View Full Version : 98 XP limited power problems

08-30-07, 11:38 AM
My 98 XP is having problems with power. I have had the prop changed, due to 5K feet altitude. Running very rich, shop turned down the carbs and now I am only getting 6,000 rpm, before used to get 6900. My Rave valves are loading up with oil and carbon too. Has anyone seen this, I am thinking that they have taken my carbs down too low, and I have them jetted also. Does anyone know if there are adjustment screws on the bottom of the carbs for the top end?

08-30-07, 12:07 PM
yeah sounds like it. THere are high speed screws right next to the spring for the throttle. It should be sealed by a plastic cap, but you don't remove the cap to adjust it. There are pictures and details instructions for how to adjust them in the shop manaul, but basically counterclockwise will richen the mixture and clockwise will lean it out.

09-11-07, 05:04 PM
I agree with Joe, sounds like your running to rich. Especially if your noticing oil and carbon build up on your rave valves. There should be some light carbon build up over years of use, but no real oily residual. With the presence of oil, running rich, the motor's not getting hot enough to burn off the lubricating part of your oil. Careful on leaning it out though, to much can lead to serious damage.........and check your spark plugs, this will tell you if you need to lean out or enrichen.
Looking at our manuals for your engine, there is a paragraph I read in there about re-jetting the carbs for altitude and temperature. There's several pages on how to adjust your carbs from a dead start. Way to much detail for me to try and give you here, but detail that's easily understood by someone who has basic mechanic skills. A very important section on adjusting the oil injection pump if your carb adjustment changes these settings (provided your not using pre-mix instead).