Sluggish HX

[Blue pearl]

Hey all,
I have a 96 HX that I cannot seem to get running right. Fuel lines have been replaced, carbs rebuilt with oem mikuni and new gaskets. I dont have my spec sheet handy iirc pop off in both carbs was ~49psi. Needle and seats held 20+ psi over time. The fuel pump seems to flow fuel well into the carbs, although there are air bubbles time to time. Stock jetting sizes. Replaced rotary valve + cover and set timing. Trimmed back plug wires. New Spark plugs. Compression 135/140. Always 93 octane fresh fuel. Fuel system also holds 3ish psi. To my knowledge, there are no aftermarket parts on the ski
Performance of the ski:
Excessive cranking to start in or out of the water. It idles well and seems to have decent response from idle to half throttle. If I cruise at half throttle and then open full, the power comes on very slowly. Once at full RPM, it seems ok. It also struggles to drag me through the water and has a hard time taking off. Every other HX I have ridden seems to want to jump out of the water, including my wife’s 95’.
Could this be a jetting issue? Even tho I am running factory sizes? Could a bad coil cause this performance? My friend also mentioned to me to check if the crankcase is holding pressure. If that is a possibility, any suggestions on how to test that?
Overall, the ski just feels “weak”

Help will be much appreciated.

 

[mikidymac]

Compression is a little low but still within spec.
Try pulling the choke a little when going from half to full throttle and see if it will get better as it could be lean and this will help diagnose that as it will richen it up.

It does sound like you have covered the bases so I would also try unplugging the red wire on the voltage regulator and see if that does anything although they typically cause issues on the 787.

Finally did you say you have a 95' HX also? Might be time to try swapping parts to find out what is bad.

 

[Blue pearl]

Compression is a little low but still within spec.
Try pulling the choke a little when going from half to full throttle and see if it will get better as it could be lean and this will help diagnose that as it will richen it up.

It does sound like you have covered the bases so I would also try unplugging the red wire on the voltage regulator and see if that does anything although they typically cause issues on the 787.

Finally did you say you have a 95' HX also? Might be time to try swapping parts to find out what is bad.

I think I did try playing with the choke a few weeks ago out there, but actually forget the result. Next time out I’ll play with that again.
what does unplugging the red wire from the voltage regulator do? Could this be an ignition timing thing? As far as I know the timing on these is not really adjustable other than a small ammt by moving the stator coil.
as far as swapping parts, I’d like to save that as a last last resort.. i just got that ski going after a sheared flywheel key fiasco.

 

[mikidymac]

The stator actually puts out AC voltage and the regulator converts it to DC voltage that the CDI and electronics need to function. When the regulators go bad they allow alternating current into eh system and cause all kinds of weird things to happen. When you unplug the red wire ti disables the regulator from the system so your ski is only running on the battery for clean 12V DC current but it will only run until the battery is dead. If it runs fine with the red wire unplugged you know the regulator is bad.