guy to check engine/shaft alignment

[ekenna]

Can anyone suggest a guy to check my engine/shaft alignment? My boat seems to be underpowered which has gotten my in trouble twice this summer. Both times was in 20 knots winds. Once trying to get out of knapps narrow which almost wreaked the boat. The other time was a saturday in sept with 2 foot waves. I could not make head way with the way I normally run the engine.
I normally only get 3.5 knots motoring in no wind situation (per gps)

So I put the boat up for sale and last saturday 2 guys came to see it. Both said the 11 hp 5411 universal engine should be enough to power the boat but maybe the shaft is not aligned so it is not getting full power.


The boat is 28foot san juan 22 ft lwl 6200 displacement.
The boat docs mention these props with these engines
atomic 4: 14 X 6 RH
volvo 7a: 14 X 9 LH
yanmar YS 12: 14 X 10 RH
yanmar QM 15: 14 X 14 RH
(Question is the 14 in "14 X 6" 14 inches? if so maybe I just have the wrong prosize because the prior owner say it was a 12 inch prop)


The universal 5411 has 31 cu in 2.68 bore 2.76 stroke with 11 hp at 3000 rpm.It is not one of the engines mentioned but it is supposed to be close to the atomic 4.

Of course this 3000 rpm raises an interesting point. The boat has no tach so I do not know how fast it is running. It also has no water temp (long story I got it working once after I originally overheated it but then over heated it again when replacing the impeller)
So I tend to go light on it so not to risk overheating again. I let the guy that really interested in the boat play with the engine a bit and he ran it faster than I do. I has occassionaly run it faster in short bursts like if I touched bottom and want to back off but I general do not run it that fast long term. Am I just not giving it enough fuel?

Anyhow does anyone know someone who knows about this stuff? If it is just a matter of realigning the engine/shaft or maybe a new prop to get 5 knots then I will keep the boat.

On a side note if I clean off the water temp sender again is there a special trick like filling the hole with water before you close it up that will help get it working again? when I pulled it out I did not see and water in the hole and the sensor is covered with black carbon build up.

[chef2sail]

This does not sound like an alignment problem. Sounds like you have engine issues. My old Atomic 4 driven Islander 28 was rated at 30 hp not the 11 your Universal is, however I dont think the reduction in hp would prevent you from achieving at least 6 knots in flat water.. 3 knts on the gps..with or against the current? (Thats a speed over ground measurement not necessarily speed through the water. Has it always been this slow in the water? or has this gradually happened over the course of the summer?.

..I would strongly suggest you get a good mechanic to go over the engiine with you as you have presented a myriad of problem areas.

Is the Univeral (Kubota) fitted with a Hurth transmission? Is their a reduction gear for the deisel? Atomic 4 do not need one but diesels which have one and replace them need a larger prop than the Atomic 4 had. Did they do the engine replacement correctly?

Are the prop and shaft clean?...the bottom?. If I remember correctly you bought the boat this year and splashed it in the Northern Chesapeake in the spring. Was the bottom painted. Have you had it cleaned during the summer at all. There will be lots of gowth on it if you havent. Tha will slow you to a crawl.

Was the boat surveyed when you got it? My surveyor checked on the size of the prop vs the engine. Is it pitched correctly?

Troubling is that you are overheating. Is the thermostat functioning? These engines are particular to operating in the 140-160 degree range..is that where you are. Is there scale in the engine blocking the water flow.

Overheating...thermostat...black soot on the sensor,,etc.Does the engone blow any type of smoke..grey, white, bluish, black?.

Does it have a mixing elbow which may be full of carbon?. How do you know it is running at 3000 rpm with no tach. Running at 3000rpm is pretty high.

You need a professional to go over your engine with you. Let a professional look at this before giving up your ship.

Dave

[MacGyverRI]

Originally Posted by ekenna

The boat docs mention these props with these engines
atomic 4: 14 X 6 RH
volvo 7a: 14 X 9 LH
yanmar YS 12: 14 X 10 RH
yanmar QM 15: 14 X 14 RH
(Question is the 14 in "14 X 6" 14 inches? if so maybe I just have the wrong prosize because the prior owner say it was a 12 inch prop)

Alignment wouldn't slow you down unless the shaft is rubbing so hard on the tube or cutlass that it would actually grind through it.

Props are easy to understand (sometimes)

1st number is the diameter in inches.
2nd number is how far the prop "should" drive the boat under ideal conditions in inches w/ 1 revolution of the shaft. (i.e. only in clay would this actually work)

a 14 x 6 would theoretically be 2/3's as fast as a 14" x 9" at the same RPM's on the same boat.

Too big of a prop, like 14 x 16", would just bog the engine right down.

[ekenna]

Chef2sail
True the GSP is over ground but when I said 3.5 knots I was talking current neutral. The boat has always behaved the same since I bought it in june 2009.
The prop and shaft were clean when I launch in spring. I did bottom paint the boat in spring. I know where you are going with it getting slower ie under growth. The boat was also pulled and powerwashed in july.

