Hey Guys, I have a 2000 225HP Optimax Ser # 0G839677 that is running like crap under way / load. It starts, idles and revs perfect but in the water it starts breaking up / surging at around 1200, wont really accelerate unless I floor it then the engine will surge a few times and then accel hard to near 3K, when it hits 3k its not sounding like its on a rev limiter but more like the engine is maxed out, I have the throttle all the way open but thats all it has, it will run 3K for a second than drop to 2500, then slowly bog it self down over a several minutes running worse and worse even with leaving the throttle at WOT. I used to work on cars for a living, if this was a car I would suspect the timing or fueling curves are off but I not familiar enough with optis yet to know how what affects what
So far I have done...
Replaced all filters
Opened the VST - looked clean, no debris or fuel hose bits
Checked pressures - I got 92 fuel, 82 air, 6-ish low pressure
I checked spark with a gap tester and it jumps 3/8 in no problem on all 6
I pulled the injector connectors one by one and each made the engine run rougher so all 6 are firing
Pulled the low pressure pump connector and low pressure PSI dropped from 6PSI to 0
Rebuilt the pulse pump on the side of the block
Pulled the high pressure pump connector and it instantly stopped running
Compression cold is 90ish on all 6, my understanding is doing the special optimax method will yield 20% higher
Plugs not fouled but noted each one had a little bit of wet oil on them, probably from incomplete burn. Replaced end of last year, minimal hours on them.
Tracker and diaphragm both replaced last year
Ran on a 3 Gal tank with a half bottle of quickleen
I have no beeps at this time, I know I need to get the codes scanned... I still need to find a decent shop that knows optimax, what should I ask for from them? I talked to one shop and he said all they know how to do is read hard faults, if something has a hard fault it will beep right?
At this time I am trying to self diag and I like having spare parts for common failure items, I had a spare inside TPS, it made no difference, was thinking about ordering an outside TPS, the thing that goes in-between and a crank sensor aka "enoder" to try next. I have seen failing crank sensors on cars kill the mid range and the reason for TPS is I find it odd that it will sputter and surge if I WOT and then jump to 3K like its all good before it starts bogging down again.
Any ideas of what else to check / replace?
Here is a video of it surging with gauges, the air is kinda hard to see but its holding 80, the low pressure is bouncing from 5 to 8, I am suspecting its from the float opening and closing but it could be the gauge is too big to accurately read it. If I hold WOT and let it stutter to 3K the pressures all stay the same... https://streamable.com/3zjz5x