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460 reman starting issues

Jacobydog

New member
I've recently put a new reman 460 in my boat and I'm having some issues. First some background:

I purchased this boat in 2017. It was my understanding the 460 that was in the boat was a fairly new reman/rebuild, but the boat had sat 6 years without any use. So, we stripped out the old ignition system, and replaced with a pertronix distributor, replaced the cap and rotor, ignition wires, valve covers, put a new carb on (Holley 600), new starter...basically replaced all replaceable components as they looked weathered from sitting so long.

Started that motor up, ran great for about half the summer. Started developing a power/fuel issue. When I would gas the boat, it would run up to about 3800-3900 rpm, then it would drop back down to 3000-3200 rpm. If I ran the boat for awhile, it would start getting fuel/power again. End of the season I had a buddy look at it, he discovered the cam was going bad (we screwed up and didn't prelube the engine before running it). So, that winter we replaced the cam, that spring we broke in the cam, and ran the boat 1 or 2 times, still had same power/fuel issue. Was not able to get the boat in the water the rest of the summer.

This spring, we put the boat in and still had same fuel/power issue. We messed with the set idle screws and that seemed to clear up the problem. I then ran the boat about 3-4 hours, then sucked a valve, doing considerable damage...this brings me to the current reman we have installed.

Got the reman and all components installed (reman was from Summit), put the boat in to fire it up and start cam break in. Boat fired great...only odd thing, was the timing at 1200 rpm was showing about 30*. When I would turn it back to 10* it would start stalling out. So I left the timing advanced and proceeded with break in of the cam and planned to adjust timing after cam was broke in. After 10 minutes the motor started running really rough, sputtering and stalling out, then it died. We could not get it to restart, and if it did restart, it would run like crap than die.

We went and replaced the new spark plugs with newer spark plugs, messed with the timing, checked compression...still nothing.

Yesterday I took the carb to a mechanic to have him look at it. He tipped the carb a little and fuel was dumping out of the front bowl. So he adjusted the float a bit, he also said it looked to him like the float had a scratch and seemed a little heavy. On my way out, the mechanic asked about the PCV valve...I checked and sure enough the valve was bad...we suspect this in conjuction with the adjustment of the set idle screws may have led to the original 460 blowing.

I installed a new pcv valve, and with floats adjusted, went to start it again last night. It seemed a little better, as it would start for a few seconds, sputter, cough and run rough, then die. We tried adjusting the timing several times, but that never really got us anywhere.

I am going to pull the distributor out today and make sure the gear is functioning properly (I read there is a shear pin and that gear could be free spinning???) I also still suspect there may be a fuel issue. Just looking for any other ideas before I get a mechanic and dump a bunch more money into this situation.

thanks for any help/advice
 
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This spring, we put the boat in and still had same fuel/power issue. We messed with the set idle screws and that seemed to clear up the problem. I then ran the boat about 3-4 hours, then sucked a valve, doing considerable damage...this brings me to the current reman we have installed.

Got the reman and all components installed (reman was from Summit), put the boat in to fire it up and start cam break in. Boat fired great...only odd thing, was the timing at 1200 rpm was showing about 30*.
If the advance was showing 30* @ 1,200 RPM, can you imagine what it was doing @ 3,000 RPM?
That is a recipe for Detonation!

Did you install the original 460 harmonic balancer?
If so, did you verify that the outer ring had not slipped on the inner hub?
If the outer ring had slipped, your #1 TDC marks will be incorrect! If it has slipped, it may explain why the 30* @ 1,200 rpm (although not accurate) worked!
When I would turn it back to 10* it would start stalling out. So I left the timing advanced and proceeded with break in of the cam and planned to adjust timing after cam was broke in.
Not good!
Ignition advance must be correct not only for break-in, but also for normal operation.
Incorrect advance can destroy an engine in a heart beat.


After 10 minutes the motor started running really rough, sputtering and stalling out, then it died. We could not get it to restart, and if it did restart, it would run like crap than die. We went and replaced the new spark plugs with newer spark plugs, messed with the timing, checked compression...still nothing.
Do a cylinder pressure test, and if need be, do a cylinder leak-down test.
Also, take a bore-scope and peek into each cylinder and look at the piston decks.



Yesterday I took the carb to a mechanic to have him look at it. He tipped the carb a little and fuel was dumping out of the front bowl. So he adjusted the float a bit, he also said it looked to him like the float had a scratch and seemed a little heavy. On my way out, the mechanic asked about the PCV valve...I checked and sure enough the valve was bad...we suspect this in conjuction with the adjustment of the set idle screws may have led to the original 460 blowing.