The engine has a transmission but I am not sure of the make. I’ll check that out on Saturday when I pump the holding tank so they call pull it. It is a raw water only so no thermostat. The first time I over heated it I was trying to get the boat to move faster and I kept inching the throttle up and was not watching the water temp gauge and the engine eventually sputtered and died. Then the gauge did not work. Then over the winter I cleaned the sender sensor and put it back in and it worked. I replaced the impellar on the water pump and tested it successfully before launch by putting the water intake in a bucket. However after launch the intake line must have had air in it because it wasn’t sucking the water through. By the time I realized that it was too late and the gauge was broken again. I cleaned the sensor again but it did not help. I think the engine is supposed to run at 165 degrees.

As far as smoke, I think you would describe the smoke at startup as grey but that is when I have gotten the engine running stable and look over the side to be sure the water is spurting out. I am not sure what you mean by a mixing elbow. I do have to say that the prior owner used to use starter fluid and so did I last season until I replaced the glow plugs. I know that is not really good on the engine and may explain carbon build up. By isn’t the water temperature sender supposed to measure the temperature of water is shouldn’t it have water on the other side of the hole it screws into?


The boat has not been surveyed. I have no idea if the engine replacement was done correctly. Actually I do not know what was in the boat before this engine. And as you say I have no idea if the prop is matched correctly to the engine or just what was on the boat from the prior engine (more likely the later). Who would I go to for this kind of information?

As for the 3000rpm. I have no idea what rpm I am running at without a tach. The 3000 rpm is off a engine spec sheet that explicitly say 11hp @3000 rpm. I do not think I normally run the engine anywhere near that.

MacGyverRI
Thanks for the information

[RichH]

Agree with the others about alignment.

Simple questions: what is you engine RPM at max. throttle????? Check the engine manual (horsepower vs. rpm curve) and if the engine is not at the peak rpm (power curve) at max. throttle, then the engine is 'lugging' at lower rpm and not able to develop maximum horsepower. If the engine rpm cannot reach close to its max. the engine will never develop its full horsepower.
The correction is to change the prop pitch so that the engine can develop 'near' its maximum rpm when under load.

Most sailboats are 'underpitched' which causes the engine to 'lug' (never developing max. rpm). Lugging causes extreme combustion chamber pressures which can lead to 'shortened' engine life ... can also cause bent piston connecting rods, hammered piston wrist-pins and hammered engine main bearings.

With a clean hull and correctly tightened (cool running) stuffing box. run the boat at max. throttle and record engine rpm ... take this data and the prop to a 'prop shop' and get the prop 'repitched' so that the engine can rotate at near is spec. maximum rpm. If you dont have an accurate or calibrated tachometer, get a cheapy handheld laser 'indirect' tachometer from amazon.com, etc. and use it to determine the 'crankshaft' rpm.

I state again, If the engine cant come 'close' to its spec. maximum rpm it will never develop its maximum horsepower.

[ekenna]

Per the "engine manual (horsepower vs. rpm curve) " it is 11 HP at 3000 rpm. According to the curve it should be over 10 HP starting about 2500 rpm and the max torque is about 1900 rpm at 21 foot lbs. The graph does not go beyond 3000 rpm. So does that mean 3000rpm is the red line ie don't go beyond? I do not have a tach so telling the exact RPM is difficult. Ill check out the handheld tachometer. I do know this. If I run the engine at full throttle it will quickly overheat.

[CalebD]

My friend who keeps his boat in the Rhode River uses a mechanic named Will Sibley.
Sid Smith Sr. might also be able to help you. He has some you tube videos.

[Janssen]

You would be surprised that many boaters want to believe that they have engine, transmission, and others costly problems with a vessel that cannot get out of its own way. When the only problem is a fouled prop!

It only takes a few weeks here on the Chesapeake for a prop to become fouled with barnacles. When you have an half inch of barnacle growth on each side of your prop blade- a small sailboat prop will just spin water.

I see it all the time at the Old Bay Marina travelift - boaters request an engine inspection and the marina owner says to simply check to see if the prop is clean - in almost all cases - the prop is loaded up with barnacles and a once barnacle free - the engine "problems" go away.

Next spring, I am having the marina apply a coating of Prop Speed to my prop and shaft. They are offering a free Prop Speed coating with haul winter storage this month and this is the only coating that seems to really work.

George

[Capnblu]

If you have carbon build up on your water temp. sensor,... you either have a real big problem, or you are not looking at the water temp sensor, or someone managed to insert a water temp sensor where it ought not go. Any way you slice it, get a mechanic to look it over, unless money is no object, then have fun learning.

[ekenna]

I have been away for the forum because of first winterizing the boat and then work. Someone suggested I talk to a prop shop. Does anyone know of a prop shop? Since the boat is on blocks for the winter I measures the prop and it is 12 inches. The manual for the boat suggests several 14 inch props but with different engine configurations. I need to know if for this boat and engine should I get a bigger prop?

I do not think barnacles explain the 3.5 knot speed. The reason I say this is because the boat was pulled in july and it did not have barnacles on the prop or the bottom. However when it was pulled in july they pressure washed it and I think it took all the bottom paint off. It is loaded with barnacles on the prop and the bottom. I did notice it was very slugish the last 2 times we went out in sept so those barnacle attached after july. I guess I should have put another coat of bottom paint on before they laucnhed it in july.

I need to work on the water temp thing.