Exaust fumes

Clyde_Wanderer

Clyde_Wanderer

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Have a Perkins 3 cyl, 10306 engine and after a hour or so running I am getting quite strong exaust/engine breather fumes smells in engine compartment and adjoined lockers and under cockpit sole etc.
I can not find an exaust leak but think the fumes are comming from crank case breather tube which comes from the rocker cover.
Should this tube run to an outside vent or is there any way of preventing its associated fumes/smells, bearing in mind these engines were originally designed for small plant ie Kobota mini excavaters etc.
C_W
 
VicS said:
No provision to connect the breather to the air intake ???
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Fraid not filter is a K&N flat pan type with foam strip filter which gets clogged up regurlarly with rubber dust from a misaligned alternator belt which I will sort when she gets lifted out for winter.
I am considering fitting an alternative filter arrangement to which I could possibly fit a tail to take breather tube.
Would this cause any combustion problems if breather connected into air intake?
Thanks. C_W
 
Clyde_Wanderer said:
Fraid not filter is a K&N flat pan type with foam strip filter which gets clogged up regurlarly with rubber dust from a misaligned alternator belt which I will sort when she gets lifted out for winter.
I am considering fitting an alternative filter arrangement to which I could possibly fit a tail to take breather tube.
Would this cause any combustion problems if breather connected into air intake?
Thanks. C_W
Click to expand...

No, crankcase breather tubes are often led into the air filter box.
 
FullCircle said:
No, crankcase breather tubes are often led into the air filter box.
Click to expand...

Hi FC,

I'd tend to offer up a breather pipe just in front of the filter box intake pipe/opening rather than put it directly into the casing of the filter box.

Some engines are manufactured with breather pipes going directly in but they may have done 'exhaustive' testing with pipe bore size etc..to ensure they are not sucking out at too great a pressure.

What do you reckon?
S.
 
These breather pipes used to vent to atmosphere, but nowadays are fed into air intake to lessen emissions etc

So to see if that is where the fumes are coming from, extend the hose to downwind side of cockpit and run the engine for a while?

You should not really have exhaust fumes coming out there tho, unless you have blow by at piston rings

Is there much pressure coming out the end of the existing hose?
 
bikedaft said:
Is there much pressure coming out the end of the existing hose?
Click to expand...

There shouldn't be a lot of crankcase pressure on a healthy triple since crankcase volume changes relatively little as the engine cycles (unlike singles and most twins). Put a fingertip to the hose and you should be able to feel a distinct pulsing rather than a continuous pressure to atmosphere. Any gas expelled should smell oily/enginey but not overpoweringly of exhaust gases which would be indicative of blow-by. Apart from anything else, the latter are of course poisonous, although a quick diagnostic whiff shouldn't do any great harm.
 
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What is it, Exhaust or Breather? The two are quite different. Breather fumes are actually lub oil mist and the smell will be sweet and becoming more sickly and acrid as it gets hotter. Exhaust fumes are far more vicious on the senses, mild to strong sulphur smell depending on fuel quality. Leaves a metallic taste in the mouth and will take your breath away whilst drying the throat if you take a deep breath of it. If it is breather fumes you can sometimes get little filters that fit over the breather. Car modifying shops might be the best source, Demon Tweeks etc.
If its exhaust, you have a leak.
 
Actually while on the subject and as mentioned above, I would like to change intake filter type to something like frying pan shape or cylinderical shape which I could mount further back in the engine compertment but could not find anything suitable the last time I looked.
Anyone suggest where I would get an old mini etc type? and would paper element filter be suitable for marine use?
Thanks. C_W
 
Best bet after market car filters come in all shapes and sizes. Online or motor factor. Don't see why you couldn't use paper element, but most seem to have a washable sponge type element
 
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