Newbie - Covered in oil and petrol !!!

gtturbo · 30 March 2014, 19:31

Well ! I have bought a Yamaha 28a and a Zodiac 3.8m mk2.

To cut a long story short this 28a is a DOG to cold start. Vent open , choke out , tiller to start and a bit more, Adonis pulling the started , 25 times later we are away.

I took it for its maiden voyage to Ullswater , how great it was , for 20 mins, then it stopped for 2 hours whist I diagnosed the problem - bad quick release fuel connector - removed it , dipped the cable into the tank and were away again.

Once home I put the engine in the wheelie bin , (not to throw away) and filled it with H2O. I was letting it get cold and trying to start more efficiently over a few days.

I had read - PRIME PRIME PRIME - so i primed , i pumped the primer so it was hard ( i had read that a carb would not over fill and would stop once full) but it made little difference , it started eventually but it was hard - once its warm its easy.

The trouble is , I have squeezed that darn primer bulb so much my carb no longer stops the flow of fuel - i kept squeezing and it kept filling - the wheelie bin water ran with fuel and it was well and truely flooded. Now covered in fuel and a little worried i have broke the engine I detached the fuel line - drained the carb (check me out) and cleaned the spark plugs - after 10 more tries It started again - albeit rattly , smokey and fast.

I let it run for a bit and it settled - I attached the fuel line and things change - it doesnt want to idle and wants to cut out - the blue smoke starts getting thicker. I take the fuel line off and it settles and the blue smoke slows.

I think that there is something wrong with the Carb - it seems to be stuck open (i dont know if thats possible but it would make sense , i dont even know what a carb does ) - anyway - its in this state now !

What on gods green earth do i do with it ! and does my diagnosis make sense . Im hoping there is a quick fix to wack a valve into place on the carb so i cannot over fill in the future - plus the blue smoke bad tick over problem.

Any advice for a novice trying to learn a bit about the dark arts of outboards !

diver 1 · 30 March 2014, 20:25

May I suggest step 1 might be to get a clean plastic fuel can, fill it with totally fresh fuel from the petrol station, add the right mix of marine 2 stroke oil - being sure to get the mix right for your engine - and trying it then. It's amazing what difference fresh decent quality fuel can make! Maybe try a whole different fuel container, hose, bulb and connector. - perhaps you can borrow one off a mate or another boat for a few mins. That will dismiss possible poor fuel, air leaks, etc before you start looking at anything more onerous! Good luck.

bartiny · 30 March 2014, 20:56

Hi, it is possible to pump the priming bulb too much you can overcome the float valve resulting in flooding, stop pumping when the bulb gets firm not rock hard.

With my 25hp 2 stroke Mariner I pull out the choke, turn tiller to start, give it one good pull (99 times out of 100 it will fire but not run), push choke back in and then it very rarely fails to start the next pull.

Check spark plugs gap and clean, and if fitted check points and check timing.

HTH Good luck

gtturbo · 30 March 2014, 20:57

Hi Diver

I have only had the boat and engine about 5 days and the fuel is fresh from then , totally empty clean tank , oil @ 75.1 , rather then the 100.1 due to the age of the engine 30 od years.

Prior to me over filling the carb with the primer it was working fine - except the hard start in the cold.

Its only since I flooded the carb that the blue smoke and poor timing has occured

I truely believe that I have managed to break the carb or something - just dont have a clue what to do about it !

Im thinking it might have to go in for a pro to look at - i want it up and running for over easter !

A1an · 30 March 2014, 21:03

I'm reckoning you have blown the fuel pump diaphram and you are now pumping fuel into the crankcase, hence the rough running with loads of smoke and unburnt fuel in the bin.

Take the fuel pump off and check the diaphram nearest the engine.

Been there done that.

bartiny · 30 March 2014, 21:05

Quote:

Originally Posted by gtturbo

Hi Diver

I have only had the boat and engine about 5 days and the fuel is fresh from then , totally empty clean tank , oil @ 75.1 , rather then the 100.1 due to the age of the engine 30 od years.

Prior to me over filling the carb with the primer it was working fine - except the hard start in the cold.

Its only since I flooded the carb that the blue smoke and poor timing has occured

I truely believe that I have managed to break the carb or something - just dont have a clue what to do about it !

Im thinking it might have to go in for a pro to look at - i want it up and running for over easter !

In my opinion you have flooded the engine so it will smoke and run rough whilst it gets rid of the excess fuel.
Going off what you say I cannot see any way that you could have damaged the carb.

gtturbo · 30 March 2014, 21:29

Thanks for all the responses guys -

There was alot of fuel in the bin water - i left it running for 15 mins , hoping to clean it out and get back to normal but no cigar.

I have give up for today , im sure next door was getting sick of me revving the engine and cursing .

Before the "change" happened I could not over prime the carb , it sayed solid and was rock hard - it was only after me over doing it that it suddenly became weak and i can pump for england ! It does firm up , but nothing like before.

How easy is it to take the carb off and clean up the valve ?

