle to WOT the motor does nothing more. I will have to look up all the motor specs to give a more clear pic as to what I have going on. I can tell you this, the motor was rebuilt after a valve seat dropped #8 now it is .030 over SRP pistons BRODIX heads new cam the smallest pulley they make for the M1. All new fuel sys. cartech FMU and stock ignition. I'll get the details of the cam dur lobe sep etc. along with piston info.
Thanks for the reply

Jason

Crank it up, pull the throttle back and turn the key off, check the plugs. If everything looks good, you might want to try a smaller prop.

the plugs looked ok I did do this last year. I'm hoping to make some more progress this week weather looks good for a couple of days Thanks for the reply
I went up to BBlades and tried a 28" stock Bravo 1 see above

Does your fuel pressure rise and stay constant throughout the run?

Maybe your fuel plumbing is the issue. I run my main fuel line to an SX regulator then take the return from that to the FMU. The output of the FMU returns back to a T fitting at the inlet of the fuel pump.

Not trying to hijack this thread, but I am in the middle of tuning a (kinda) similar setup. Maybe we can help each other...

My problem seems to be too much fuel.

I am running a spanking new 454MAG with Procharger M1-sc. I have plumbed sx pump through two regulators like some others on this board. I have installed innovate afr meter, and had Crockett re-map ecu.

I have had to back regulator completely out (25 psi) to even be able to get on plane, and am still running 10.8-11.2 or so AFR at midrange rpm. I have had to unplug the boost reference on both regulators to even get past 3000 rpm due to going over rich and bogging down.

I am thinking the ECU is programmed to fat (maybe duty cycle or something) …

What do you guys think?

Any idea what your timing advance is at mid-range and WOT?

My base fuel pressure is 42psi and I'm around 13.2 at idle. 11.2 at your midrange seems a bit rich. A couple degrees timing can make a world of difference.

Your base pressure seems to high if you are using a boost referenced fmu. I fueled my last motor to death. I'm getting "in boat" tuning this time. It's the only way to go if you don't dyno it. Out of town remapping is a shot in the dark at best!

Mine was tuned in the boat. I needed to run that much base to get enough up top under boost. I'm golden.

Base press is about 40psi into boost about 60 psi. My fuel system is set up like this.... Two fuel tanks into H20 sep fuel filter out to areomotive fuel pump -10 line to the stock fuel rail.The stock regulator is still installed at the front of the rail. The return out of the rail into a cartech FMU -8 line. Then out of the FMU to a Y to return fuel to both tanks.

the anti siphon valves are in the fitting that your fuel line hooks to at the tank it might be a elbow or maybe straight. pull the hose off and unscrew the fitting from the tank and see if there is a check valve in it . if so the hole is only a 1/4 inch and has to lift the ball off the seat as well.

So you have ECM tuning capabilities?
You have the mechanical ability to swap injectors?

Why in the world would you be still running a FMU? This is not 1985. 14.5:1afr that motor is a ticking time bomb. Also at 11:1 at low rpm and no boost you are just putting fuel into the crank case. Wow!

What color is OK ? how much boost are you seeing? What throttle body are you running?

Thats whats fundimentaly wrong with procharger. Tuning the AFR by running the engine to different rpms and then shuting off and looking at the plugs. Thats seems so rediculess.

Using the old ati regulator my plugs looked perfect but I was adding a QT. of gas to the Crankcase everytime I went out.
I think it normally takes 2-3 engines to figure out a procharger, Just ask me Jerry and Smitty!

Sometimes you have to work with what's available. Add a wideband 02 sensor and run some data logs, add an aftermarket ECU, adjust whatever you want. Either way you'll probably want to varify AFRs and timing with plug readings.

The plugs were brownish tan. I am seeing 5lbs off boost and the stock TB. I feel I should get an AFR gauge/sensor to more clearly see what is going on.

Jerry
I just pulled the fuel lines off at the tank. no anti siphon valves.

Kennyo
This is my second motor. The first one died before I had a chance to dig into this. I'd love to get this resolved 80 MPH is just not cutting it. My last boat ran 100+ w/an OB.

Thanks again to all for the input

A 30 pitch prop and 1.36 drive is alot to pull,if your afr's are good at 60 psi (seems kinda low for a procharged motor) then a smaller prop is in order,Smitty

Smitty
I felt that way myself so I did travel up to BBLADES and ran a 28 stock BRAVO1. I just lost MPH same RPM. This made me a bit more confused. I have not tried anything smaller. I'm trying to get a AFR today then take the boat out, 70deg today. I will then post fresh #'s as to what the boat is doing.

Thank you

Jason

Where do you install the 02 hole to get the AFR on a manifold style wet exhaust?

Best place is on the riser just above the manifold, before the water is introduced.

Thanks, but unfortunately I'm still a little confused. On my revolution exhaust, does that area still have a waterjacket? If it does, what is the process to get the hole without leaks. I'm not completely familiar with the 02 devices, but I had thought that you weld on the threads, and drill a hole into the exhaust.??

Yes, there is a bung that is welded into the riser. Once the bung is installed, the O2 sensor simply screws into the bung.
I'm not familiar with with your particular exhaust. Maybe someone else can chime in.

Hopefully I do this right...

I just made this the other day and it seems to be working well...

Attachment 337121

I then found another made by someone else on this board, it looks very similar (I like this better actually).....

Attachment 337122Attachment 337123

If you have the revolution, someone else on here installed right in the side of the riser by drilling a 1.5 in. hole in the side and then welding if back up. They then drilled and tapped for the sensor (18mm x 1.5 by the way) It looked pretty slick also.

This seems to me to mean that something is stopping the RPM's , maybe rev limiter set wrong? Can you rev past 4300 with engine in neutral?

