WhiteZombie
Member
When I throttle up, at around 3/8 of full throttle position on the handles, I'm getting hesitation on both engines. from 2500 to 3000rpm range Most every time I've took it out I've had either of the two engines die right at that spot. I am consistently seeing this rpm range. Usually when I get the killed engine started it usually will take on off and both engines stay running. With that said, on rare occasions it can take several tries. One trip I think I attempted to take off 4 times before they would stay on long enough to get above 3000. Also, I will mention that it does it whether I have been driving slow out of a long cove I go thru or out on the main body of the lake.
As far as fuel, I use 87 octane per the manual. I rebuilt the carbs back in the spring and other than this one issue it runs great. I have to choke it a bit at cold startup now that it is cooler, but back in the summer it cranked pretty much first try every time. It is just something about this rpm range. I thought I had read before that this is a problem range as is shown in the chart in the manual where the jets curve crosses. It to my understanding is a lean zone, and there is supposed to be a way to tune it out, but I cannot find that article, and though I thought I had seen reference to this phenomenon in the manual, I can not find it in the carbeurator section. I don't know, my mind is getting old but I swear I have heard reference to this. But with that said, I read a couple post just now saying that low setting is for fine tuning how the motor runs at a properly set idle which is set with the idle adjustment. And the high is for the obvious. So I take it that the pilot feeds the 2800 rpm range, and being there isn't an adjustment I can only see changing the orfice size, and I know not to do that. My High and Low screws are set to manual specs. Everything carb wise was very meticulous with even using the JIS screwdriver.
So, what can be the issue and what can I do about it? I was somewhat ok with this most of the summer and didn't adjust anything because it was running good enough. But I would like to get this straightened out before next season. I have a small water reservoir up the road I can test it out at as I try things.
Oh, fuel filters are good as I cleaned them when I rebuilt carbs etc. And yes it was the right carb kit, pop off was set, new needle valves and 10 psi pressure test, and I cleaned it as good as you can without an ultrasonic cleaner.
Like I say, it runs good other than this one rpm range. Any help is much appreciated.
As far as fuel, I use 87 octane per the manual. I rebuilt the carbs back in the spring and other than this one issue it runs great. I have to choke it a bit at cold startup now that it is cooler, but back in the summer it cranked pretty much first try every time. It is just something about this rpm range. I thought I had read before that this is a problem range as is shown in the chart in the manual where the jets curve crosses. It to my understanding is a lean zone, and there is supposed to be a way to tune it out, but I cannot find that article, and though I thought I had seen reference to this phenomenon in the manual, I can not find it in the carbeurator section. I don't know, my mind is getting old but I swear I have heard reference to this. But with that said, I read a couple post just now saying that low setting is for fine tuning how the motor runs at a properly set idle which is set with the idle adjustment. And the high is for the obvious. So I take it that the pilot feeds the 2800 rpm range, and being there isn't an adjustment I can only see changing the orfice size, and I know not to do that. My High and Low screws are set to manual specs. Everything carb wise was very meticulous with even using the JIS screwdriver.
So, what can be the issue and what can I do about it? I was somewhat ok with this most of the summer and didn't adjust anything because it was running good enough. But I would like to get this straightened out before next season. I have a small water reservoir up the road I can test it out at as I try things.
Oh, fuel filters are good as I cleaned them when I rebuilt carbs etc. And yes it was the right carb kit, pop off was set, new needle valves and 10 psi pressure test, and I cleaned it as good as you can without an ultrasonic cleaner.
Like I say, it runs good other than this one rpm range. Any help is much appreciated.
