extremly rough running

[jamepc]

Finally got to start up the Islandia after over a year or so of sitting but it runs extremely rough and rich idle as per the video.
It will actually runs smooth for about 10 seconds on a cold start, then start this behavior.
Has clean premixed fuel, all lines flushed, new filter, VST cleaned, and has a psi of about 35.
Thanks for any help.
James
PS It's a Merc 240 SN OE382923

[video=youtube;pS3CuW96f_k]https://www.youtube.com/watch?v=pS3CuW96f_k&feature=youtu.be[/video]

 

[jamepc]

Dr Honda,
Do you happen to have any ideas what it could be?
Also, I looked up the procedure to test the TPS and see it requires the use of special lead assembly (91-816085) that goes between the EFI harness connector and TPS connector then gets plugged into a volt meter. Is there a way to read the voltage and set the TPS without the special harness?
Thanks again,
James

 

[Tim75]

TPS check

Dr Honda,
Do you happen to have any ideas what it could be?
Also, I looked up the procedure to test the TPS and see it requires the use of special lead assembly (91-816085) that goes between the EFI harness connector and TPS connector then gets plugged into a volt meter. Is there a way to read the voltage and set the TPS without the special harness?
Thanks again,
James

The harness was about $15 when I bought mine from BAM Marine.com in FL. Well worth the cost.
However, it can be done without the harness. There are several threads on how to do it.
Remember to unplug the sensor on port-side head. Detailed procedure in service book.

 

[Dr Honda]

OK.............


1) You may be overheating the engine. The flush port doesn't get enough water into the engine to keep it cool. DO NOT run it long on the hose.

2) It's a 2-stroke. It's going to smoke, and run rough until you get a load on it. (especially after sitting)

3) Are the sparkplugs old? They could be fouled.

4) If it was OK when you parked it... chances are... it will be fine once you run it.




Anyway... Like I say all the time... RUNNING IT ON THE TRAILER TELLS YOU NOTHING !!! So... go put it in the water, and take it for a ride, then if there is still a problem, we can work though it.