9HP Merc - Sustained daily useage ??

[watercruiser]

I am thinking of running my 27' sailboat (7000lb) the complete ICW run (1000 miles approx).<br />Looking at my options, financially and practically, apart from investing in a 4 stroke 15+ HP. Or similar.<br /><br />No I'm not gonna put in inboard in the boat !<br /><br />How would you see a well maintained 2 stroke 9HP outboard holding up under sustained useage approx 6 hours per day ?<br />Is it simply too much or do I have a chance ?<br />It runs great in the bay but that's only to get out there and back.<br />I need to hit 5 knts min alll the way to make deadlines for anchorages and bridges etc.<br />Bear in mind it's mainly a river, with some areas of current.<br />Any wise advice appreciated.<br />Skipper.

 

[Chinewalker]

Re: 9HP Merc - Sustained daily useage ??

If it's propped correctly for the load (a low pitch sailboat prop), and the motor is otherwise healthy, then there shouldn't be a problem. I'd also consider installing a new impeller if the current one has been in there for a few seasons... A new set of spark plugs might not be a bad idea, either...<br /><br />- Scott

 

[Solittle]

Re: 9HP Merc - Sustained daily useage ??

Carry a spare set of plugs, extra prop and perhaps a shop manual and you should do just fine. If you have to do a lot of long time slow running you might want to decarb before you leave.

 

[rodbolt]

Re: 9HP Merc - Sustained daily useage ??

propped correctly I see no problems running the 9 or 15 HP for 6 hours at a time. what kind of RPM will you have to turn to keep it at 5Knts? also if your going to push it hard then maintain it hard. dont think if the wind is free everything else outta be <br /> had to toss in one blow boat joke .<br /> I have some of the larger 4 strokes that spend 4-6 hours at a time above 5000 RPM with no issues.

 

[roscoe]

Re: 9HP Merc - Sustained daily useage ??

Its a sailboat, right?<br />So whats the motor for?

 

[watercruiser]

Re: 9HP Merc - Sustained daily useage ??

Appreciate the advice especially those stink potters "Go Boaters" <br />Thanks.<br />I wouldn't know the exact RPM but I guess I'm about 75% of max revs. Once the boat is moving she's happy to trot. I anticipate some heavier load during mooring and currents but not every minute.<br />In terms of oil mix, whilst attempting on getting it right, I assume leaner keeps the carbon deposit down, but the engine burns hotter correct and richer will gum up the plugs etc? So exact mix is best ? <br /><br />Cheers.<br />Roscoe the motor is much less fun but it get's me down the river

 

[watercruiser]

Re: 9HP Merc - Sustained daily useage ??

At a general attempt, what would you say the GPH will be on a 9HP pushing the sailboat?<br />I plan on trials next few weeks, using GPS for DOG & SOG. I am hopeful in guessing slightly below 1 GPH ?

 

[Paul Moir]

Re: 9HP Merc - Sustained daily useage ??

In calm weather I'll be suprised if you need more than 1/2 throttle to sustain boat speed. So you should expect under 1GPH. Normally with outboards the fuel consumption goes way up in the last 1/3rd or 1/4 of the throttle.<br /><br />Mix correctly, and if you err, err on the side of caution is my rule for little engines. They generally handle over-oiling well. If carbon is a problem (it shouldn't be as long as you go beyond 1/2 throttle normally and the engine is propped correctly) use a fuel treatment (Seafoam, OMC Engine Tuner, Yamaha whatever-its-name-is, Merc you-get-the-idea).<br /><br />The critical thing is to prop it correctly. If it's overpropped very bad things will happen in short time. Carbon (coke) builds up and sticks the rings to their grooves, which then scratch the bore walls. The entire engine gets very hot sometimes causing preignition resulting in severe engine damage. Correctly propped engines rarely need decarbing.<br /><br />I strongly recommend having a manual of some sort for your engine aboard, so if the need arises you can quickly fix it. I would pick up an extra impeller and keep it with your tools since you can blow one of these out by picking up a bag or whatever en route. I don't know how clean your ICWs are, but I lost one last year to a large piece of kelp. But that all depends though on wether you're the sort of person that would haul their engine into the cabin to effect repairs.