Spark plug insights
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Hooked
px 200 e
Joined: 08 May 2013
Posts: 115
Location: australia
Mon Sep 07, 2020 3:07 am quote
Hi all

Noticing a lot of oil on the thread of my plug ( px 200 ) and colour on ceramic seems to be ďone sidedĒ. Wondering what ideas people have on reasons for.

Also getting a bit of black greasy goop around exhaust stub meeting muffler point but thought this is pretty regular. [/img]

B1499E41-C7B3-4699-96A1-2BEC0C6362AE.jpeg

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P200 VNB Li125
Joined: 28 May 2008
Posts: 4439
Location: Hustletown, TX
Tue Sep 08, 2020 8:44 am quote
note ... I am a bumbling, wannabe mechanic... and I know even less about tuning. That said, that plug looks way to wet on the threads.

What jets are you running? Are you getting good throttle response all the way through the power band or are you getting spluttering/sputtering somewhere?

The black soot on the engine is generally pretty typlical of 2 strokes. Maybe take some pics of the area (and/or tighten the the bolt at the exhaust stub) so we can see what it looks like.
Hooked
px 200 e
Joined: 08 May 2013
Posts: 115
Location: australia
Tue Sep 08, 2020 12:47 pm quote
Thanks for reply
Iím running standard jets - though 118 main jet cause hole is drilled on air box.
Bike doesnít splutter, seemed to run well though I canít seem to get any faster than 90km/h. ( itís a 1996 px 200 ).
I recently cleaned all the black goop after tightening air box and tweaking cylinder head bolts but havnt managed a long ride since.

As mentioned bike does run ok so maybe i shouldnít be concerned.
Thanks again for you opinion.
Hooked
px 200 e
Joined: 08 May 2013
Posts: 115
Location: australia
Tue Sep 08, 2020 12:48 pm quote
Note correction - tightening exhaust stub.
Hooked
1981 P200E / 1979 P200E / 1974 Rally 200
Joined: 30 Jul 2009
Posts: 456
Location: San Francisco, CA
Thu Sep 10, 2020 4:02 pm quote
offhand, looks like a leak? Like maybe the plug was not tight enough, or there's some debris interfering with the seating.

I have the same slimy goo leaking out of the exhaust header. The clamp doesn't really seal it off, but also clear that there's fuel/oil that isn't combusting. Maybe that's just natural, though.
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7958
Location: Victoria, Australia
Thu Sep 10, 2020 6:44 pm quote
Re: Spark plug insights
gujuk wrote:
...colour on ceramic seems to be ďone sidedĒ.
That's because the offset, angled spark plug position means that the plug is not equally exposed to the mixture. So (I imagine) it burns quite cleanly facing the piston and not so much on the 'shielded' side.

Molto Verboso
2007 Stella 150
Joined: 02 Nov 2019
Posts: 1114
Location: Rochester, Minnesota
Sat Sep 12, 2020 3:02 am quote
For your top speed. What do you have for an exhaust pipe? Iíve heard the pipes with a catalytic converter arenít the best and choke the bike. If you donít have an aftermarket pipe maybe look at that to help with top speed. Also maybe the pipe is old and getting clogged. It would also help to know what maximum rpm youíre getting to.
Hooked
px 200 e
Joined: 08 May 2013
Posts: 115
Location: australia
Sun Sep 13, 2020 2:59 am quote
Thanks for replies.

Some insight from ginch makes sense.

Christopher
Iíve got a 96 bike with stock pipe. Yes might be a little old. No converter on it. Donít know how Iíd figure RPM out...

And hjo Iím going with it a bit normal with the goop situation and will give it a clean from time to time.

Iíve checked timing with timing light and itís set to the A mark which I think is 23 degrees BTDC. I think this is the setting for a 96 px though some people have different opinion.
A friend has suggested I retard it by a little to 22 or 21 degrees amd it will likely give me a little more power at top speed and make it run just that little bit cooler at WOT.

Might look at adjusting it and seeing what it feels / runs like!

Thanks all again for chiming in.
Ossessionato
1963 VBB2T
Joined: 07 Nov 2012
Posts: 2284

Sun Sep 13, 2020 5:29 am quote
Re: Spark plug insights
Ginch wrote:
gujuk wrote:
...colour on ceramic seems to be ďone sidedĒ.
That's because the offset, angled spark plug position means that the plug is not equally exposed to the mixture. So (I imagine) it burns quite cleanly facing the piston and not so much on the 'shielded' side.

This would sound like the most reasonable explanation with the plug reading the way it does on one side.
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