Checkmates - To Cone or Not to Cone??

[cm21]

Looking for some input on nosecones.

I have a 1986 21' Checkmate;200 Merc with milled heads (previous owner says that it puts out 235 HP??); Bob's Nosecone; Bob's Manual Jackplate; 24 Chopper.

I have read some posts suggesting that nosecones can do more harm than good on heavier hulls like Checkmates.

I am currently running 66-68 MPH @ 6700 RPM and looking for some more speed (of course).

It seems unanymous so far that I need more setback for this hull, but should I lose the nosecone??

Any comments/opinions on this.

Is there something that the noseconed gearcase is doing other than allowing me raise the motor?

[check88]

well the reason that the cone is helpful is to be able to lift the motor higher on the jack without running out of cooling water.i run the tip of my cone about a quarter of an inch below the pad on my starflite and with out a low water pickup cone this would be impossible.i think i read somewhere that on heavier hulls like the checkmates that a cone does help on the full size gearcases at speeds of 70 and above.how much setback are you currentley running and how high up do you have your motor jacked ?i have found that by goig to at least 12" of set back that the bow can start to fly itself much easier and with less positive trim than without setback.just check the transom integrity before you go back that far.

[cm21]

check88- I have the motor at about the same height as yours, but I need a lot of positive trim (throwing a huge tail) to get top speed of 67.

Only have 7" of setback now (5" from Bob's jack plate, 2" spacer).

Looking in to the 11" Extension plate from Hydro Dynamics to replace the 2" aluminum spacer from Bob's.

[DaveR]

For cost reasons, you may want to check out bying the two angle plates from Bobs that will turn your 5" setback to 8". They will sell them separately ( I did it) so you don't have to buy the hole thing. use the 2" blocks and you go from 7" total to 10" total pretty cheap. Just a thought. Of course if you really need more than 10", don't waste the $.

Yes, you really need about 14" of setback, possibly 16" with a 200. Make sure you dont have any dead weight up front, take it out or move it back as far as possible. A nosecone is supposed to only help above 80 mph, but it's also the only way to get the water pressure needed for high transom heights. I wouldn't add one to mine unless I was getting over 80 mph, as the normal bullet works better below that speed with heavy hulls and lower engine heights. Can you borrow a normal lower unit? That would be a great test. Local dealer recommends the Tempest prop for good all around use and top speed, but says if you can find a good used Mach prop, that was the best for them.

[LaveyT]

Kind of a Hill Billy idea(been hangin with Instagator) but it worked for me.I ran my old YT bowrider with a 175 with the top water intake siliconed closed on each side for 13 years.Im currently running the Lavey that way also.Now if I could just get the gonads to silicone the top two on each side and raise the motor....But Im not sure it would be enough flow.A boat mounted low water pickup is a possibillity also.Good luck

[WillyT]

I would leave the cone on and concentrate on the extra setback. Bob's is one of the fastest, if not the fastest cones, and once you get the setback you need, you will be in the range where you will be glad you have the cone. It is good insurance against overheating in any case. If you go with the maximum setback, you may find that you need transom wedges (and/or some type of whale tail) to help the bow stay down on hole shot, or to stop porpoising at cruise speeds (I have both on my Sleekcraft, and they work great), but your "bow heavy" boat may not require this. Your boat can easily use 12"-16" of setback. I suspect that the closer you get to about 16", the faster you will go.