2004 115 2 stroke Acceleration

[tapper]

When accelerating the motor goes from low rpm to high very fast while accelerating. When I slowly push down on the throttle it hits about half way and rapidly takes off, unusually fast. I have also had problems on occasion with the motor having no spark, although most of the time it is fine and my lund/mercury dealer can not find a problem. Also when the motor is at very slow idle it is very shaky (more than my 2003 75hp 2 stroke ever does).

Could this be the trigger (located under the flywheel telling the cylinders when to spark???) OR the controls? Any advice/experience?

My lund/Mercury dealer has no answers...

 

[guyjg]

When I slowly push down on the throttle it hits about half way and rapidly takes off, unusually fast.

It's just like my 2003 115 HP. It's a 2+2 engine...it runs on the top 2 cylinders up to 1800 or so RPM and then the bottom 2 just KICK in to action. All 4 cylinders spark continuously. A defective trigger can cause this engine to loose spark from a pair of coils.

 

[galamb]

Agree, it can be a very "abrupt" crossover for those not familiar. But as suggested, I would confirm that the ignition is working properly and that the carbs are set-up correctly. If someone unfamiliar had a go at the carbs they may have replaced them wrong. The jets for 1/2 are very different from the jets on 3/4.

You need an "outboard mechanic" to look at this, not a "Merc tech" who relies on the "computer" to tell him/her what the issue is...