Basic prop question: plastic inserts?

[Okie2]

Have a Mirage Plus that has the 3 black plastic circular inserts at the base of the prop. Purpose of the tabs? Just curious.... Thanks, Scott

[MOP]

With through hub exhaust some of the exhaust escapes out of the hole to let the prop spin up a little faster, that gets most boats out of the hole a little quicker. In the early 80's OMC sent out tech bulletins to drill 5/15" hole to help some of the azz heavy boats to get on plane quicker. The first boat we fooled with was a 25 Grady with T/200 Johnsons, we ran it out a few times to get a pretty solid time from dead to plane. The mod made a four second difference the owner was estatic said he sould not believe it, he was thr type that hauled twicw as much as needed gear and beer wise along with 3-4 buds. On a light boat say a 16 or 18 you may not see much, but it made a noticeable difference on my 22 which is a SB so a little extra on the bottom is nice.

Phil

[BigGrizzly]

Actually use the full plug.

[widowmaker]

I second Grizzly's comment about using the full plug. I have experimented with temporarily "plugging" the vent holes on various props that I have tested on my 22.. In almost every case, the vent holes contributed to the prop "blowing out" when coming on plane. With the holes plugged with short carriage bolts, the change getting on plane was dramatic. My exhaust exits through the transom only.

[mike o]

Hi, I have a laser II 25 pitch on my 4.3 lx, 95, 16. There are no plugs in the vents. It dosent blowout, but would I benefit by installing the plugs?

[widowmaker]

Hi, I have a laser II 25 pitch on my 4.3 lx, 95, 16. There are no plugs in the vents. It dosent blowout, but would I benefit by installing the plugs?


The only Donzi experience is with my 22, and I do not have any experience with your prop. In my testing, while plugging up the vent holes helped me tremendously getting up on plane, it did not help (nor hurt) my mid-range performance or my top end.

[Donziweasel]

Got her out again yet?

[mrfixxall]

mercury sells a plug kit with solid plugs to various size holes in them for fine tuneing your holeshot..