Low RPM's, bogging? 97 GSX

[BigAl57]

Hi, I am new to the forum. I have a 97 GSX I bought used (and apparently abused). I had the top end rebuilt and the machine ran great last year. There is some kind of pinging noise that seems to be in the lower unit, but more concerning is the problem I am having this year. I had it running, and revving, great on the trailer and actually had it out on the water for about 5 minutes running full out without problem. Then the revs dropped and I had to limp back to shore. Even at full throttle the RPM's were 1260 or so. If I took my thumb off the throttle the ski actually stalled out. Out of the water it revs hi but back in and the same problem. When I opened the seat there was also a lot of smoke pouring out. No sign of overheating but I wonder if the problem could be fuel related. I noticed it still has the grey fuel lines. Would the lack of fuel cause the symptoms I have described? Not sure about the smoke. The previous owner removed the oil supply so I have to use premixed gas/oil. I was told to go 40:1. Any ideas? I am hoping to get it running in time for my vacation in 3 weeks. Thank you

 

[Coastiejoe]

Do a compression test. If the numbers are good, the replace the Grey Tempo lines, fuel selector and do a MAJOR cleaning of the carbs and plastic filters within the carbs.

 

[BigAl57]

Do a compression test. If the numbers are good, the replace the Grey Tempo lines, fuel selector and do a MAJOR cleaning of the carbs and plastic filters within the carbs.

thanks, going to the cottage this weekend. I'll check the compression and go from there. Just curious, what numbers should I be looking for? I have read that they need to be within 10% of each other but not sure what the values should be.
Thanks,

 

[Coastiejoe]

thanks, going to the cottage this weekend. I'll check the compression and go from there. Just curious, what numbers should I be looking for? I have read that they need to be within 10% of each other but not sure what the values should be.
Thanks,

150 psi is like new, 130 is normal ok range for good running engine, 120 it normally runs but is near the point of needing engine work.

 

[Seadoobuddy]

You stated that a lot of smoke came poring out when you removed the seat.
If you have an exhaust leak inside the hull the smoke will smother the motor and made it run really bad...(ask me how I know)


But cleaning the carbs and changing out the fuel lines is the first step that needs to be done. I would also add an in-line fuel filter. A Fram G-2 works great.

 

[Coastiejoe]

Excellent point,,, Engines do need their oxygen...

 

[BigAl57]

thanks, I'll take a look at the exhaust if I get the bogging sorted out.