2008 4.3 TKS

[siocco]

Hi all,
First time poster, thanks in advance for the help. I have a 2008 Mercruiser 4.3 with TKS. Late last year the engine started to miss on heavy acceleration and stumbled a bit. It almost seemed like it was running on 5 instead of 6 cylinders. Took it out for the first time this year and same thing. Was thinking water/fuel seperator, not the case as it was replaced end of last season. Funny thing is one you get up on full speed, the last cylinder will sometimes kick in and it feels great like a burst of speed. seems though that at top speed its kicking in less and less to the one cylinder. Any help is appreciated.
Steve

 

[Dieter]

What did the contents of the fuel filter look like when it came out? look for debris and water in gas.

What is condition of ignition components- cap rotor plugs and wires? any loose wires on dist cap or coil?

crack your fuel cap to see if it goes away, vent on fuel tank can plug and cause fuel

 

[siocco]

Thanks,
I will look for these problem areas on the weekend. I did get a chance to replace the Distributor cap but haven't water tested it yet. It looks like it was original and the boat has 380hours.