Small outboard cuts out

I

isandell

Well-Known Member
Joined
1 Mar 2003
Messages
308
Visit site
I have a Suzuki DT 2.2. It is about 15 years ago, lightly used, alway reliable as long as new fule is used, and serviced every year, not that there is much to do.

Last summer, it began stopping after a few minutes running, less at full high revs. It would start readily after about a minute but not before. Classic signs of fuel starvation I thought.

I have stripped the fuel system, thoroughly cleaned everything and replaced fuel tap, as the seal was starting break up. No improvement.

I find that the fuel flow with the engine stopped and the carb drain screw removed is about 50ml per minute. With the engine running at about cruise revs, the flow is 10ml per minute and the engine cuts out iafter about 1 minute. Turning fuel off immediately the engine stops, I find the float chamber is near full.

So it does not seem to be fuel starvation - what else can it be?

Any suggestions welcome.

Ian
 
I read somewhere recently (probably here) of an engine stopping (possibly) due to breathing it's own exhaust, due to leaking. Try running with the cover off to check.
 
I have just been thinking about spark plug. It's not the behaviour I would associate with spark plug but I am off to motor factor to get new one.

Ian
 
Head gasket, before you fit another you need to true your old head up by rubbing it on a sheet of wet and dry on a sheet of glass. Common problem on single cylinder water cooled outboards.
 
I would have diagnosed a fuel problem but that seems to have been eliminated. Time therefore to look at the ignition.

If it slowly dies I'd still consider a fuel problem but if it suddenly stops dead more likely to be an ignition problem.

Worth spraying some fuel mix into the carb throat when it stops and trying to start again it immediately. If it fires and runs briefly its worth taking yet another look at the carb and fuel system, otherwise check the spark.
 
Sometimes possible to spot a head gasket problem by the fact that you may see small bubbles coming from head to block join when the engine warms up if it's been breached. Spark plug should also tell you.
 
steve66 said:
Its a head gasket problem!!
Click to expand...

Probably not.
But if it is, you should feel a lack of compression when trying to start it.
I suspect either water in the fuel, corrosion of a small jet or passage in the carb, or the ignition.
A half mm drop of water is enough to block the idle jet in some of these little carbs.
I would give the ignition the best possible chance by fitting a new NGK plug of the correct type.
If you can put a strobe light on it when it refuses to start, it should show if it's sparking.
 
lw395 said:
Probably not.
But if it is, you should feel a lack of compression when trying to start it.
I suspect either water in the fuel, corrosion of a small jet or passage in the carb, or the ignition.
A half mm drop of water is enough to block the idle jet in some of these little carbs.
I would give the ignition the best possible chance by fitting a new NGK plug of the correct type.
If you can put a strobe light on it when it refuses to start, it should show if it's sparking.
Click to expand...

You can't necessarily feel the lack of compression with a head failure . Mostly it will slow down and not tick over due to water in the cylinder on the induction stroke
These engines don't have a slow running jet, they are a slide carb. A screw raises or lowers the slide. The op says he has stripped the fuel system so cant be water in the bowl. The ignition on these is cdi usually they either work or not.
Only passing on the benefit of my experience of repairing single cylinder small outboards and these and 2hp johnson evinrudes are prone for it. I have repaired dozens. Word of warning make sure before replacing the gasket you make sure you flat the head and don't use the old gasket
 
steve66 said:
Head gasket, before you fit another you need to true your old head up by rubbing it on a sheet of wet and dry on a sheet of glass. Common problem on single cylinder water cooled outboards.
Click to expand...

steve66 said:
Its a head gasket problem!!
Click to expand...

VicS said:
Thats already been suggested as a possibility earlier in the thread
Click to expand...
Yep steve66 suggested it earlier but probably felt left out as no one came back to either agree with him or tell him he was talking a load of bølløx.
 
Last edited:
Might sound dumb but have you got the fuel tap in open position. I had same engine and in a few days absent mindedness was trying to use it with tap closed, despite using it previously for 3 seasons. The symbol wasn't very clear.
 
steve66 said:
You can't necessarily feel the lack of compression with a head failure . Mostly it will slow down and not tick over due to water in the cylinder on the induction stroke
These engines don't have a slow running jet, they are a slide carb. A screw raises or lowers the slide. The op says he has stripped the fuel system so cant be water in the bowl. The ignition on these is cdi usually they either work or not.
Only passing on the benefit of my experience of repairing single cylinder small outboards and these and 2hp johnson evinrudes are prone for it. I have repaired dozens. Word of warning make sure before replacing the gasket you make sure you flat the head and don't use the old gasket
Click to expand...
Usually, if there is a lack of compression due to rings or minor head leak, it will run if you can start it.
Suzi CDI does not have the best rep, it has been known to fail in such a way that a few minute running warms it enough to stop.
They used to call their system 'pointless' in the 80s :-)

You could be right, but I've seen enough grumpy outboards to know that water in the carb or damp in the electrics are prime suspects.
Could also be float level/needle valve making it too rich?

Does the plug come out wet when it dies?

Perhaps it just don't go 'cos it ain't a Yamaha.
 
You must log in or register to reply here.

Share this page

Top