help me i am new to this please

[madxbri]

ok all i finally found a site with some people that may be able to help me out <br />i am a small loch fisher and have just got a flat bottomed boat and a johnson 4.0 hp longshaft outboard engine i already worked out my boat needs a short shaft i was told this would not matter so in the wheelie bin it went now on this engine it has a fin above the propeller and one further up i filled with water upto the fin at the prop as the prop was coveverd with water and hay presto 2 pulls and it sprung into life no probs revved very well and ticked over in gear and in netrule <br />so on the boat it went and out to water it went <br />it wouldint tick over and was very slow to rev i noted the exahust outlet was now way under the water should this be above or bellow as i have no probs with being able to raise the motor up but to where should it sit at the bottom of the boat ect ?<br />i know this all sounds a bit novice but then i am and i know i should just buy a short shaft ect but just canot afford it just now <br />thanks all in advance <br />Brian

 

[roscoe]

Re: help me i am new to this please

The large fin (anti ventilation plate) just above the prop, should be about flush with the bottom of the boat. The exhaust should exit below the waterline.<br /><br />Precise positioning of the motor on the boat is not critical on a small rig such as yours.<br /><br />Does your engine have a built in gas tank, or does it use an external gas tank?<br /><br />If it has an external tank, try squeezing the primer bulb. Does it get firm? does it stay somewhat firm while the engine is running?<br />If not, try squeezing it while engine is running, and see it the engine picks up some.<br /><br />Other things to consider:<br />Has the engine been in storage for a long time? It may have accumulated dirt in the gas tank, carbeurator, or filter.<br /><br />Post the model number, serial number, and year of the motor, if possible.

 

[JB]

Re: help me i am new to this please

Howdy, MadXBri.<br /><br />You need to raise your engine so that the AV plate (horizontal plate above the prop) is even with, and parallel to the keel or bottom of your boat.<br /><br />A simple way to do this is to make up a plate of 2 laminated thicknesses of 2cm marine grade or pressure treated plywood and bolt it to the outside of your transom so that the top is about 5" (13cm) higher than the transom.<br /><br />Then you mount your long shaft engine on that.<br /><br />If you still have problems with idle speed, readjust it with the engine on the boat and in the water.<br /><br />Good luck.

 

[angus63]

Re: help me i am new to this please

The cavitation plate (horizontal plate above the prop) should be even or slightly (1-2")below the bottom of the boat. A 4 hp is not going to plane the boat (even a flat bottom). Just make sure the water intake is well in the water at all speeds (height won't effect speed much). You may need to use a spacer on the transom to raise the motor if she sits low enough to flood the exhaust.<br />PS- All of my relatives live in Ayr & Cumnuck. Say Hi for me.

 

[angus63]

Re: help me i am new to this please

You hear the echo JB, Roscoe?????????

 

[madxbri]

Re: help me i am new to this please

man that was fast ok firstly <br />ty for letting me know i can raise it i wasent sure now i know there is a good lump of wood under the fibreglass so no probs there <br /> the model number is aj4brlcde and has an onboard fuel tanks cant c it being dirt as it ran great on the bin ?<br />at the hight you sugested but not on the boat <br />no probs angus63 i shouted as loud as i can dont know if the heard tho i live up near inverness <br />so might not have lol<br />any one know what size engine will get my boat on the plain then ?<br />and what one would you sugest if any <br />thanks folks for all the help so fast <br />Brian

 

[angus63]

Re: help me i am new to this please

9.9 hp maybe will plane depending on lots of stuff.<br />15 hp I'm pretty sure will move you some.

 

[madxbri]

Re: help me i am new to this please

ok follow up i know you recon on a 9,9 hp but just found the plate and it says max 6 hp ?<br />i think it is a sniper tt overdraft i may be wrong but they look like original stikers <br />the boats year is 1989 <br />any one got any info on this as i am not keen on that big an engine if it says max 6hp and 4 people max ?<br />thanks again <br />Brian

 

[roscoe]

Re: help me i am new to this please

The design style and weight of the boat determines the hp needed to plane.<br />Some hull designs will not plane.<br /><br />A 7.5 hp planes my 12' nicely. It is an aluminum v hull.<br /><br />Your engine is a 1986 vintage.<br /><br />Good Luck, let us know how it works out.

