looking to get better performance from my hightide. its got a 19p aluminum prop on it now. only get about 43 top end and was expecting mid to upper 50’s. any ideas on what pitch? dont have a tach so not much info to go from. its a 90hp merc 2-stroke.
Messing around with props without a tachometer could be a volatile situation for your outboard. JMHO
Northern tool sells a tach that attaches to one of the spark plug leads and is powered by a self contained battery: http://www.northerntool.com/webapp/wcs/stores/servlet/NTESearch?storeId=6970&N=0&Ntk=All&Ntt=tachometer&Nty=1&D=tachometer&Ntx=mode+matchallpartial&Dx=mode+matchallpartial . I would try a Merc stainless of the same dimensions and work from there.
www.propgods.com get some info then post to the forum. ken can answer just about nything about props and will swap em til ur satisfied. need to know top speed prop pitch and wot rpms.
quote:
looking to get better performance from my hightide. its got a 19p aluminum prop on it now. only get about 43 top end and was expecting mid to upper 50's. any ideas on what pitch? dont have a tach so not much info to go from. its a 90hp merc 2-stroke.
Something must be wrong with your motor. I have the same boat with a 90hp Yamaha 2-stroke and have hit 51mph by myself and light on fuel. With 2 people and full fuel it will do 47-49 easily. My prop is a powertech 13.25" x 19".
I suggest that you buy a tach, so you can see what you’re turning. That 90 Merc should have that boat flying.
Nothing but a “SMART-ELLIC”!
i do need a tach, thats a given. motor had to be repaired when i bought it in feb. (new flywheel, foot seals, impeller, fuel pump, carbs, etc, etc.) but mechanic gave a clean bill of health when we were done. he pluged in a tach while river testing and said that i may need more pitch, just didnt say how much. thinking maybe motor is hung too low on the transom as well. likka, what hole is your yamaha on?
hightide 1602sc
90hp merc
alumnicraft 14’
25hp merc
I have done business w/ Skips Prop Shop on Cross-couonty Rd for years. He has even loaned me his plug-up tach to test run mine and report back so he could tweek my props. If your motor is too low on the transom, that is a whole different issue. Proper engine height is first priority, then RPM’s verification, then prop changes, if any. I am a big fan of custom stainless props over aluminum 100%, so do consider that potential change once you have other issues squared away. Hhope that helps some.
If the motor is to low on the transom, you need to be more concerned with a “Jack Plate”. Then start worrying about the prop. Your motor will “never” work for you if it’s buried to deep in the water!!A good rule of thumb is, the bottom of the mid section where the large fin is, should be no more than 1.5 inches below the bottom of the boat, and that may be too much. Actually the fin should be flush with the bottom for maximum results. Again JMHO Seeya, Scott
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likka, what hole is your yamaha on?
Mine is mounted in the very bottom hole…In other words it’s mounted as high as it can go.
Nothing but a “SMART-ELLIC”!
That is why I am buying a jack plate for my rig. The cavitation plate should be above the plane of the hull easily over 1" typically. Mine needs an even higher setting.