I searched this forum before starting this topic, but it seems each problem in unique in its self so here is mine.
Waverunner with twin carbs, still with oil injection. Ski is about 4 years old and has 55 hours on it. Once started the ski runs fine at idle and low throttle speeds. When you get the throttle to 1/4 - 1/2 squeeze it boggs like it has something in the pump or starved for fuel. On the trailer the motor runs perfect WOT but once the pump is loaded in the water you can not get past 1/4 - 1/2 throttle without it bogging. Sometimes it kills. Every once in a while I will get to WOT but the motor doesn't increase in speed it just gets louder. I can get past 1/2 throttle and hit my primer once or twice and the ski takes off but then within a few seconds it is back to bogging down. So I thought it may be a fuel problem. I dried the tank and refilled with high octane. Even after running it down a 1/4 tank there was no change so I thought maybe carb is off a little. I made adjustments on both the high and low speed screws (even though low speed has been fine). Never made a difference. I put the screws back to factory settings and rode the ski back to the launch. Only time I got any speed was to hit the primer with the throttle squeezed. This ski is not used much and the owner lets it sit up over the off season with the fuel in it (without stabil). My thought now is the carb needs to be rebuilt/cleaned. But I had another thought, could it be the carb fuel pump is not performing? Since the ski runs fine with fuel delivered through the primer that maybe the fuel is not getting pressured to the carb. I guess either way it means pulling the carbs. I wouldn't think it would be a vacuum or other fuel hose leak, but could it. Should I vacuum/pressure test the lines and tank before pulling the carbs? I did notice that when I open the fuel cap the tank is not under pressure just after a run, but when trailered and I fill up, it is pressured then. I guess there are just too many possibilities for the cause. I didn't want to pull the carbs and find that it wasn't the problem. But then again, leaving fuel sitting in the motor for 10 months leads me to think thats got to be the culprit. Any advice would be appreciated.
Waverunner with twin carbs, still with oil injection. Ski is about 4 years old and has 55 hours on it. Once started the ski runs fine at idle and low throttle speeds. When you get the throttle to 1/4 - 1/2 squeeze it boggs like it has something in the pump or starved for fuel. On the trailer the motor runs perfect WOT but once the pump is loaded in the water you can not get past 1/4 - 1/2 throttle without it bogging. Sometimes it kills. Every once in a while I will get to WOT but the motor doesn't increase in speed it just gets louder. I can get past 1/2 throttle and hit my primer once or twice and the ski takes off but then within a few seconds it is back to bogging down. So I thought it may be a fuel problem. I dried the tank and refilled with high octane. Even after running it down a 1/4 tank there was no change so I thought maybe carb is off a little. I made adjustments on both the high and low speed screws (even though low speed has been fine). Never made a difference. I put the screws back to factory settings and rode the ski back to the launch. Only time I got any speed was to hit the primer with the throttle squeezed. This ski is not used much and the owner lets it sit up over the off season with the fuel in it (without stabil). My thought now is the carb needs to be rebuilt/cleaned. But I had another thought, could it be the carb fuel pump is not performing? Since the ski runs fine with fuel delivered through the primer that maybe the fuel is not getting pressured to the carb. I guess either way it means pulling the carbs. I wouldn't think it would be a vacuum or other fuel hose leak, but could it. Should I vacuum/pressure test the lines and tank before pulling the carbs? I did notice that when I open the fuel cap the tank is not under pressure just after a run, but when trailered and I fill up, it is pressured then. I guess there are just too many possibilities for the cause. I didn't want to pull the carbs and find that it wasn't the problem. But then again, leaving fuel sitting in the motor for 10 months leads me to think thats got to be the culprit. Any advice would be appreciated.
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