 

[madxbri]

Re: help me i am new to this please

thanks for that info rosco <br />how did you find out what year the engine is as it was only bought by my father a few years ago and was ment to be new ?<br />as far as i know anyway ?<br />i will let you know tomorow as i am raising the engine tonight and will run it on the water tomorow <br />thanks again <br />Brian

 

[madxbri]

Re: help me i am new to this please

ok raised the motor no difrence <br />just runs a bit better when i give it full reves it dies but if i give it say nearly full reves and pull the choke out it reves very nicely then chokes ?<br />gave it new fuel and mix ect dose this sound like a faulty plug ect as it has two i know i should just change them but its not to easy to get new ones living in the scottish highlands <br />any one know what this could be ?<br />regards <br />Brian

 

[madxbri]

Re: help me i am new to this please

any one got some info or know of where i will get some for the typ of boat i have <br />thanks again <br />Brian

 

[roscoe]

Re: help me i am new to this please

It sounds like you need to clean/rebuild and re-adjust your carburator. Sounds like the jets may be restricted and the engine is running lean. Also clean out the gas tank and fuel line just to be sure you aren't drawing in any sediment.<br /><br />Highlands? How high above sealevel?<br />Over 400 meters above sealevel?<br /><br />I knew the year by looking at the model number that you posted.<br /><br />The "CD" designates the year.<br />C = 8<br />D = 6<br />1986<br /><br />Sorry, I can't find any info on the net that pertains to your boat. It sounds as it is not a hull that is designed to plane. But if you get the 4 hp running properly, it should move you along, perhaps up to 10 kpm.

 

[madxbri]

Re: help me i am new to this please

all this info is great sea leavel it was tryd on a very calm part of the sea <br />i was out yesterday and it will now run clear <br />withought the use of the choke ect but seams as tho it is reving up then dieing a little as if its strugling had a look at the plugs the look fine anyone know if number one plug is top or bottom incase these have bn changed around ?<br />the leads are numberd but im not sure if this may be the fault will it run with the leads round the wrong way ?<br />thanks all <br />Brian<br />ps i think i will strip it all out and have a look at the carb ect help on the leads would be great

 

[madxbri]

Re: help me i am new to this please

ah i nearly forgot i beleave this is the mixer screw the one next to the full on of and choke it will ony run if the one next to the choke is turnt way round to full why would this be anyone know if i turn it down the engine just dies on me ? should this happen ?<br />thanks again <br />Brian

 

[dakotashooter2]

Re: help me i am new to this please

You don't mention the size of your boat. I have run 6HP motors on several 12' V and flat hull aluminum boats and they have always planed. I have also seen a 3 HP plane similar sized boats. Does your motor have any trim adjustment (to adjust angle of motor on transom) on the mounting bracket? The mixer screw is your low speed jet. Try pulling the knob off, turn the srew clockwise until it stops (keep track of how many full and partial turns it takes just in case)then turn counterclockwise 1 1/4 to 1 1/2 turns and put the knob back on in the center position (if possible). Start the motor and see how it runs. Adjust in 1/4 turn incriments to fine tune. Other posibilities may be a blockage in the fuel delivery system (lines, filter or pump) or closed vent hole on the tank (usually on the fill cap). If none of this works a carb cleaning/rebuild is probably in order.

 

[madxbri]

Re: help me i am new to this please

Hi thanks for the info i wasent sure if that was a mix screw ill try that also my boat is about 10 or ll foot and 4 foot wide very light two of us can carry it for distance no probs but my motor seams as tho it is realy strugling all the time i bought the flat bottom well its a typ of flat i think you would call it a v hull as it has ridges outside and one in the middle it says on the boat that it takes a max 6hp engine so i thought a 4hp would nip it along but its more like a slow crawl ok strip down of carb is on the cards anything i should watch out for ?<br />i have done alot of 2 stroke bike carbs is this the same and any idea if this will run underpowerd if the plug leads are the wrong way round ie number one lead on number 2 plug ?<br />thanks again <br />Brian

 

[Paul Moir]

Re: help me i am new to this please

If you got the plug wires backwards, the engine will never start. It will just occasionally backfire. Sounds to me like this thread is starting to belong in the engine repair forum. To me it sounds as if one cylinder isn't firing. You could try alternatly removing the spark plug wires and see if it runs any different to confirm this.<br />BTW - I regularly run an overweight 16' aluminum boat off of a 5hp. I once had an experience that sounds like yours running a johnny 4hp on a 12' light Al boat. It was running on one cylinder.

 

[Maximerc]

Re: help me i am new to this please

had a 3 hp Johnson 1955 vintage on a 12 ft john boat .. Alum ..very light it would plane .. if you sat in the middle of the boat it would clip right along.if you sat in the back ya had to lean forward with both legs ahead of the seat. thought it would be fun to put it on my 8 ft minimost (plywood Hydro) It not only would not plane it would barly move. but stuff like that is just fun to try