Whats wrong.....

Brad Y · #1 23-12-2007, 07:20 AM

Its happened twice now.

I am going along in my boat and the motor just dies. No warning no nothing. It happened whilst prefishing for the albany gf two weeks before the event. Nothing was found to be wrong so I took it out the weekend of prefish ban and it went flawlessly. Albany grand final yep flawlessly.

Today I started in a couple of km off busselton looking for a bonito or two to jig up and it started fine and got me to where i wanted to go but thats it. By the time sea search and rescue got to me I was 8 miles out. Yep thats twice i have been towed in by sea search and rescue groups.

To get more technical on the problem, the motor dies and will turn over but wont fire. Its getting fuel (and no Im not flooding it, I have checked that) It seems to only happen when the motor is warm, as each time I have got it home and it starts fine from cold when I flush it out. Again there is fuel flow through the fuel filter- I took that off and checked it out on the water) But no matter what I do, it just turns over and doesnt fire. It dies from WOT- no coughs or splutters just dies as if someone pulled the lanyard.

What is wrong with it??

toadfish · #2 23-12-2007, 07:13 PM

have seen in moto-cross bikes(not boats i know!)kill switch problems as you have stated.Even brand new bikes that stop for no reason!My boating skills are poor to say the least but sounds electrical to me!

Brad Y · #3 23-12-2007, 07:31 PM

Yeah i was contemplating the killswitch mechanism. Im taking it to the merc place today to spend a whole day suggesting things and testing. Main problem is that its fine when you start it, it has to be over extended running so it gets up to temperature. Not so easy to replicate in the workshop.

So far my limited internet research has mentioned

stator
sensors
coils
Trigger on switch base
Timing and to go over all the cables.

Logically I will be going to start with leads and plugs and working my way into more technical stuff. Glad theres a mechanic coming in for me....

Leethal · #4 26-12-2007, 08:07 PM

CDI (capacitor discharge ignition??) box died on mine (55hp 2st johnno). Was going along fine then nothing. Would turn over fine but no spark. You could hold a plug lead and turn it over and nothing at all

It didn't work after you cooled it off though. You may just have a dodgy box that dies when it's warm??

cleetus · #5 27-12-2007, 01:10 AM

Quote:

CDI (capacitor discharge ignition??)

That was my first thought to Brad. Unfortunately you have to wait till it dies to be sure. Maybe get a hairdrier on the unit while running the motor in a bin of water? I had a Dr250 dirt bike that did the same. It would run again if a put a g clamp on it! Sudden stops are usually electrical so if you can narrow down the testable components like the kill switch etc you should be able to eliminate what it isn't and end up with a small list of possibilities
hth

Rosie · #6 27-12-2007, 07:36 AM

My 8 hp Merc had a bunch of people stumped and it turned out to be the kill switch earthing out. I was about to fork out for a new CDI when it died at the mechanics and they found the switch to be the prop. Kill switches often create a circuit which stops the engine and we found it by unplugging the switch so the curcuit was discontinued.

Good Luck with it, Ben

Brad Y · #7 27-12-2007, 09:18 AM

We found it to be the stator coil under the flywheel not putting out enough voltage. Replaced that on christmas eve- thanks to Augusta Marine for bringing in their mechanic and letting me use their workshop on short notice. Seems to be working fine. Though now I have a pin connector on the harness not making connection. Im a whisker away from cutting my losses and changing outboards belive me....