Author Topic: Fouling plug  (Read 2120 times)

Offline mickwinf

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Fouling plug
« on: May 01, 2013, 06:13:37 PM »
I have a problem with spark plugs. After being stood for a few days without being used my 500/4 is a bit reluctant to start, then only fires on 3 cys, number 2 wont fire. If I remove the plug it is wet and wont spark, a new plug and away it goes! This has happened a few times now, the bike runs great once going, timing spot on, all plugs are new NGKs carbs set and balanced, new filters etc. I am a bit stuck for what to check next?
Love the 500 and 550 have a 500 called Lazarus under restoration

Offline matthewmosse

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Re: Fouling plug
« Reply #1 on: May 01, 2013, 06:39:02 PM »
Plug cap or ht lead? does the plug work OK if swapped to another cilinder?
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock

Offline Paull

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Re: Fouling plug
« Reply #2 on: May 01, 2013, 07:46:38 PM »
If this happens every time it stands still I would agree with caps and leads but add reg/rec check.

I do warn you NGK plug are not as good as they could be, 2 in 10 new plugs go in the bin.  :(

Paull
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Offline mickwinf

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Re: Fouling plug
« Reply #3 on: May 01, 2013, 10:23:09 PM »
caps and leads are new, I replaced coil because duff plug fooled me into thinking coil was u/s. I also checked compression, 125psi.Why reg/rec? battery holds charge ok.
Love the 500 and 550 have a 500 called Lazarus under restoration

Offline Paull

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Re: Fouling plug
« Reply #4 on: May 08, 2013, 10:14:50 AM »
Sorry for late reply.

Reg can brake down and over power the plugs burning the diode out.

Just make sure the correct voltage is coming out of it.

 Paull
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Online deltarider

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Re: Fouling plug
« Reply #5 on: May 08, 2013, 03:54:11 PM »
Quote
Reg can brake down and over power the plugs burning the diode out.
?
BTW, my 500 starts within a blink next day after being used, two days later still perfect, three days later still OK, but... when bike has stood for 5 days or more it is hard to start. Nothing to do with battery charge (checked this), nothing to do with gas or carbs (checked this too).
Suggestions anyone?
« Last Edit: May 08, 2013, 03:58:42 PM by deltarider »

Offline Bryanj

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Re: Fouling plug
« Reply #6 on: May 09, 2013, 07:47:20 AM »
Plugs don't have a diode

 

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