Exhaust valve colour query

andeebee · Nov 27, 2017

Im treating the bike to a front end strip down clean / service and on removing the exhaust noticed the colour of one of the exhaust valves was very sooty compared to the others.
2008 GSA Stock exhaust and air filter.

I havent taken the plugs out yet or checked the valve clearances (todo list) but was wondering if anyone had seen this before? Tight gap on that valve possibly?

Sooty

Sweep

Other side

beaver · Nov 27, 2017

More like valve stem seal? (assuming they have these?) although it does look like its running rich on that one valve??... is it the lower one?.. oil in the bottom of the pot (rings)... Not sure what a tight valve would look like from the back.. guess it should be white as it will burn?

Smug · Nov 27, 2017

Are the plugs firing correctly?

Bendy toy · Nov 27, 2017

The "good" ones look very white (weak mixture). Check the clearances and the ignition coils. Miss firing primary coils will make that cylinder run rich.

andeebee · Dec 1, 2017

So next step in investigation led me to the coils

On removing I found the primaries in very good condition (probably new) and the secondaries a bit worse for wear.

Have been trying to measure them with a multimeter using various guides but cant get a reading from any of the coils.
Tried searching the forum for a guide but cant find one other than the 'check coils when engine running' versions.

Is there any way to check the coils using a multimeter? I tried this link but Im getting 0's everywhere so I must be doing something wrong :nenau

.

beaver · Dec 1, 2017

are you getting a spark from all of them??

andeebee · Dec 1, 2017

Cant tell, bike in bits so cant run it. I guess I could reassemble and try it then, just thought I could test the stick coils for resistance.

DrFarkoff · Dec 2, 2017

"White" Valves .

That is very LEAN running

Probably the effect of modern Emissions regulations

But White also Means hot! and if that is a 1200 Its weird how the only valve with the correct exhaust colour is the one you think is wrong!

andeebee · Dec 2, 2017

Good point DrF and I would agree the odd one out is the colour exhaust valve I have seen in previous IC engines. Yes, its a '08 1200 GSA.
I run the bike regularly on a 15 mile motorway commute using Tesco 99 RON Super fuel. The O2 sensors were, unsurprisingly, not sooty.
I wouldnt say the bike is the most performant I have had, but its my first R1200 so I dont know any different.

Maybe the O2 sensors are reading too rich so leaning up the mixture? But how does that explain the odd one out (valve)? Do the coils get a per valve setting?

Back to my original query - can the coils be tested across the pins to establish if they are good?

andeebee · Dec 2, 2017

After some farting about I found I had the multimeter in the wrong range for the pin 1 to 3 test. Now set mm to 200 ohms.
Im now reading 1.4 on all coils across pins 1 and 3 with one secondary coil reading 1.5.
Cant find any readings from Pin 2 to the plug socket though. Expecting to find a reading around 17.5 kohms with neg probe in the plug end but nothing.

Bendy toy · Dec 2, 2017

Your primary coils look like the later type with stainless steel sleeve. Chances are they are fine.
The bike will run fine with secondary coils disconnected though tickover might be lumpy.
The OEM fuelling map runs the engine on a very weak mixture. Low throttle can see 20:1. Exhaust and intake mods can make it even worse. Free flow headers; free flow exhaust; free flow air filter. Two of the three ok. All three not ok.
Check all valve clearances - both exhausts should have near enough the same gap. Otherwise the one opening first will take all of the gas flow.
It’s also possible or the oil seal has failed on the dark valve.

andeebee · Dec 2, 2017

Thanks Bendy makes sense.
Im waiting on a thin wall plug socket to come through post and then I will be onto valve gap checking.
I was due to fit a decat header setup, looks like Im going to need a plug in mixture fooling device and add loads of fuel otherwise I will be running leaner then Mo Farah on race day.
Will report back with valve gap findings.

Bendy toy · Dec 2, 2017

Decat header and fancy silencer can is fine the ECU will adapt. It won’t cope if you also add fancy air filter and/or shorten the air intake pipe.

The exhaust gas runs very hot with OEM map. Posh petrol helps because the earlier firing spark extracts more heat.

The options are a pair of AF-XIED lambda shifters or a remap. You could try a Power Commander but it’s a only ever a bodge and needs a rolling road to do properly.
The Hilltop remap makes spark timing and fuelling adjustments all the way over the rev/ throttle range. The Lambda shifter is a value across the whole range that can be adjusted.
Both options have their fans. It’s hard to say if one beats the other.

Pukmeister · Dec 2, 2017

andeebee said:
Back to my original query - can the coils be tested across the pins to establish if they are good?

Yes, and No: You can measure coil primary and secondary winding resistance but it is no guarantee that a coil is good. (Primary winding to earth, secondary to earth, three wires in the connector as earth is common and IIRC you need to have polarity correct or you get no resistance, I can't remember the values off hand. If you measure zero reverse the test lead polarity and retest.) Coils often break down when under load but seem fine with a meter.

My lower coils tested fine when cold but were as rusty and bulging as yours appear to be. Fitting brand new lower coils has massively transformed both the power, feel and smoothness of my 2008 GSA. Where it was a bit fluffy previously, it now runs beautifully crisp and the connection between throttle hand and rear tyre now feels like it should be, the difference is night and day.

In hindsight, I had been riding around the coil problem for ages.

£159 well spent IMO.

Bendy toy · Dec 4, 2017

Pukmeister said:
Yes, and No: You can measure coil primary and secondary winding resistance but it is no guarantee that a coil is good. (Primary winding to earth, secondary to earth, three wires in the connector as earth is common and IIRC you need to have polarity correct or you get no resistance, I can't remember the values off hand. If you measure zero reverse the test lead polarity and retest.) Coils often break down when under load but seem fine with a meter.

My lower coils tested fine when cold but were as rusty and bulging as yours appear to be. Fitting brand new lower coils has massively transformed both the power, feel and smoothness of my 2008 GSA. Where it was a bit fluffy previously, it now runs beautifully crisp and the connection between throttle hand and rear tyre now feels like it should be, the difference is night and day.

In hindsight, I had been riding around the coil problem for ages.

£159 well spent IMO.

That's quite possibly the case with mine but probably has been the entire time I've had the bike. The secondary plugs have the correct colour but its likely their coils are not firing smoothly. Main coils were replaced when they packed up. Smelling burnt was a big hint.

Exhaust valve colour query

andeebee

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