Running on one of twins...

[gray duck]

really blows. Fortunately I was just taking the family on a harbor cruise when my FIL asks what it would be like with just one engine. I had been meaning to try this anyways so I pulled one up and tried to get out of the hole. No WAAAYYYYY! Very relevant post given the san diego capsize of the defiance with mono/spectra on one prop - see general parker forum. What do people think/do etc? I can't see how a 25 hp kicker could do ANYTHING with a 2520 loaded down and in some seas and wind. A single of twins might do a little better with a different prop but who's gonna change it if the seas are bad?

 

[BradV]

its to get home only at idle speed. i have tried to plane with my 225 and not a chance. If you want to get home at any kind of speed you need to get a spare set of props at a lower pitch. There is a possibility that an engine can stop working in calm conditions as well so its one of those things on how prepared do you want to be and feel comfortable without being. I keep spare props only when going to the islands because we fish within 5 miles of shore 99 percent of the time in one of the most popular boating places. Spare Props are the ones that came on the boat. I thought about getting smaller pitch but now id be carrying 2k in spare props. Not sure the boat would plane out with the loads i typically run with even with a smaller prop especially bahama loads. obviously the story you are referring to is a combination of bad things that happened. Its amazing how things go wrong out there and how quick they happen even if youre prepared and experienced. Long story...

 

[pmeggers]

A kicker for safety reasons is really on worthwhile if you got a single engine on the back....

I was out on a yellowfin a couple years back with twins, we were about 95 offshore and hit a submerged log, only one prop barely usable...limped back in doing between 4-8 knots given the wave, current. you do the math --- pure evil

 

[John_Madison CT]

I have a single OB on my 2520DV, but back it up with a Yamaha 9.9hp High Thrust kicker.

Sure, it's not nearly as good as having another V6 OB on the back, but it's a great emergency engine that can keep you moving, up to 6.5 knots..

I also use it for trolling sometimes. It sips fuel.

 

[grouperjim]

......what Brad said.


even if you could get up on plane with the remaining good engine, if you don't have the spare lower pitch prop, you need to consider the damage from lugging the engine versus just idling in and being late.

no doubt if there is an approaching storm or other hazard to avoid, then go for some speed with the good engine.

 

[gray duck]

I am amazed that your 9.9 can deliver 6.5 kts! That really is a KICKER! It felt like my 150 couldn't make us go that fast by itself. My reason for wanting speed with one engine is purely for weather/safety.

 

[BradV]

Get another set of props. You can probably find a cheaper set of aluminum props. But not sure how well they would hold up. Stinks to have to carry 2 spare props especially when it will only be for one.

On another note it does not require much hp to move a boat at displacement speeds. That is why you see 50' trawlers displacing 60,000lbs and 135 hp engines. Then see a 50' sportfish that planes out with several thousand hp motors. Talked to a guy running a 60' Viking the other day said he burns 200 gph at cruise of mid 20 knots and Wot was low 30s and 250+gph. Twin 2000hp motors.

Gray duck did you have the tabs all the way deployed? did you have anyone go sit on the front of the boat? My friends boss with a 34 Venture can plane on 1 250 but he has monster kplane tabs and everyone has to move to the front. Then once youre on plane you can let people go wherever because you dont need as much hp to stay on plane. hes also spinning 17 pitch props so they arent as aggressive. Maybe with smaller diameter props you would have a chance too.

 

[DaleH]

I am amazed that your 9.9 can deliver 6.5 kts!

Me too, though it appears to be physically possible.

Theoretical hullspeed (knots) = 1.34 times the square root of the hull length at the waterline.

Hullspeed or displacement speed is limited due to the formation of the bow wave (FYI - that's why you see huge tankers having the 'bulbous' bow to break the bow wave). It takes POWER to achieve planing speeds, which gets you over the bow wave.

Assume 23' waterline length, sr-rt of 23 = ~4.8, so 4.8 * 1.34 = 6.432 knots.

I can't comment on a 9.9hp kicker's ability to do that, but if a high thrust model (low pitch prop with lots of motor torque) run off a bracket (clear water), in calm seas, then I could see it getting close ...

 

[John_Madison CT]

I have the Hi-Torque model Yamaha 9.9hp kicker. It's very low pitch, huge surface area.

