1987 175HP no mid-range

[champion18]

I have a 1987 175HP 0n a bass boat. My problem is it has no mid-range. I have rebuilt the carbs, rebuilt the oil pump, rebuilt the fuel pump, ran Seafoam in the gas, checked the stator, dis-connected the idle stabilizer, checked compression and all cylinders were 90 psi and all even. The motor will start and run fine up to about 1200 rpm's, but if I try to go past that the motor dies. If I slam it to wot it will take off and after it planes out it will go 65 mph all day. I don't know if it is carburation or ignition. Any suggestions will be appreciated.

[boats.net]

Try removing and cleaning carbs and recheck sync.

[champion18]

I have wh-34 carbs and have been cleaned and had pipe cleaners and tip cleaners run through every orifice and new gaskets. I have done the link and sync several times according to the manual. I have checked and rechecked the timing. I am stumped.

[boats.net]

Check to see if timer base moves freely or is hanging up, check reed valves, with a timing light check for cylinder misfire.

[champion18]

I took the boat to the lake yesterday and this is what I found. The motor will idle just fine, but when I put it in gear the engine dies, unless I jam it to mid throttle, then it chugs along at 1200 rpm’s. If I try to go above 1200 rpm’s it will die, unless I jam it to wot then it hesitates until it builds rpm’s and then it will take off and plane with no miss. I can take it down to 3000 rpm’s and it runs fine but not below that. I am thinking either stator or switch boxes. Any thoughts?

[boats.net]

Possible, try the timing light to see if loosing fire.