calling all prop guru's

[brokeboater]

i have a 21' cuddy cabin with fiberglass hardtop, 1999 200 hp carbed johnson, 70 gal fuel tank 2/3 full, 2 batteries, (2) 200 lb guys on board, coolers, fishing gear and a 85 degree day. current prop is a 14.25 X 17. OEM book says operating range is between 5 and 6000 rpm. she will turn 5400 trimmed to the max at about 43 mph (gps). i'm worried not getting to the top end of the operating range can (is) cause me problems at other rpms. she will cruise at about 26-27 mph at 3800 rpm and sounds like the motor is turning free. but if i slow down to 3000-3200 sounds as if it gets in a bind. should i go to a 15? what effect other than increasing rpm would that have?

 

[Dhadley]

Re: calling all prop guru's

If the motor is mounted all the way down, I'd try moving it up a hole or two. Then test with the same prop.<br /><br />Good luck!

 

[ob]

Re: calling all prop guru's

What Dhadley said.Also ,if its in your budget,your setup is a good candidate for a jackplate.

 

[brokeboater]

Re: calling all prop guru's

mounted as high as holes in transom will let me. still have holes on bracket but bottom holes in transom can't be moved up without redrilling. believe it or not the floor is in the way. the antivent plate is about 1/4" above keel. i guess i could spring for a jackplate if raising it would be a sure cure.

 

[ob]

Re: calling all prop guru's

So you're sayning the two bottom bolts are already against the two bottom slotted holes of the transom bracket?

 

[brokeboater]

Re: calling all prop guru's

ob, that is correct. i still have 2 top holes i think. when this boat was rigged, they drilled the holes as close to the underside of the floor as possible, i guess to give as much -up- adjustment as possible. (bottom holes are accessed in bilge) problem is...it is as high as it will go. the bottom holes being the problem. the bottom holes really couldn't be redrilled higher without the floor interfearing. <br />i have examined the plate idea some. i think one of the solid setback-lift (nonadjustable) would work. this is not a "hi-performance" boat but i would like it to be right. thanks

 

[Dhadley]

Re: calling all prop guru's

One of, if not the best manual plates is the one from Bobs Machine. It has all kinds of options and is very reasonably priced. I like it because it can convert from a 6" setback to a 3.5". It has trim angle options too. Very nice, very very easy to adjust while in the water testing. If you ever decide to sell it, they are easy to sell.

 

[ob]

Re: calling all prop guru's

Just to bring to mind as a matter of consideration is the addition of some planing or trim tabs to the lower tansom.While these will not afford your engine higher WOT rpms ,they may help with repspect to the bogging issue at or around the 3000 rpm range.They may also help your engine not to struggle as much at getting the boat up on plane.Just some other food for thought.Good luck with whatever you choose.

 

[brokeboater]

Re: calling all prop guru's

thanks fellas. this link is to a pic of what i was thinking of. http://rickracers.com/product_info.php?cPath=50_120&products_id=2670 <br />it doesn't allow for adjustments but it does give lift and setback. they also sell the bob's machine one's too. i figure once i get it set it won't be moved.

 

[Dhadley]

Re: calling all prop guru's

For a few bucks more I'd still go with the Bob's. The advantages way out weigh the small price difference.