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Are my props causing all my problems?

T

TTuck003

New member
Hello,
Terry Here. Just got back from another failed attempt at running this boat. Looking for some help or suggestions.

1st Symptom:

Can’t get it to plane. Bogging down and popping at the carb.

Fuel system:
Holley 2300 2bbl fresh rebuild and cleaning, fresh fuel, new fuel pump, fuel/water separator. Fuel pressure at 5psi at the carb. Cleaned the fuel tank. New plugs.

2nd symptom: getting stuck in gear

New gear oil. Old gear oil small amount of metal on magnet. New dog and shifter thing and seal. Pressure tested good.

It did get hot, replaced the sea pump impeller, staying under 175 degrees now.

Has bad prop from previous owner. I know better…idle great, when 1st start. Starts running rough when warms up. Shudders intermittently. Bogging and vibrations under load. Got it up to plane WOT then it gave up and died. Restarted, but was obviously flooded.

Would out of shape props be the only cause to all of these problems?

Any help here guys is greatly appreciated!
 
TTuck003 said:
Hello,
Terry Here. Just got back from another failed attempt at running this boat. Looking for some help or suggestions.

1st Symptom:

Can’t get it to plane. Bogging down and popping at the carb.

Fuel system:
Holley 2300 2bbl fresh rebuild and cleaning, fresh fuel, new fuel pump, fuel/water separator. Fuel pressure at 5psi at the carb. Cleaned the fuel tank. New plugs.

2nd symptom: getting stuck in gear

New gear oil. Old gear oil small amount of metal on magnet. New dog and shifter thing and seal. Pressure tested good.

It did get hot, replaced the sea pump impeller, staying under 175 degrees now.

Has bad prop from previous owner. I know better…idle great, when 1st start. Starts running rough when warms up. Shudders intermittently. Bogging and vibrations under load. Got it up to plane WOT then it gave up and died. Restarted, but was obviously flooded.

Would out of shape props be the only cause to all of these problems?

Any help here guys is greatly appreciated!
Click to expand...
i would blame the vibrations on the props, but the rest of it sound like tune up and run ability issues.

Since it got hot do you still have good compression and ruled out a head gasket?

I would check the compression, look over ignition components including checking timing and consider a carb rebuild
 
Dieter said:
i would blame the vibrations on the props, but the rest of it sound like tune up and run ability issues.

Since it got hot do you still have good compression and ruled out a head gasket?

I would check the compression, look over ignition components including checking timing and consider a carb rebuild
Click to expand...
Thank you. I’ll get back to you after I check compression and ignition parts. Just put a Holley carb kit in it. It idles and revs great until it’s put under a load.

Again, thank you for your suggestions.
 
reving in N really doesn't tell you much....under load is where the rubber meets the pavement.

I'd also suggest checking the timing as well as making sure it advancing with RPM...

may also want to verify fuel pressure is stable while running...and that the anti-syphon valve is clear...
 
makomark said:
reving in N really doesn't tell you much....under load is where the rubber meets the pavement.

I'd also suggest checking the timing as well as making sure it advancing with RPM...

may also want to verify fuel pressure is stable while running...and that the anti-syphon valve is clear...
Click to expand...
x2 on checking advance is coming in
 
MOTOR READS 388 hrs.

All new spark plugs last year.

Spark plug report. #2 too clean, doesn’t look like it’s burning at all. #4 covered in carbon. All others healthy burn. Ohmed them and all checked out.

One questionable spark plug wire…#4 ohmed out at 10.84. All others were 8 or below.

Coil resistance between the two outside posts 0.00 the inner coil 10.48…bad coil? Coil looks to be OEM.

Cap and rotor look good replaced them last year.

Distributor is factory. Can I put a new HEI with an ICM on this engine or should I stick with mechanical advance with points?

With the info and symptoms I’ve provided, does anyone think this could be a head gasket leak? I have a scope. What should I be looking for or where should I go from here?
 
On your measurements, numbers with UNITS, go a long way to conveying the whole story...

if its running, the coil is not likely to be the problem.

"HEI with an ICM" is vague. Unless you use the boat a lot, you'll be better off with the factory setup, assuming its working.

Know how the ignition timing is behaving is key to getting reasonable performance out of any gasoline engine.

a compression test would be a good next step with a intake manifold vacuum test right behind it...
 
makomark said:
On your measurements, numbers with UNITS, go a long way to conveying the whole story...

if its running, the coil is not likely to be the problem.

"HEI with an ICM" is vague. Unless you use the boat a lot, you'll be better off with the factory setup, assuming its working.

Know how the ignition timing is behaving is key to getting reasonable performance out of any gasoline engine.

a compression test would be a good next step with a intake manifold vacuum test right behind it...
Click to expand...
Ok. Thank you. I’ve done a compression test, numbers at the bottom, but haven’t even thought of a manifold vacuum test. I assume the manifold should hold vacuum correct?

Cylinders 1,2,3 - 135
5,6 - 130
4,7,8 - 120
 
not really, its done with the engine running and assesses the performance of the engine using a gauge connected to the intake.
 
ok fellas. I have an update.

I've found the coil and the ignition control module inside the distributor to be bad. The distributor is mechanical advance. I replace with pertronix and set the timing to 8 degrees BTDC. No more hard to start symptoms and no more missing or stumble.

Also, I took another look at the upper gear box and found that I had mixed up upper and lower gears and shims. I removed, cleaned, checked for damage and replaced them correctly. The reverse gear had gotten hot and the gear and bearing had worked itself out just slightly, preventing me from getting the proper clearance between the bearing and the top torque nut. I put it on the press and was able to get it to bottom out. I torqued the nut and success. Got .008.

It's been raining here a ton in Texas and as soon as it lets up I'll go test it.

I want to thank all of you for your insight and help through this process.

Terry T.
USMC/USA
 
I have one more question...

I don't see anywhere to hook up my vacuum gauge to the intake other than a plug where I believe I could install a port on the intake. Is that what I need to do and if so, is there a specific port to install?

Thanks
 
TTuck003 said:
I have one more question...

I don't see anywhere to hook up my vacuum gauge to the intake other than a plug where I believe I could install a port on the intake. Is that what I need to do and if so, is there a specific port to install?

Thanks
Click to expand...
Yes b have to take a plug out to hook up a vacuum gauge, marine applications don’t use vacuum advance or other vacuum powered accessories so typically no hook ups
 
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