4.3 Mercuiser Hard Strating when Warm

[easyloader]

The motor starts perfectly when cold, if idling on muffs for twenty minute boat still starts fine. If running it hard for a few minutes the motor cranks real slow then starts up. I have a mp4 but can't attach it.
Any ideas.

 

[dubs283]

Re: 4.3 Mercuiser Hard Strating when Warm

carb or efi??

 

[easyloader]

Re: 4.3 Mercuiser Hard Strating when Warm

efi

 

[dubs283]

Re: 4.3 Mercuiser Hard Strating when Warm

would need to connect scan tool and monitor data items/check for faults

when was the last full tune-up??

 

[easyloader]

Re: 4.3 Mercuiser Hard Strating when Warm

would need to connect scan tool and monitor data items/check for faults

when was the last full tune-up??

I've replaced exhaust manifolds/risers/flappers due water infiltration.
while I was at replaced cap rotor,wires and plugs.
Someone mentioned it could be timing, hydro lock even though oil has no water, or bad compression.
am calling mechanic tomorrow.
what do you think?

 

[dubs283]

Re: 4.3 Mercuiser Hard Strating when Warm

i think a reputable marine mechanic will find the issue

did you check/adjust the timing after the new plugs, cap/rotor, etc...???

hydrolock will not show water in oil, but is possible with a faulty exhaust manifold(s)/gasket(s)

 

[stang32]

Re: 4.3 Mercuiser Hard Strating when Warm

check the timing ,also check to make sure the battery connections are tight, if the engine is hot & there is any voltage drop, the engine will crank slow, stop crank,start

 

[easyloader]

Re: 4.3 Mercuiser Hard Strating when Warm

The mechanic came by today and check the timing which was way off. I'll test it in the water this weekend.
My only concern is the way the mechanic adjusted the timing. All he did was put the timing light on number 1 cyclinder and made the adjustment. Based on forums I've read I thought that you had to put the ECM module in the service mode before adjusting the timing?

 

[dubs283]

Re: 4.3 Mercuiser Hard Strating when Warm

Based on forums I've read I thought that you had to put the ECM module in the service mode before adjusting the timing?

probably, what is the enigne serial number??

 

[easyloader]

Re: 4.3 Mercuiser Hard Strating when Warm

Ol622296

 

[dubs283]

Re: 4.3 Mercuiser Hard Strating when Warm

if it has the thunderbolt 5, you must ground the purple/wht lead when checking/setting timing

thunderbolt 4 is adjusted like a conventional ignition

 

[CaptainMak]

Re: 4.3 Mercuiser Hard Strating when Warm

The mechanic came by today and check the timing which was way off. I'll test it in the water this weekend.
My only concern is the way the mechanic adjusted the timing. All he did was put the timing light on number 1 cyclinder and made the adjustment. Based on forums I've read I thought that you had to put the ECM module in the service mode before adjusting the timing?

This mechanic is reputable, right ?! Knows his stuff ?

 

[easyloader]

Re: 4.3 Mercuiser Hard Strating when Warm

Reputable, but an okay mechanic