I installed a new pcv valve, and with floats adjusted, went to start it again last night. It seemed a little better, as it would start for a few seconds, sputter, cough and run rough, then die. We tried adjusting the timing several times, but that never really got us anywhere.
Correct gasoline Marine engine ignition advance is extremely critical, and is NOT something to guess at.

I am going to pull the distributor out today and make sure the gear is functioning properly (I read there is a shear pin and that gear could be free spinning???)
If the driven gear shear pin has broken, you would not have any ignition nor oil pressure.


My suggestions:

......Perform the PPS procedure and verify #1 TDC markings.
......Verify the ignition advance.... not only BASE advance, but also the progressive and total advance as per your OEM specs.
......Perform a cylinder pressure test (aka compression test). If using a gauge with an extension hose, the pressure will be accumulative, so you will need to run each cylinder through at least 3 compression cycles.
......If the above shows low or erratic readings, perform a cylinder leak-down test.



 
When you pull out the distributor today, see if it makes a funny noise as you throw it right in the garbage can.

Pertronix would be my last choice in an ignition system. Too many issues like yours.

See if you can find a good ole points distributor for testing purposes to eliminate the ignition system.
 
When you pull out the distributor today, see if it makes a funny noise as you throw it right in the garbage can.

Pertronix would be my last choice in an ignition system. Too many issues like yours.

See if you can find a good ole points distributor for testing purposes to eliminate the ignition system.


Chris, I had to laugh at your first sentence. I agree.... Pertronix would be my last choice as well.
 
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Yes, we used the original Harmonic balancer. When I bring #1to TDC the pointer on timing chain cover is pointing to zero. Could balancer still be issue?

compression test was not erratic. Did 3-4 roatations to build pressure, and it jumped up proper. All cylinders were between 120-135.

PPS rest?

Thank you.
 
When you pull out the distributor today, see if it makes a funny noise as you throw it right in the garbage can.

Pertronix would be my last choice in an ignition system. Too many issues like yours.

See if you can find a good ole points distributor for testing purposes to eliminate the ignition system.


Good to know. What are issues with the pertronix? I know several jet boats running this distributor in their 460’s
 
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Yes, we used the original Harmonic balancer. When I bring #1 to TDC the pointer on timing chain cover is pointing to zero. Could balancer still be issue?
If the harmonic balancer's outer ring has slipped on the inner hub.... yes.
In order to verify, you'll need to perform a PPS procedure. (positive piston stop)
This involves using a tool (in the spark plug port) that gently stops the piston at an equal distance (in degrees) on either side of theoretical TDC.
You will rig up a temporary wire pointer.
I prefer to stop the piston at 30 +/- degrees, rather than 10, 15 or 20 (30 +/- gives us more accuracy)
When an equal distance is achieved (this can be 27*, 31*, 26*, 33* etc... as long as they are equal), and when your temporary pointer shows equal distance (in either direction of rotation), the PPS tool is removed.

You will then carefully rotate the crankshaft until your degree wheel's reading reaches the ZERO marking.
Now you will be able to verify the OEM TDC marks against YOUR TRUE TDC marks.
Make new marks as needed.

Once True TDC is established, stake (mark) the balancer outer ring and inner hub so that you will be able to see if it slips further in the future.




PPS rest?
Not following you on that one!

Thank you.

Good to know. What are issues with the pertronix? I know several jet boats running this distributor in their 460’s
One major issue is the small diameter magnet embedded plastic triggering wheel.
The diameter is very small, the magnets are cast into the plastic, lending itself to errors.
Pertronix themselves have admitted to errors of 1 to 1.5 degrees.
1 to 1.5 degrees at the distributor equals 2 to 3 degrees at the crankshaft.

While not all cylinders will be 2 to 3 degrees off..... several may be!
No matter how this is sliced..... it's not good!
 
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It turns out this reman has valves sticking open.

If any of the valves are sticking and/or are not fully closing, it would not explain the following.

Got the reman and all components installed (reman was from Summit), put the boat in to fire it up and start cam break in. Boat fired great...only odd thing, was the timing at 1200 rpm was showing about 30*.



.
 
I suspect there was either operator error with the timing light, or there was more wrong internally

we eliminated every exterior possibility. Mechanic determined faulty internal workings. Motor is being replaced via warranty.

Thank you for the input, it’s much appreciated
 
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