Losing full throttle

[skiatook_bu]

I have had a problem losing full throttle over the past few weeks. (2003 VLX Monsoon) It happens with perfect pass on or off. I removed the Perfect pass stepping motor and opened it. everything looked Ok. Perfect pass tightens up when turning key on, but I will randomly get slack in the cable and can only get about 1/2 throttle. It happens with perfect pass on randomly pulling someone I can't get over 15MPH, other times it is fine, and it happens with it off cruising, I'll have full throttle one time and then later I can only get to around 35MPH

Any ideas?

[Ndawg12]

Have you checked the linkage at the shifter?

[85 Barefoot]

have you ever replaced your throttle return spring? How long have you had ppass installed?

[Green_Giant]

I've had the allen head set screw back out ever so slightly on the stepper motor knob with similar results, may be worthy of a check / replace if it's the least bit gnarled.

[skiatook_bu]

I have checked linkage, I removed PP cable from the boat when I took the stepping motor apart and put it back on, spring is good, PP is original from 2003. I'll check the set screw on the knob.

[Coach Mike]

Fuel filter?

[skiatook_bu]

Fuel filter?

It's in the linkage - the perfectpass is slipping on the other side. I can manually turn the knob, or shutting it off/on may help. the engine is running fine, just the throttle mechanically will slip and only open partially. it's been raining here but I will probably be going out today.

[skiatook_bu]

I wanted to follow up my own post for anyone else having this problem. I got the linkage worked out, verified it was working properly by watching the throttle open on take off. I was still losing power at the top end engine would rev up to 4500 and then drop to 3000 RPM. I changed the fuel filter - same problem - check the fuel pressure and it was dropping to 15 psi. It turned out to be a small screen up inside the input nipple of the fuel pump that was clogged with black particles - I pulled the screen out and cleaned it with brake cleaner and now have full throttle again.