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  1. #1

    Speed increase with Head gasket mod and intake screen removal?

    Just finished reworking my 1999 Xl1200ltd with changing the head gasket to 1 layer (coated) and removal of the backfire screen from stock intake box (silencer removed). Ski has richer jetting 95p,120m, polished ports, D, ride plate, intake grate, sponsons, oil in gas, premium gas, and would hit 60 mph per gps (68 on yamaha guess meter). Curious to see if any speed increase, will let you know. Yes, I know my sign says 65 but that was before checking gps.

    P.S. Guestion, if the catalyst is gone, is the rear pipe light enough to remove the bottom support plate that prevents you from seeing rear carbs and lines? Has anyone else removed and had any problems? Removing that plate would lighten as well and it sure would help with maintenance and removal.

  2. #2
    improvised tmg97gp's Avatar
    Join Date
    Jul 2008
    Chesterfield Virginia USA ~ On the James River~


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ID:	250296Leave the support there, drill a one and a half inch hole in the middle of it. Then you can see your hoses and the high speed mixture screw on your second carb.

  3. #3
    Thanks, that is good info, I definitely will cut the hole next time.

    Another question, I was disappointed with my head gasket and intake screen delete, more power but no more speed. The power can be felt on accel and cornering but the rpms and top speed was identical. How are you getting the higher rpms for increased speed, it is hard to know if I need to be looking at the motor or the hull (ride plate, grate, pump nozzle, impeller) to get me a couple of extra MPH?? The motor seems to run very strong as is. Can the Riva ride plate be improved on significantly? Does the Riva intake grate help or hurt top speed?

  4. #4
    shiftarno's Avatar
    Join Date
    Jul 2010
    good info

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