"I did the trolling for a few minutes over the weekend, and the motor is acting up again"
This is exactly what I was afraid the results would be. I did ask you for some information back in November you did not respond? Help us help you...Go back and read my posts please provide all the information I am asking ..including this new info below...
Here is what you need to do..I am assuming never my style ..I am going to stick my neck out on this one...
Vro disconnected fuel mix 50:1 correct? Yes/No
I am sure you seen this engine loads up or run rich when trolling? Yes/No
Remove all your plugs, verify they are champions QL77JC4 gap to .30 snap a picture of the plugs before you clean them, re-install (We may need this info for a comparison later on)
Verify you have the 140 throttle bodies installed (three screws on the butterflies)
If you observed 2 screws STOP do not jet as I recommend below...
Verify your high speed jets are 61d (Stock) Yes/No
Verify both PORT and STARBOARD IDLE jets are (Stock) #28
Intermediate jets are the ones at the very top of each carbs the jets directly below are your idle (do mix these up)
Remove all your intermediates, if jetted stock your PORT's will be #20 and STARBOARD #16
Now here is what I recommend you do REPLACE OR RE-JET all your intermediate's to #16
I am asking you to LEAN out your intermediate mixture.
Note> both your idles and intermediates are indeed "air jets" the rule is larger the jets=more air flow=leaner fuel-mixture. Smaller the jets less air flow richer the mixture.
Note> this rule does NOT apply to your high speed since its regulates fuel flow NOT air.
Run the engine on hose then on the Lake at various speeds etc, You should see a huge change in the way this engine runs, on the hose you will see a increase in idle, adjust if needed.
Take notes you are benchmarking and needs to log everything.
Once back in the yard remove your plugs and carefully label and inspect each plugs, take a picture and post it we need to see if this engine is running lean or just right.
If lean we need to jet up and etc....
An old timer told me this trick it seems to work for me you can try it...for excessive trolling for long periods or distance like I do out the channel, Trim the engine up so all excessive unburnt 2 smoke oil drains forward in the cylinder and is pushed out the exhaust port as you hum along. Its a known fact the Looper's never likes to idle under load period.