115 hp 1976 merc, needs reviving

[boaterntexas]

My 1976 115 hp merc on a 17' fiberglass bass boat whieghing in around 1000 lbs is really disappointing me, when I bought the boat I was at awe by the fact that I had a 115 hp 6 cyl motor on it. It runs really good with just me on it ( 130lbs) but once ouy put another person on it, it really starts laboring, try to tube, and it really works hard to get out of the hole, once out of the hole it runs pretty good. add another person and the rpms @ WOT will drop to or below 4000 rpms. I figure that total whieght at this point would be around 130 ( me )+ 150 ( friend ) + 230 ( big ole friend) + 100 ( est. of fuel gear and batts) + 1000 (boat and motor) I figure this to be 16000 lbs. is this way to much?<br /><br /> when under lighter load such as me and one other person it still labors, anythign I can do to improve that. tips or tricks??<br /><br /> thanks for all your help<br /><br />history -- had all carbs cleaned, link and sych, prop rehubbed, new water pump, spark and compression test, all check out as good. I still have a problem when alone in the boat of reachign really high end rpm of 6000 or more.<br /><br /> thanks,<br /> THomas

 

[12Footer]

Re: 115 hp 1976 merc, needs reviving

I'm not prop smart, but you might want to borrow or rent a prop with a lower pitch from a prop shop. You msy be over-propped, or if the boat is riding low in the water, you may have soggy foam, or a plugged stringer drain, retaining water in the bow.

 

[boaterntexas]

Re: 115 hp 1976 merc, needs reviving

Now that you mention it, I bet I am retaining water I reflorred and restringered the boat, I had now cluewhat I was doing, and when I glassed it in I didn't make way for water lower than 1"in depth to get form bow to stern, but I can't imagine that being much whieght. I didn't refoam, so thatsnot the prob, the prop pitch is a 21 p prop, I've heard it needs work, but I've also been told it was fine, I guess your right on track with renting or buying a new prop. I really don't have any means to rent as I have never heard of that around here, and I definitly don't have the cash for a new one.. anyone want to send me their spare prop, sounds like a risk, but I a very trust worthy christian guy. yeah right no-ones that kind. thanks for your help<br /><br /> Thomas

 

[boaterntexas]

Re: 115 hp 1976 merc, needs reviving

well rule out prop slippage, warter log, even with just em on there it doesn't seem to do what a 115 should do... any suggetions?

 

[sharkcat]

Re: 115 hp 1976 merc, needs reviving

It sounds to me like you are overpropped/or your prop is damaged.Even small dings/bends can make a huge difference.This guy may be able to help emailropdok@aol.com.<br />You should check out the hustler prop range.Also remember that your engines HP rating is probably at the flywheel.Later engines are measured at the prop.So you may have only 90HP at the prop.Hope this helps