Why am i so disappointed in merc 1500

[Bob_VT]

Re: Why am i so disappointed in merc 1500

Be VERY careful when/if you raise the motor height.

I did that with an inline I built and when it got too high it had two significant results. I could not make left turns due to prop torque and I blew up the impeller. I was lucky I was running a water pressure gauge. Many people that run the inlines real high get low water pick-ups so the engine will not blow up.

Yes, waxing a hull is not as fast as one would think. The easy answer to explain this is a golf ball...... the dimples create disturbances and help it fly through the air. A waxed hull does not create the disturbances and the hull rides on water....... small disturbances would allow the hull to ride higher and faster. I once sanded a hull and picked up 3 mph.

 

[monk-monk]

Re: Why am i so disappointed in merc 1500

Thanks for that info, Bob! I understand what you are saying..point well taken! An trust me, im not the kind who immediately "jumps" on something i hear..i study that info, look for the "other side of the story" before i react...im still taking all this in...

 

[wired247]

Re: Why am i so disappointed in merc 1500

You have to go quite high to get the water pickup holes out of the water . up to 4 inches prop centerline under the bow you won't have any problem. You can go much higher than that with a lWPU or even the bolt on Mercury side scoops. As far as props blowing out turning that has nothing to do with the height of the motor. It does indirectly but it has more to do with propping the motor correctly. You have to expect that if you are going to radically change motor height that you are going to need to invest in a different prop unless yours is good to go already. Some props ( All aluminum ) cannot be surfaced even with the trim adjustment or they will cavitate themselves to death.

 

[monk-monk]

Re: Why am i so disappointed in merc 1500

OK, great discussion here friends!! Thanks! With this info, i have developed a game plan...im not going to get radical with my approach, but from what i experienced last time out with boat, i do believe i need to raise the motor up..i proved that to myself because i knew that as i trimmed motor up it was running faster (obviously ventilation plate was not even level, but boat was running faster) im going to "sneak up" on this re-positioning of motor. FIRST question: Wired247, in your last post you said i need to have a prop of the right material as aluminum would cavitate itself to death..what should my prop be made of (stainless?)

 

[monk-monk]

Re: Why am i so disappointed in merc 1500

SECONDLY, what is a good starting point for setback if i have the motor about 5" below bottom of boat...im going to sneak up on this situation, but i know i need to get this motor raised...i have no clue as to my current prop size as there is no markings on it to tell what it is, but i will find and post info on hull wegh so i can get an idea of prop size i should be running

 

[wired247]

Re: Why am i so disappointed in merc 1500

The higher you can get the motor the less trim you will need. Trimming the motor up causes drag even though it helps a bit for speed.

A good quality 17-19 pitch 3 blade stainless prop will work well for your inline. When I say an aluminum prop will cavitate itself to death I mean it. Ive got a month old solas aluminum prop that blew a bade apart in my garage from running too close to the surface.

 

[monk-monk]

Re: Why am i so disappointed in merc 1500

oh yeah, i know that trimming the motor up or down puts the ventilation plate "out of plane"...raise motor and you're dragging stern of boat down, lowering motor lifts stern...ventilation plate should stay parellel with degree of plane of hull...and i understand that bow should be slightly up...Quick question: as for amount of setback, would it be fair to say that, the higher you raise motor, the more setback required?...trying to figure out how much setback i need...jack plate lift is adjustable, setback is not. don't want to waste money on wrong setback...i plan on raising motor about 4/5" tops...suggested setback for that?

 

[wired247]

Re: Why am i so disappointed in merc 1500

I wouldnt waste money on additional setback devices unless you are putting some serious power to a surfacing prop. You are running a inline on a runabout. Don't get all happy with yourself. If you put a jackplate on there it will have more than enough automatic setback. A 6 inch jackplate will set it back 6 inches or so anyway.

 

[Faztbullet]

Re: Why am i so disappointed in merc 1500

If your hull is a "V" bottom or anything that isnt a "pad" save your $$ as set back and surfacing props will help little or if any. The small blade chopper Merc came out with years ago was basically for inline motors..

 

[monk-monk]

Re: Why am i so disappointed in merc 1500

OH im not "all happy with myself" Wired...as i stated, im not going to engage in drastic measures here! I am happy with everyone that has helped me, very much appreciated!! I appreciate everyone working together to help me in this matter! I love my old Mercury motors...again, my motors purr like kittens, i just wasn't realizing all the hype i've heard about these motors...I have learned very much from this discussion, thanks to y'all...when people tell me something, i don't just hear noise, i listen to what they are saying and the point they are trying to make...because of everyones help, i now have a direction and im sure i will have positive results. THANKS!

 

[wired247]

Re: Why am i so disappointed in merc 1500

Pick up a small eared chopper off ebay . You can usually get one for a couple of hundred bucks. A real Merc one not a copy. They are very steering neutral and easy to drive. Not great out of the hole but they do pretty good on the top end. You'll want a 22-24 or so pitch. They slip like crazy so dont let that number scare you. The pitch makes up for the slip.