1997 GTI stumbling and no power until warmed up

[tsdub86]

1997 GTI. Replaced all grey lines 2 years ago. Pulled fuel sending unit last year to fix fuel gauge issue. Ended up not having time to fix the sending unit so I reinstalled. Ever since then, I've had issues when the motor is cold. The ski will bog down and stumble while on the throttle. It idles great, can do circles while idling no problem. Slowly, if I feather the throttle, I can get the speed up a few MPH at a time over 10-15 minutes. Eventually, the ski will run top speed after babying it for 15 minutes. It will then run great the whole time I have it out until I shut it down again. Then I have to repeat the same process. I replaced the carb (didn't want to deal with a rebuild) with a brand new mikuni. It still presents the same issue. I've bypassed the fuel selector switch and the inline fuel filter and no change. Could there be a problem with my fuel sending unit? I don't have a spare but could buy a used one.

 

[mikidymac]

Did you put the correct jets, needle and seat and pop-off spring in the new carb?

 

[tsdub86]

Its the stock oem carb for my ski. Wouldnt it come with the correct jets, needle, seat, and spring?

Also the symtoms are exactly the same with both the old carb and the new carb. With the old carb it ran perfect until messing with the fuel sending unit.

 

[mikidymac]

The carbs do not always come with the correct jets, springs or needles and seats.

If the only thing you changed from running good to bad was the sending unit then yes, that should be your first item to check.

You would not be the first or last person to mix up the hosed upon reconnection.

 

[tsdub86]

I'll recheck those. Just curious...if the hoses were mixed up, would it ever run normally? Because after about 15-20 minutes of warming up and putting around I can eventually get it to run wide open full speed on the water.