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  1. #1

    Lost 5mph top speed only going to 7900-8000rpm?

    have 8350 program use to go to 8200rpm feels like surging at WOT? Think it's PLUGS? Any other suggestions?

  2. #2
    wotxxxsd's Avatar
    Join Date
    May 2012
    Plugs and run a double dose of fuel injection cleaner.

  3. #3
    will do anyone know off hand what the plugs they are? rather get at auto parts store that dealer!

  4. #4
    Mod less, ride more! troyheb's Avatar
    Join Date
    Jul 2007
    Nederland, Texas
    Need more info.
    What charger and how many hrs on it?
    Could be some bad gas.
    Could be plugs.
    Plugs are NGK's. Pull one and take it to Orielly, thats were I get mine.

  5. #5
    HardmanGT's Avatar
    Join Date
    Aug 2009
    Rutherfordton, NC
    NGK stock number 4339. Make you you unscrew the top cap off the new plug. The coil won't fit over it if you don't

  6. #6
    changed plugs that wasn't it still the same lost about 300rpms and just doesn't have the pull it had or top end. Think Seafoam best cleaner to run thru it?

  7. #7
    TDR's Avatar
    Join Date
    Nov 2009
    Melbourne, Australia
    Check your 4 pump bolts. I lost 5 mph because i had lost 3 bolts

  8. #8
    not the water intake bolts but actually around the pump?

  9. #9
    Raul Fosca's Avatar
    Join Date
    May 2011
    Lima, Peru.
    I started loosing RPMs and after a while started with small misfires. Then started messing up spark plugs. Finally realised microcrack in my intercooler with let some seawater into the engines admision. Did intercooler pressure test with water, detergent and air presure.

  10. #10
    carried to dealer said he didn't see any problems, did two updates to computer said he hopes it fixes problem but I have my doubts guess I find out this weekend

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