Johnson Fastrike going into SLOW mode

[Semmens83]

I have a Johnson Fast Strike 150 HP model J150GLEOM. I have the oil reservoir disconnected and I'm mixing it in the fuel tank manually. I have a fuel/water separator in between the tank and the bulb, and I have a clear fuel filter after the bulb.

Here's my problem:
The motor will run good at 3/4 throttle but at higher RPMs the motor will run good for a while and then for no reason go into SLOW mode. I can back down, shut the motor down, turn it immediately back on, and take off fine with no trouble, so it can't be overheating, right?

I brought it to a mechanic who changed out the power pack and the sender. He didn't find any visible place where the tan wire is grounding out. He is recommending now I change the System Check gauge on the dashboard and that might fix it.

Does this sound right or is he just throwing parts at it now? Any ideas what could be sending this motor into SLOW?

 

[Chris1956]

Re: Johnson Fastrike going into SLOW mode

Are you sure you are going into SLOW mode? That clear fuel filter could be restricting fuel flow, or the tank vent or Antisiphon valve could be restricting fuel flow. This will cause the motor to slow down, as it starves for fuel. If you have the overheat alarm, maybe the cooling system is in need of assistance?

 

[boobie]

Re: Johnson Fastrike going into SLOW mode

Please describe your version of SLOW mode.

 

[Semmens83]

Re: Johnson Fastrike going into SLOW mode

http://www.youtube.com/watch?v=Ua8pD9d5Lqs

This is what it starts doing after I hit about 4500 - 5000 rpms. Not my motor in the video, just one I was able to find.

 

[boobie]

Re: Johnson Fastrike going into SLOW mode

SLOW usually kicks in at 2500 rpm, not 4500-5000 rpm. Sounds like other probs.