HELP! Try solve this!

[rotamasta7]

Yamaha CV25 starts first time every time on the front lawn with the muffs on, which doesn’t even take a complete pull. Dropped it at Berowra last weekend and wouldn’t kick over, not a little puff of smoke or spark, took the plugs out, cleaned them, played with the kill switch, checked fuel, tried with fuel line out and obviously by then flooded real good. Popped it back up on the trailer and travelled home…
Got home, whacked on the muffs and first pull, she starts up fine… SPEWIN’, cracked the s**ts and didn’t look at the boat again til this weekend…
Walked outside, put the muffs on, first pull, fired up again, so thought… stuff it I’m ganna have another crack at Berowra… get down there drop her in, and she won’t start again, scratching my head I realised it won’t start in the water… pull her back out and first pull she fires up. So while it was still on trailer put shaft just in the water fired it up and launched the tinnie away. All day it works fine, fished for 2, 3 hours at a time before firing it up again first pull and moving around. Left it for 5 hours in the water, then went fishing at night and the engine again fired up first pull. Running great.
Tied her up over night, got up early in the morning to go fishing, started up after 2 pulls, was driving along for about 30, 45 seconds and CLOONK, she just died on me, couldn’t do anything to help it once we used the minn kota to get us back, cleaned the plugs and everything again, no go..
Got a tow back, back on the trailer, got home, put the muffs on and fired up first pull..

I’m scratching my head and so is everyone else around me… obviously I should just take it for a service which it had not too long ago, but trying to avoid the cost of it as I am a uni student…so any help would be MUCH appreciated.

[riverprawn]

I know bugger all but maybe too much pressure in fuel tank?

[rotamasta7]

I've had the little air value open....and don't worry mate by my description...you can tell i know bugger all either! haha

[JIM1]

i had something similar to this, its got something to do with low compression and low octane fuel and you cant give it enough of a kick to push water out of the exhaust, and get it to run on. if u get what i mean. i lift it up out of the water and it starts fine. 98 octance fuel and a spark plug one grade hotter could help if its a bit smokey, running rich and poor starting is where things usually start to go wrong first up

[rotamasta7]

Thanks Jim, I will give that idea a go, still wide open to all suggestions thought...anyone? really keen to try everything myself before dealing with a mechanic

[Bobby Bass]

What fuel do you use?
E10?
Regular unleaded 92?
Unleaded 95?
Premium 98?

[leachy]

It sounds like fuel to me. Does the priming bulb have pressure in it when it will not start, Have you checked the fuel line connections. I thought I had a problem once and the engine was missinging and carrying on and it was the connect into the motor. It seemed to be plugged in correctly but it wasn't.
Does it depnd on the fuel level in the tank?

Good luck, I am sure it has nothing to do with it being in the water though, there just to simple for that.

[JIM1]

could be good ol vapour lock, google it and it should have a remidy other than time

[Fishigan]

Plug in an old spark plug to one of your leads and get your mate to hold it. Crank it over and if your mate starts hurling abuse at you, you've got a fuel problem. Could be a vapour lock or a partially blocked carby or old fuel or choke sticking on.
If your mates still talking to you, there's an intermittent electrical problem. Could be a faulty stator, loose wiring, old plugs/leads etc

[JIM1]

Originally Posted by Fishigan

Plug in an old spark plug to one of your leads and get your mate to hold it. Crank it over and if your mate starts hurling abuse at you, you've got a fuel problem. Could be a vapour lock or a partially blocked carby or old fuel or choke sticking on.
If your mates still talking to you, there's an intermittent electrical problem. Could be a faulty stator, loose wiring, old plugs/leads etc

can always put the plug in the lead and where you put your spanner on it, put that bit on a nut somewhere on the motor to earth the check spark, or put your pinky in the lead and save the plug altogether:P

follow the fire trianlge, fuel/air/ignition. one of them goes the triangle tumbles!

[yellow door 1]

Originally Posted by rotamasta7

Yamaha CV25 starts first time every time on the front lawn with the muffs on, which doesn’t even take a complete pull. Dropped it at Berowra last weekend and wouldn’t kick over, not a little puff of smoke or spark, took the plugs out, cleaned them, played with the kill switch, checked fuel, tried with fuel line out and obviously by then flooded real good. Popped it back up on the trailer and travelled home…
Got home, whacked on the muffs and first pull, she starts up fine… SPEWIN’, cracked the s**ts and didn’t look at the boat again til this weekend…
Walked outside, put the muffs on, first pull, fired up again, so thought… stuff it I’m ganna have another crack at Berowra… get down there drop her in, and she won’t start again, scratching my head I realised it won’t start in the water… pull her back out and first pull she fires up. So while it was still on trailer put shaft just in the water fired it up and launched the tinnie away. All day it works fine, fished for 2, 3 hours at a time before firing it up again first pull and moving around. Left it for 5 hours in the water, then went fishing at night and the engine again fired up first pull. Running great.
Tied her up over night, got up early in the morning to go fishing, started up after 2 pulls, was driving along for about 30, 45 seconds and CLOONK, she just died on me, couldn’t do anything to help it once we used the minn kota to get us back, cleaned the plugs and everything again, no go..
Got a tow back, back on the trailer, got home, put the muffs on and fired up first pull..

I’m scratching my head and so is everyone else around me… obviously I should just take it for a service which it had not too long ago, but trying to avoid the cost of it as I am a uni student…so any help would be MUCH appreciated.

When ever things go bad - you expect the worst - which sometimes means you ignore the obvious.

When my engine was giving me intermittent drama's - I spent over a grand with various reputable "OMC Master Technicians" in lab coats and clipboards trying to work out why it kept stalling.

It took a 16 year old apprentice, to find a split O-Ring in my primer bulb. It had nothing to do with the engine and the problem could have been solved by spending $10 on a new bulb. Or 10c on a new O-Ring.

But it was a good life lesson........ - sometimes the reason your brand new TV stops working after a week - is because you knocked the aerial jack slightly out of its socket while doing the vacuuming

[Flyman1]

I had something similar to this happen on a 15hp Yammie I once owned. Try this. When dark but don't upset the neighbours start the motor on the muffs and see if there is a spark short occuring from the plugs and or ignition lead across to any other part of the motor. The motor still runs but if this is occuring it will be very obvious to see at night. My problem I eventually worked out was when I had the motor cover off and ran the motor on the muffs all went fine. Cover on motor would starte then died under revs. The problem eventually turned out to be that the ignition lead although looked OK was shorting out on the metal engine cover clip that holds the engine cover in place, but only when revved up a bit. To see if this may be your problem using some electrical tape, the good stuff, tape up the ignition lead and see what happens, as when taped up the short is unable to occur. If all runs fine under load replace the lead. See how you go and let us know what happens.

[BRETT]

if you have the muffs on there is water pressure from hose and when you put it in the water there is no pressure.. i'm wondering if there is a sensor that reads there's water so the water pump does'nt burn out and the pressure of the hose is making the sensor work... just a thought..

[leachy]

The CV 25 is to simple for water sensors, I have one myself. Its only got one carb and two cylinders and that about it.

Rotamasta7 when you do eventually start the motor is it real smokey, not just normal smokey like the CV is when it starts normally for the first time. Ifr it real smokey I would guess its a spark problem if no smoke or just the normal amount its a fuel problem.

Are you sure its not the cut out push button / safety switch.

Regards
Leachy

[harry1]

When you start your engine with the muffs is your engine trimmed up?