convergent
Petty Officer 1st Class
- Joined
- May 17, 2010
- Messages
- 385
I posted this before and the thread died off because the problem went away, but now it came back. This is a '93 Mercury 115HP 2 stroke. It starts on the first turn of the crank when cold nearly all the time and overall runs very smooth throughout the whole power range of the motor. The last few weeks its developed a problem when its cold where just around 3000 rpms it will sputter and stall a bit. If I feather it a little it will do this for about 5-10 seconds and then open on up OK. When we've been doing water skiing, it might do this for the first 1 or 2 pulls but then be fine after that for the rest of the day.
The suggestion made was to spray Power Tune into it as there may be carbon deposits building up. I read the instructions for this on the Power Tune website and it says to spray the whole can into the intake while its running and then let it sit for a while. The questions I had were a) where do I spray it in? and b) how does this work when its a 2+2 engine and 3 and 4 don't kick in until over 2000 rpms? Would I need to crank it up to 2500 with fast idle while I spray this in? That doesn't seem like a good idea to me.
Also, just thinking about the carbon deposit theory, why would this ONLY be a problem when its cold and only around 3000 rpms? I would think carbon deposits would be a problem throughout the range and even when its warmed up, no? I guess it could be carbon deposits in the 2 cylinders that don't kick in until 2000 rpm, but that brings me back to the question about how to get the Power Tune into those cylinders?
Thanks for any suggestions!
The suggestion made was to spray Power Tune into it as there may be carbon deposits building up. I read the instructions for this on the Power Tune website and it says to spray the whole can into the intake while its running and then let it sit for a while. The questions I had were a) where do I spray it in? and b) how does this work when its a 2+2 engine and 3 and 4 don't kick in until over 2000 rpms? Would I need to crank it up to 2500 with fast idle while I spray this in? That doesn't seem like a good idea to me.
Also, just thinking about the carbon deposit theory, why would this ONLY be a problem when its cold and only around 3000 rpms? I would think carbon deposits would be a problem throughout the range and even when its warmed up, no? I guess it could be carbon deposits in the 2 cylinders that don't kick in until 2000 rpm, but that brings me back to the question about how to get the Power Tune into those cylinders?
Thanks for any suggestions!