Prop (or maybe tach) problem...

[saumon]

Hi everybody,<br /><br />first of all, please excuse my english (i'm french speaking). <br /><br />I recently chip the prop on my engine and i want to buy a new one to keep the old one as a spare. I want to know if i had the right prop for my 1993 Mercury 60 hp ELPTO 2-strokes. The motor is mounted on a 1993 Tracker Pro Deep-V 17. The prop that came with it is an aluminium 10 1/8 in. x 15 pitch.<br /><br />The specified rpm WOT range is supposed to be 5000-5500, but the engine run aroud 6200 rpm with this prop at 35 mph, according to the tach on the boat, and get on plane in approx. 10 seconds.<br /><br />I hesitate to change for a higher pitch prop (in order to decrease the rpm) cause i think it will be hard to "get out of the hole".<br /><br />Are this tach reliable, and can it be the problem? The engine run smoothly for 2 years now, with an average of 150 hrs/year. Is it possible that the reading of 6200 rpm could be right and, if so, im i supposed to see clear signs of over-revving, like hot water out of the telltale or something else?<br /> <br />Thanks for your input.

 

[roscoe]

Re: Prop (or maybe tach) problem...

Difficult to know if your tach is faulty unless you are able to test it, or replace it with another tach (borrowed) for testing/verification.<br /><br />In my experience, most tachs are reasonably accurate, unless they are displaying erratic readings.<br /><br />Does the tach display a reasonable reading at idle (600rpm) ?<br /><br />Do you have a spare prop?<br />If you do, what size is it and have you tried it out yet?<br />Perhaps order up a new one with a 1 or 2 inch increase in pitch, and try it. Use the best one, keep the other one as a spare.<br /><br />Please don't apoligze for your english, its better than most of ours.<br />But you had best be careful. If you keep typing in english, they will likely boot you out of Quebec. <br /><br />Another method to reduce the rpm is to make the boat heavier, by adding more fishing gear. Peace.

 

[saumon]

Re: Prop (or maybe tach) problem...

Does the tach display a reasonable reading at idle (600rpm) ?

Yes<br /><br />

Perhaps order up a new one with a 1 or 2 inch increase in pitch, and try it. Use the best one, keep the other one as a spare.

That's what i'll do. I had a very great Merc Dealer who said i'll let me try the prop and change it if i need.<br /><br />

Another method to reduce the rpm is to make the boat heavier, by adding more fishing gear.

I'll try to fill the livewell instead <br /><br />Thanks a lot!

 

[roscoe]

Re: Prop (or maybe tach) problem...

In my case, adding fishing gear is easier than filling the live well. <br /><br />Good Luck.<br /><br />Make sure you thank that Merc dealer with an additional purchase, oil perhaps.

 

[davejnz]

Re: Prop (or maybe tach) problem...

I'd definately go with an increase in pitch,maybe a 17 will put you aroung 5800RPM.You can use your power trim to help you jump up on plane faster and/or consider getting some trim/smart tabs as well.