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Old 09-10-2006, 09:37 AM   #1
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200 Promax over oiling and fouling plugs

Hi Guys,

Was wondering if anyone could shed some light on this problem.

The engine has had the automix system removed (properly) and relies on the oil being mixed with the fuel.

I have been mixing at 50:1, but this seems to foul the plugs really quite badly after a short amount of time.

For example, yesterday, I removed all the plugs, cleaned them thoroughly and replaced, dumped fuel I had and mixed up a new batch, 20L of fuel, 400ml of 2 stroke oil.

Ran the engine on the quayside for approx 20 mins, then took it for a quick blast up the river, on the way back, engine is sluggish at low revs, get back to pontoon and engine is unable to idle, kicking out lots of white/blue smoke, if I take throttle off completely, she'll die and not idle.

Took the plugs out again and they are completely coked up with oil.

The engine is a recent rebuild, I am sure it should be a 50:1 mix, but this is defying all logic, btw the engine runs perfectly at high revs.

Can anyone shed any light on this?

Best Regards
Chris
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Old 09-10-2006, 12:09 PM   #2
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why are you running it on the quays side for 20 mins itsd a performance engine and is meant to be ran hard
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Old 09-10-2006, 01:17 PM   #3
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Because we were trying to determine why so much oil was getting through to the plugs, it was not a small amount.

I appreciate it is a performance engine and it does run extremely well when at WOT, but it shouldn't die and smoke like a trooper when it's trying to idle.
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Old 09-10-2006, 02:05 PM   #4
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All the Guys i know that pre mix all smoke loads at idle and oil up. Dunno what you are worried about just switch off rather than idle
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Old 09-10-2006, 02:12 PM   #5
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Yeah, can appreciate that too, but it doesn't idle LOL It just dies and the plugs are all fouled and it misfires something chronic at low revs.
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Old 09-10-2006, 02:26 PM   #6
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sounds electrical
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Old 09-10-2006, 03:16 PM   #7
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Sounds electrical....how?

Sounds more like an air leak to me, have you checked all the joints around the area that the premix pump was located?

Cyco
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Old 09-10-2006, 03:31 PM   #8
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I have not, that is an interesting point, I'll check that this evening

Cheers Cyco

I'll also check cabling to the EFI as well.
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Old 09-10-2006, 03:43 PM   #9
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Quote:
Originally posted by Cyco
Sounds electrical....how?

Sounds more like an air leak to me, have you checked all the joints around the area that the premix pump was located?

Cyco
Didn't think of that, electrical being fueling properly at low revs
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Old 09-10-2006, 06:51 PM   #10
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Thumbs down Fuel pump

Quote:
Originally posted by Burty
Didn't think of that, electrical being fueling properly at low revs
Rob read the post.

Motor runs fine at WOT which would indicate that the pump is fine.

Look for air leaks around the inlet.

Cyco
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Old 09-10-2006, 06:59 PM   #11
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Cye read my post

I didn't say anything about a fuel pump.
I was on about the EFI system or ECU at low revs, maybe overfueling but as i said yours is a good idea
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Old 09-10-2006, 07:07 PM   #12
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Fight!!!
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Old 09-10-2006, 07:53 PM   #13
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*slowly backs out of the room before he's classed as a trouble maker*

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