Outboard airlock?

Dyflin

Dyflin

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I can't seem to get my normally very reliable mariner 8hp outboard to start. It turns over for about a second and then cuts out. Have been through all the checks I can think of and everything looks ok. But I did notice that there were some air bubbles coming out of the water intake at the base of the leg at one stage. Is it possible some sort of air lock is causing the problem and if so what should I do?

Thanks in advance!
 
No!

You should be checking the plugs and for sparks at them. If you get a good juicy spark then start looking for fuel / carburetter problems
 
An air lock" type "problem you could have, is the breather or vent in the fuel cap. Check it,s clear ,cos if it aint thats the sympton you,l get.Like VicS said ,first job make sure you,ve got a good spark. If so ,step 2 drain or clean out the float bowl. Step3 if you have to go there, strip carb and clean jets.When you say normally reliable, has it been stood a while, or has the sympyom just arrived
?
 
It's been sitting idle for about two weeks but normally this isn't a problem. Checked connections and all seemed ok but bubbles out of cooling water intake made me wonder...
 
Don,t get it about bubbles? Do you mean after you,ve been pulling (the outboard I mean)till your red in the face ,then tilt it up to, get respite and renewed strength.Is the moment said bubbles are present? /forums/images/graemlins/confused.gif
 
I think it was midway in one of a series of marathon chord pulling sessions that all these bubbles came out. Can't seem to recreate the effect now.
 
Glad your bubbles have burst. Rule of thumb with outboards. If She don,t go ring de dingy after 3/4 pulls summats up. Then the more you pull the worse it gets . You get knackered, and sometimes the engine. So back to basics. Whip the plug ,or get a new un, clean it see if you have spark. Just drain the carb for now. Fuel on, let the bowl fill cos you,ve drained it. Chocke on 3/4 pulls, if nothing DONT pull any more cos summats up. Have a fag or brew go back ,try half choke same routine, if nothing summats definateley up.Yor gonner tell me "I,ve already done that, smart arse" Yeh I know but do it again, proccess of elimination. Lets presume for now that theres not much up, in which case the aformentioned will tell us. /forums/images/graemlins/wink.gif
 
The bubbles are just the exhaust, not burnt hydro carbons in this case, but just the air you've drawn in being pushed out where they should be pushed out.
If there's enough fuel in the float chamber to supply the main jet then it should run for at least 20 seconds until the float chamber empties.
So I'd say electrics are the problem.
Maybe just a new spark plug will do the trick. Cleaning plugs has never worked since they started putting sulphur and all sorts of stuff in fuel.

Other wise it sounds like a breakdown in the HT side, at which point I'd wheel it down to the mechanic.
 
[ QUOTE ]
It turns over for about a second

[/ QUOTE ] Is it really firing and running briefly. If not and you can get no spark check the stop button and its wiring.
 
If it fires it's not electrical. I'd go with the "drain the float bowl" option. Sounds like water in the bowl.

Do check that when you remove the (obvious) drain screw, that you lift and rotate the engine so that it CAN drain. Yamaha Maltas have the drain facing uphill, so I always (usually, sometimes) check this rigorously.
 
I would try everything that others have said but if that fails you may need to check the stator coil. Mine (same engine) packed up a couple of years ago. One minute it was fine. Then it stopped (luckily we were on the mooring).

Now the bad news. A new one cost £100. Sorry! /forums/images/graemlins/frown.gif
 
Can't agree with that. It may manage a couple of cycles and break down. That's always the worst fault to find. Usually means replacing everything in the system.
 
Without trying to sound funny but did you check you had turned the fuel ON. I had a similar problem with my merc - pulled and pulled and pulled - then realised I had not put the cutout "key" in so puts the key in and pulled and pulled and pulled and pulled and .... Get the picture?. Then the sprog comes up on deck and says "did you turn the fuel on?" Duh! forgot hadn't I. Fuel on and a few pulls later she was running fine. Smart arse sprog was then sent up the mast to check the contacts on the tricolour bulb.
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"Artificial intelligence is no match for natural stupidity"
 
Thanks for all the replies and advice.

I got all sorts of advice and assistance in the marina too. In the end, while someone was off routing out a plug spanner, I gave it a few more goes and eventually she fired up! Just before this, an awful lot of air came out the base of the leg somewhere in a big crescendo of bubbles and then a couple of pulls later she roared into life.

Had a terrific sail in Dublin bay afterwards and the engine (1977 mariner 8hp) fired up first time, every time, as usual.

While trying the internet for advice yesterday I came across this article which is probably just as good advice for a mechanical idiot like me /forums/images/graemlins/wink.gif

Outboard from hell
 
With the weather we're having for our bank holiday which is this weekend, I'd say yes! /forums/images/graemlins/laugh.gif
 
Bubbles

Nah!, that is just related to the air you are pumping down the leg to the exhaust outlet whilst trying to start it. Once started, the expanding exhaust gas makes far more bubbles.
 
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