With old motor were you running the 1.36 gears and 30" prop. If not what were you running? Had RPM problem on old motor also?

What do you have plugs gaped at? Are you are at 5lbs of boost at 4200 rpms when it falls flat?

Plugs are set to the factory gap. Yes I am @ 5lbs of boost when the motor flattens out.

I installed an AFR gauge and ran the boat today. from idle 11.2:1 to WOT 10:1 The motor is only running about 125deg. (Cold Start Mode?) base fuel press 38 psi WOT 60 psi. What is an ideal AFR?

That is pretty rich at WOT. Should be around 11.5 - 11.9

If gauge is correct you are rich all the way around. I do not remember exactly how I have my ECM set up but I think I start out around 13.1 & then at high boost (over 5) it goes to around 11.5. I feel that my 11.5 is rich but rather have rich at boost I am running to keep the detonation monster away.

I do not know much about your ecm setup but I have base fuel pressure at 43 wtih engine off. My boost refrence pressure regulator keeps the pressure difference with the intake at 43, ie idle aprox 40, 10 lbs of boost = 53 psi

Do a search on AFR on OSO. There have been some good threads in the last 2 or 3 years as to what is good numbers based on RPM and boost with posts coming from some good engine builders.

It seems the harder I run the boat the richer it gets. IT seems that when its looking for more air it cant get it. I tried to run the boat (@ slower speeds) with the hatch open. The AFR leaned out to around 12.7 @ 2000 RPM. I am going to install larger vents and thought of installing a bilge blower sucking air into the engine bay. I also need to verify timing. If I'm not mistaken I'm only at 8* base (set it last year and don't remember) If this is the case I have set up my own rev limiter. I will post after I get the run the boat again. I feel I am now making progress with this and a big thanks to all who have posted givin me some direction. It's been a great learning experience.

8* base timing should stay. However, your total advance will be dictated by the ECU. It would be interesting to get a scan from the mefi during a run and see what bpw, timing, etc are set at. For $200, you can buy the mefiscan software to tell you these things. Otherwise, my opinion is that you're shooting yourself in the foot.

Here is my two cents:


Set up the motor on a dyno.

Put it in the boat and re-check the tune using wideband O2 sensors and go up in 200 rpm increments.

Sounds like your injectors are too small. I have found a set of small bodied injectors that will work in a Merc motor as long as the fuel pump delivers the fuel. They are 65 lb per hour Siemens and have been flowed by Mark at Precision marine. Also a customer of Marks bought these injectors and made an additional 30 plus HP due to the ability to accurately deliver more fuel at a lower PSI.

I was just reading an article where it was stated if the wrong springs were installed they would start to float & limit RPM. After reading this made me think of your problem. Sure you got correct valve springs with this new cam?

Just reading the thread, and seeing that even though you went to a smaller prop, and the the speed decreased, you were still only able to turn 4300 rpm's, this is where I would look. Even though you are rich at wot, you would think the motor would still pull some more rpm's.



Darrell.

I have the Brodix Race Rite BB-R heads, I do not know which valve springs I have. I will give Competition Products a call on Monday to verify which springs. I looked at my paperwork and it does not list. The choices were 140LB or 240lb closed and 400LB or 550LB open.

Warlock,lets sum things up
1.-your boat runs 4300 28 or 30 pitch at about 80 mph,loses 5 mph with 28 pitch.
question-does it free rev to rev limiter at 5300?
2. your afr's are as low as 10-1?
Q- At what rpm do you start seeing 10-1?
3. Turbo jack mentions valve springs BUT-you
would have to have some waaay off to only rev 4300 rpm's
4. Your motor is running 150 degrees-
Plenty hot for a procharger,in fact most run 100 to 120 but either require a "signal conditioner" or ecm re-programming to get it out of warm up enrichment.
Your fuel pressure at 60 psi at wot is on the low side compared to most procharged motors but your afr's at 10-1 tell me its too rich. What heat range plug are you running? Being your afr's are rich all the way acrossed the board I would back the boost referencing regulator off and primary reg until you see more like 13-1 light cruising,12-5-1 hard cruising (0vac-o boost) and 11.5-1 under boost. Usually if the programming is right your base timing at 10 degrees with a mefi will give you about 34 at wot but you probably have something in your programming pulling timing back under boost also. To really get this to run correctly your going to have to see how your ecm is programmed and the best way to do it would be on the dyno backed up by some on the water fine tuning,I know this isn't what you want to hear,try lowering the fuel pressure and watch your afr's CAREFULLY,check all your plugs too,maybe you have a couple fouled out,around 10-1 they will start loading up,Smitty

Even at 8 degrees base you should still have enough total timing unless your programming is set to pull out too much under boost,I had a ecm once that pulled 1.5 degrees out for every pound of boost (8 base plus 24 =32-6 psi x 1.5=23 total,you will want to verify this isn't what you have going on,its hard to do unless you drive it with a mefi tuning program with a tuner watching the computer,or data logging or on a dyno. You need to make sure your ecm is set up for your map sensor also (ie-2 bar map sensor with 1 bar program or vice versa),Smitty

contact Ben at www.mefituning.com he'll pull the program and send you a printout for about $75.00. This will give you a base on the ECU. Quick turn around too!

When you give motor more free air are we still at 4300?

You may have stated the before, but have you replaced coil, dist. cap, and wires? Have you replaced plugs?

Have you run a compression test since rebuilding? I do not think even if you have something bad here your RPMs will be exactly the same with two different pitch props. Just grasping for straws.

If you do not have a degreed ballancer, make some marks on it aprox 10 degrees apart. Then take timing light and run engine up, what is timming doing? This will give you some idea what timing is doing.