Loss of power

[jw2101]

Ok I have a reman 351 about 50hrs on it. The problem I am having now and always has been a issue is I loose about 400 rpms on top speed and then somtimes it will jus kick in. Somtimes out of the hole can be sluggish and other times not. When I did motor swap I changed to electic ign, coil, new alt, new plugs this weekend, had carb rebuilt, cap rotor, wires. It runs smooth as can be at idle. Revs smooth and powerfull in nuertral. Just somtimes bogs and loss of rpms and then just kicks in. Does it sound like a bad wire.

 

[Viking...]

Re: Loss of power

Do you take on a bit of water during normal operation of the boat?

Is the boat always loaded the same? Same number of people on board? Same amount of gear?

It's amazing how a bit of weight can make a big difference (I use my kids as ballast).

Try to consider all of the variables when you notice a difference in performance.
If you are satisfied that it's not an outside variable, be sure to mention these details to help pinpoint the problem more accurately.

If it is an engine problem, there's three things that have to work perfectly...fuel, electrical, and air.
Some more details will help get us to possible issues.

 

[jw2101]

Re: Loss of power

Do you take on a bit of water during normal operation of the boat?

Is the boat always loaded the same? Same number of people on board? Same amount of gear?

It's amazing how a bit of weight can make a big difference (I use my kids as ballast).

Try to consider all of the variables when you notice a difference in performance.
If you are satisfied that it's not an outside variable, be sure to mention these details to help pinpoint the problem more accurately.

If it is an engine problem, there's three things that have to work perfectly...fuel, electrical, and air.
Some more details will help get us to possible issues.

load or no load power comes and goes. It happened 4 times today.

 

[Viking...]

Re: Loss of power

Electrical:
You mentioned several new parts, and have switched to electronic ignition.
Won't hurt to double check your ignition wires, make sure they're all seated and routed well, no strains or kinks, etc.
A bad wire might still idle ok on a V8, but you would definitely lose some top end.
Try removing one wire at a time when it's idling, you should notice a change for each cylinder. If not, you can then troubleshoot the problem directly - plug/wire/etc.

More things to think about:
Is the fuel fresh?
How old are the fuel filters/separators?
All the hoses connected on the carbs?
Any vacuum hoses come loose?
Is the fuel tank vent clear?

There's more, just need to think them through...some more likely than others.