merc 40 2 stroke wont run past 3000 rpms

[mid-river marina]

ive done carb kits, fuel lines and bulb, 4 coils, plugs and wires, fresh battery, upper crank seal (solved the fuel in the test tank problem i had) timing has been checked and rechecked by another tech. still cant get past 3000 rpms. heres the thing, i have THREE mercs doing this to me, a 97 40 hp, and 87 classic 50 and an 89 mariner 100hp. what am i missing?

 

[jimmbo]

They do have one thing in common. Sounds like all three have been incorrectly adjusted/tinkered with, the same way. When you say Timing has been checked? What exactly are you/tech checking? Was the Sync between the Carbs and Spark Timing adjusted/tinkered with?

 

[mid-river marina]

carb sync, no. it hasnt been messed with. on the 97 merc 40 the timing was set at 0 degrees, spec was -2 to +2, so we set it in the middle, the high speed timing? i think- we pulled and grounded plugs, throttle at wot, and set timing while cranking at 30 degrees. thats all we have done, we made almost no adjustment as it was. a local friend suggests that the timing is not advancing at wot. not sure where to go with that

 

[mid-river marina]

now its been suggested that the stator could be bad. guess i'll throw on at it and see

 

[Ksanthony]

You can just test the stator, I also checked and all three of those have the same rectifier. I had the same problem on my 85 115. I disconnected the yellow wires and insulated them and checked the boat out in the water. she ran like a top. might be worth a shot its a free check.

 

[Ksanthony]

throttle closed is initial pick up. throttle at WOT would be giving you max advance pick up. For the most part it sounds like you set it correct, not sure on the numbers. I would say you didn't mention disconnecting the "Black Box" during your timing procedure. Mine had already had it removed by the time I got ahold of it so I am not familiar with those. When it comes to the ignition on these go to www.cdielectronics.com. they have the best trouble shooting guides I have found. For a step by step process to set the timing, or Lync and Sync look that up in other forums on here.