[kelster1574]

I took our 1991 Diablo MX 180 out for the first time since picking it up last week. It idles a little rough and died a couple times while idling. But when it was under throttle it ran GREAT!!!! I am thinking once I get the carb cleaned and adjusted it will good to go. It currently has a 14 1/2 - 17P aluminum prop 3 blade prop. I noticed that if you trimmed it up to quickly it would have a little blow out. I am thinking once I switch it out for a 19P 4 or 5 blade stainless prop it should not only eliminate the blow out but reduce the WOT RPM's right inside the 4400-4800 recomended range. Right now it will hit about 5200-5300 with that 17P aluminum 3 blade on it. All in all I am very happy with the way it ran.


Some more info -

Oil Pressure 60 (is this normal)
WOT RPM 5200-5300 (way to high)
Temp 140 (is this normal)
44-46mph at 4500-4600 RPM's (seems about normal)

[mikeyt]

Glad to hear your initial run went reasonably well. As i mentioned in the prop thread, if you change that prop to a 19" you will drop 4-500 rpms which will get you just inside the recommended range and near perfection. It may be a bit of old gas gumming things up so give the carb a cleaning first but dont be surprised if it needs a rebuild given the age of the boat.