I will also check the diaphram , I have no idea where the fuel pump is , do ancient yamaha engines have them - it would make sense as there was alot of fuel in the bin water - enough that I put the chimnea out in the opposite corner of the garden , cos if a spark had found its way into that wheely bin I would not be writing this - far too much for just flooding

I never had an issue with the spark plugs and they are new - but inthe last 15 mins running with this problem , they were black and oily.

So its sounding like either some carb voodoo , or fuel diaphram wickedness.

A1an · 30 March 2014, 21:42

I THINK your pump should look like the picture below.

Take it off, it's just two bolts, block the OUT spigot with your finger and blow into the IN spigot, if you can keep blowing then your pump is shafted.

bartiny · 30 March 2014, 21:50

Quote:

Originally Posted by A1an

I THINK your pump should look like the picture below.

Take it off, it's just two bolts, block the OUT spigot with your finger and blow into the IN spigot, if you can keep blowing then your pump is shafted.

If that was the case then the engine would not run after the carb bowl had emptied as the pump would not work.

But for what it is I suppose its worth checking.

peterwhite · 30 March 2014, 21:52

If I were you I'd change the fuel pump diaphragms (should be done as part of a service anyway) and clean the carb out properly any your engine will run much better. There is no need to prime and prime the bulb. You shouldn't squeeze it so hard all it needs to be is firm as the carb is full and if clean and set right the engine should start without too much difficulty.

A1an · 30 March 2014, 21:55

Quote:

Originally Posted by bartiny

If that was the case then the engine would not run after the carb bowl had emptied as the pump would not work.

But for what it is I suppose its worth checking.

I had EXACTLY the same thing on a Yam 75AET, it would supply enough fuel to the carbs but small amounts were being sucked into the crankcase through the pumps vacuum port.

simon23 · 30 March 2014, 22:00

I don't want to put a downer on you, but it wasn't running right before you 'broke' it.i spent weekend after weekend messing around saying I'm sure its something simple and getting no where.if you can get the cash together give it to the man who knows,pay him and enjoy your boating.

gtturbo · 30 March 2014, 22:22

well - I risked divorce and nipped out the the shed to see my nemesis once more

I whipped out a size 9 wrench and took off the fuel filter

I can confirm that if you blow into it , air comes out of the side closest to the engine. I take it that it has a hole that shouldnt be there

The engine did struggle to run when idling I had to speed up the idle a few turns to keep it going - im thinking it must just be a small hole....

if this is it , i will get some diaphrams from ebay or some where and replace -

Muchos Gracias everyone - you are outboard gurus

gtturbo · 30 March 2014, 22:43

I would usually take it somewhere - but............ this thing is old old , its a relic - about the same ages as me , 1978 era

I want to know a bit more about it myself , just so I feel confident if something daft happens I know what to check etc.

The fuel diaphram is defo split as per picture - the pump itself if coroded and a screw is seized so im going to replace the unit.

Obviously this may well lead me back to square one with a bad cold start.....but thats not too bad.... it does start just makes hard work of it....

maybe with the new pump and a carb clean , a bit of practice i will get a quicker less time consuming start..........

A1an · 31 March 2014, 06:46

That's your problem right there.

I actually have a couple of those skins on my spares shelf just incase, I would offer to send you one but you are going to need a whole new pump by the sound of it.

Don't be so hard on the bulb next time

gtturbo · 31 March 2014, 09:23

Thank A1an. I have ordered a pump and hopefully it will be here by Wed.
Thanks for the advice , I would certainly not have known to check that , but I will in future.

beamishken · 31 March 2014, 18:54

If its any conciliation I had a 28hp yam a few years ago & it was a cracking little engine when it was going so probably worth persevering with
I also had a pump diaphragm fail on an 85 yam & it ran fine at high rpm but was rough at tickover which sounds a bit like the fault you have
so sounds like your on the right track

simon23 · 31 March 2014, 19:04

I had a couple of 28e's think they may be the same as yours but with electric start, same as above great motor ,only downside was quoted £35 for a set of points from the mariner dealer, luckily didn't have any in Stock. Got some from the yamaha dealer for the bargain price of £13 per set! !!

RIB-Teccie · 31 March 2014, 19:05

If you have ordered a fuel pump you will probably need the gasket between it and the block.

Couple of tips.

1. Remove fuel pump pipe going to carbs. Place finger over it. Squeeze bulb. If you can still prime the bulb (assuming it is in good condition) the chances are the diaphragm is holed. To make sure, repeat test with pump removed and if fuel squirts out if the middle hole it's definitely holed.

2. Attach fuel line directly to carb and squeeze bulb, of the fuel squirts out of the carb breather or out if the carb air intake, your float is set too high or the needle valve us worn or stuck open.

The 28a is a super engine. It's bad points were the bottom crank seal and bad corrosion problems where the water pump attaches to the gearbox. The condenser can play up also.

9D280 · 02 April 2014, 12:43

While you are getting spares - a set of new spark plugs can make a huge difference to the running.

The fact you have unburnt fuel in your bin might hint that one cyl is acting more like a premix pump than a power source.

I had similar with an old 55 of similar vintage to yours. After I changed the plugs (& as it turns out the HT leads) I gave them to a spark mate to see what his Megger thought - one of them would have failed a PAT test!