Bear in mind that I'm testing in Saltwater, LI Sound to be specific, so there could be tidal influences at play.

I'll back peddle a little and say 6 mph no problem. I remember seeing that on my GPS many times.

 

[MacFern]

I have an 8hp kicker on my 2320 and needed it a while back. I was going against a strong outgoing tide, and 15-20 knot winds. I made it a few miles (in a couple hours), but as the weather picked up I eventually started losing ground. Ended up picking a different ramp just to get in. Might be a good idea to try out your kickers in some nasty weather so you'll known what to expect when/if you need to really use them.

 

[Bryan 2530]

I frequently start only one engine to run back into the rip, especially if it is a nice calm night. I don't plane the boat obviously but I make sufficient headway. Doesn't seem to stress the engine at all.

 

[grouperjim]

definitely.

........occasionally i drive a 31 island runner out of Pompano/Jupiter. always using one engine to reposition to save hours.

 

[Porkchunker]

I almost always reposition up wind from breaking fish with one engine. I get good control and if needed could run that way for many hours.

I once wrapped an entire 9wt fly line around a prop at the CBBT. It was winter and I certainly wasn't going to lean over the motor bracket and try to remove a prop when the water temps were about 46 deg. and the air temps were about 34 deg. So I limped back to Little Creek NAB on one motor...a distance of about 8 mi. I backed the boat to the ramp, put on my hip waders, and removed the prop and the line...then went back out fishing. The trip back on one motor was boring, but otherwise a successful endeavor.

I tried once to get up on plane with one engine, and failed miserably. I was thinking about getting a cheap aluminum prop in a lower pitch for a test to see if I could get up on plane with one...but haven't yet bothered. Guess I should complete my test someday.

Dave

aka

 

[Aircoastie]

I just put a 9.9 kicker on my 2320 tied in to the main, electric trim with a second set on controls in the pilot house. I know it won't do much in horrible weather, but I only go offshore when the wx is decent and worst case scenario I can keep the bow into the seas until it lays down or I have some assistance.

After loosing a fuel pump on the 225 to ethanol last year, I figured it was time for some backup as I fish the rigs out of Venice, LA and I can be 30-40 miles out in over 5000 feet of water.

I would love a twin, but for the next few years this gives me 75% the saftey and a bit of piece of mind.

 

[gray duck]

Dale - thanks for the calculation - I'm guessing that should be our most fuel efficient cruising/trolling speed and the next most efficient would be planing. (?)

Brad - I didn't have the tabs down all the way and people were in the back - I'll try your suggestions next time.

 

[jethro]

really blows. Fortunately I was just taking the family on a harbor cruise when my FIL asks what it would be like with just one engine. I had been meaning to try this anyways so I pulled one up and tried to get out of the hole. No WAAAYYYYY! Very relevant post given the san diego capsize of the defiance with mono/spectra on one prop - see general parker forum. What do people think/do etc? I can't see how a 25 hp kicker could do ANYTHING with a 2520 loaded down and in some seas and wind. A single of twins might do a little better with a different prop but who's gonna change it if the seas are bad?

It is a good thing that the motor you were running on is still in one piece. Four strokes have high compression ratios and are very susceptible to detonation. Trying to get a twin powered boat onto plane, or running it on plane if you can get it to, can be very harmful to the motor. You were lugging the heck out of the one motor. Lugging leads to detonation and detonation can destroy a motor in just a few seconds.

With some engines the engine makers can now see throttle position via a sensor and the computer logs engine RPM. If they see a WOT condition and the engine RPM is not in the upper half of the WOT RPM range they know that the engine was being abused. Most warranties will not cover a failure that results from abuse.

 

[gray duck]

jethro - thanks for the info. you're scarin me though. I think everything is OK - we only went a lil bit and I didn't have the hammer down - now I know not to try. thanks

 

[mlc20]

Just a thought when running 1 engine do you guys tilt the other engine up or leave it tilted down. not sure if it creates drag or anything but interested in seeing if it makes a difference, either slowing the boat down or making it faster.

 

[pmeggers]

youre going to want to trim the non-running engine up

 

[Bryan 2530]

Check out the end of this video.

http://www.youtube.com/watch?v=4W4P9adkV5o