97 XP charging voltage at idle? rectifier?

[Del Slo]

been having some issues with my 97 XP 787. it backfires under anyload over 15% throttle. i replaced all the fuel lines and cleaned out carb filters, (one was ok and the other was half plugged) it ran great for 5 mins and then right back to where it was before backfiring through the intake like crazy. pulled carbs out again, filters were ok. ive read about the voltage rectifier going bad, my charging voltage with the ski idling is only 12.4V. i could have swore it was at 13.1 last year when i first bought the boats, what should it be charging at idle and does this sound like a possible rectifier problem, what are typical running conditions of a bad rectifier??

 

[condo180]

i have the same problem with my 96 xp! try disconnecting the red wire from the rectifier and let us know what happens.. also i'm going to clean the rave valves.. i'll let you know if it helps at all

 

[Del Slo]

yea, i dunno, the battery does not seem to be draining, but the charging voltage is not there. my boat was backfiring under load, i took the carbs out and cleaned them, replaced the fuel lines, took it out, and it ran awesome for 5 mins then started backfiring and going nowhere again. took the carbs back apart and checked filters, they are ok. put new ones in cause i had them. now it starts and idles fine on driveway. as soon as you put it in the water it boggs and will not gain rpm hardly. plugs are wet. the black wire on my coil was loose, so i tightened the connection, still no change. the two wire connector on my started solenoid has a rusty pin on the solenoid side, but it doesnt change the running of the boat if you disconnect it while its running, im stumped!!! ill pull the rave valves tommorow i suppose and get back to you

 

[lilngineer]

Speaking from experience, it may be worth pulling the Magneto cover to inspect. I just had the same symptoms because the screws on my magneto rotor cup backed out and threw my timing off and tore up my stator.

Check your timing with a light and see if it's moving around on you.