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Spark plug colour - oxide red?

Craigorypeck - 15/2/11 at 10:13 AM

Ideas?? doesn't look like any of the pics in my haynes manual..

MakeEverything - 15/2/11 at 10:19 AM

I would suggest that its getting too hot.

Mr Whippy - 15/2/11 at 10:19 AM

I'd say overheating but I've never seen such a bright red colour like that. Have you been leaning out the mixture?

Wondering if you have been using an additive like redex? Have you been leaning out the mixture?

do you put copper grease on the threads? doing that will lower the plug temperature quite a bit

[Edited on 15/2/11 by Mr Whippy]

Mr Whippy - 15/2/11 at 10:23 AM

noticing the red colour of the engine, is there paint in the inlet ports? just wondering if disolved paint pigment has stained the plug??

gavin174 - 15/2/11 at 10:32 AM

found this...

http://www.verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm

doesnt look like your plug is on it thou..

might help some one in the future.

Craigorypeck - 15/2/11 at 10:38 AM

AH... it may be the octane booster stuff I put in...! Should have thought.
Afrs are 14 at idle, 12 at wot and 15.5 on cruise.
All the plugs are like this except no one cylinder which is grey/black, and looking down into the cylinder there is a puddle of oil...
mixed with the tear I shed when looking in LOL!
So I'm thinking and oil stem seal?? I remember when building I put one seal on and forgot to put the spring platform on first so it may have been damaged during removal and replacement.. Cant remember which cylinder but at a guess its this one.. Head off.

Strontium Dog - 15/2/11 at 10:40 AM

I've seen this a few times and it has always been put down to additives in the fuel or octane boosters. This can be the additives in ordinary 95RON fuel from Tescos or any other supplier for that matter. It might be manganese but that is just a theory, not something I know to be correct. Should not be a problem as long as there are no other witnesses on the plug of tracking, heat etc. Where do you get your fuel out of interest?

If you try a different source, the deposits should burn off after a couple of fills and then try your regular garage again!

Oh, and your afr on cruise is a bit lean too IMO

[Edited on 15/2/11 by Strontium Dog]

Mr Whippy - 15/2/11 at 10:44 AM

you can change the stem seal without taking the head off. turn the engine till the piston is at the bottom and feed in thin rope, then turn the engine round by hand which compresses the rope against the cyclinder head trapping the valve. You can then use a make shift valve compressor lever to remove the collet and spring

Compressor levers look like this or make you own from some tube and bar

Craigorypeck - 15/2/11 at 01:24 PM

Cheers for the tips!
I went a lot of miles to find super unleaded and was still having a pinking issue so bunged in some octane boost too and still have pinking... Cant get it rev on any decent sort of ignition timing .. ?

Having trouble getting cruise afr nearer to 14, I think I really need to try different profile needles in my bike carbs..

Mr Whippy - 15/2/11 at 01:55 PM

quote:
Originally posted by Craigorypeck
Cheers for the tips!
I went a lot of miles to find super unleaded and was still having a pinking issue so bunged in some octane boost too and still have pinking... Cant get it rev on any decent sort of ignition timing .. ?

Having trouble getting cruise afr nearer to 14, I think I really need to try different profile needles in my bike carbs..

Perhaps your compression ratio is too high or your plug runs to hot. Maybe try a cooler plug or put copper grease on the threads)

Don't know how many miles are on that plug but it's is sooooo clean it's worrying should have some deposits on it even after a shortish drive

[Edited on 15/2/11 by Mr Whippy]

westf27 - 15/2/11 at 02:12 PM

Looks like red diesel

Mr Whippy - 15/2/11 at 02:33 PM

quote:
Originally posted by westf27
Looks like red diesel

maybe he's been running it on blood!!

Craigorypeck - 15/2/11 at 05:06 PM

See this is where I'm stumped!!! I have a CR of 10.8:1 so that is not very high..

Timing is correct ie, when idle at 18 degrees and a fancy timing light with -18 I'm bang on TDC mark.

To get the engine to hit 5000rpm without pinking I have wot ignition timing way back to 23 degrees?? This will burn the crap out of the exhaust valves Ive been told.

I'm running NGK BCR 8ES plugs which most NA YB run, even burtons suggested them... But I will try some copper grease on them too

Will oil seeping into the cylinder via the dodgy valve seal cause pinking?? It the only thing I can think thats not allowing proper advance up the rev range.

Took the head off anyway to get a decent look at whats going on, 2 3 4 are dry and black 1 is oily.

Plugs have 150 miles blood free miles since the engines been built..

paulf - 15/2/11 at 09:23 PM

When I had a cross flow in my car I found that manganese based valve seat protector and octane booster caused a reddish rusty deposit on the plugs and exhaust.
Oil in one cylinder will cause pinking , I had a zetec that had oil visible in bores looking through the plug holes and even after changing the stem seals still used oil but never found out where it was getting in.
Paul

Craigorypeck - 15/2/11 at 09:47 PM

quote:
Originally posted by paulf
When I had a cross flow in my car I found that manganese based valve seat protector and octane booster caused a reddish rusty deposit on the plugs and exhaust.
Oil in one cylinder will cause pinking , I had a zetec that had oil visible in bores looking through the plug holes and even after changing the stem seals still used oil but never found out where it was getting in.
Paul

I hope the new seals fix my problem.... I know more when posty arrives with a burtons prezzy.. I'll report back with results, hopefully good..