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Both sides spark plugs are black; looks like my mixture is too rich!


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Posted

I removed the plugs to be able to turn the engine easily, and I noticed they were very black. Which normally indicates the mixture is rich.

Anyone else with black spark plugs in their V11?

I guess there is not much that can be done, besides the recommended injection tune up. But even if my TPS and injection circuit are perfects, the ECU mapping may need something 100+ degF and humidity compensation.

Every day we are most between 105 and 110 F....

Posted

The ETS is notoriously fickle as it sits in a plastic holder and usually has an air gap between its tip and the base of the holder meaning it gives a shitty reading. You can, with care, add some sort of thermal paste beneath the sensor but one has to be careful as it can expand and crack the holder. If you can replacing the holder with one of the brass ones used on machines like the Daytona and Sport-I and packing that with paste is a safer option but a full tune up and ascertaining if the ETS signal is even remotely right would be the first port of call.

Posted

I have had quite the opposite outcomes, here, in our ridiculously high ambient temperatures of the US south. I found the ETS/holder material to "heat sink" in these environs. 

Once it got hot, it would not give up on the idea.

Rather like an unnamed lady I once had a relationship with . . . :whistle:

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  • Haha 3
Posted

Weak spark can sometimes look like richness.

I flunked geography,lol, are you in an area with dry heat or is it the type of high heat with lots of salty humidity that could cause corrosion issues on electrical connections?

Main ground & other connections might be worth looking at.

fwiw 

 

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Posted

Another stupid question.....What is the ETS?

Art

Posted

Thanks for the suggestions;

I will start with the easy solutions first, then move on if I can't get it resolved.

I will go spark plugs first, and Engine Temperature Sensor thereafter.

Posted
On 8/29/2023 at 10:34 AM, p6x said:

I removed the plugs to be able to turn the engine easily, and I noticed they were very black. Which normally indicates the mixture is rich.

Anyone else with black spark plugs in their V11?

I guess there is not much that can be done, besides the recommended injection tune up. But even if my TPS and injection circuit are perfects, the ECU mapping may need something 100+ degF and humidity compensation.

Every day we are most between 105 and 110 F....

The plug colour is almost totally dependent on the way you operate the engine. Lots of cold starts and short commuting trips and they will always be sooty with the std heat range. Flogged mercilessly and they will be clean. Plugs readings on a commuter bike is fraught with complications. Thats why race bikes did plug chops in the old days at the end of the practice session with a full throttle blast down the straight and race engines with 1000klms on them look clean as a whistle inside.

 

Phil    

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Posted

Speaking of plug reading.. here are the insulators on the Verner after about an hour's running. Cylinders # 1,2,and 3 from right to left respectively. To me, 1&2 are lean, 3 about right?

20230829_142347.jpg

Posted

Personally Chuck I would say the right hand plug in the image looks perfect. Clean ceramics, no speckly deposits, sharp defined edges on the clean electrode. The others look rich. Interesting plugs. You can remove the ceramics from the body then like old aero plugs?

Phil  

Posted

Thanks, Phil. I just put them in the lathe and used a parting tool to cut through the crimp.

Posted
20 hours ago, Chuck said:

Thanks, Phil. I just put them in the lathe and used a parting tool to cut through the crimp.

Keen :)

 

Phil

Posted
On 8/30/2023 at 10:37 PM, Chuck said:

Speaking of plug reading.. here are the insulators on the Verner after about an hour's running. Cylinders # 1,2,and 3 from right to left respectively. To me, 1&2 are lean, 3 about right?

20230829_142347.jpg

Which plugs are from the lower cylinders? I thought that those could have more oil fouling, but there doesn't seem to be any sign of that. Your oil scavenge system must be good.

I've never been able to reach firm conclusions looking at plugs. It seems that they look different depending on whether they were removed after a long taxi at idle, or a cut from power. If it was an idle fuel cutoff, then my opinion is the RH plug was running a bit lean.

Unleaded gas always makes the plugs look a bit darker than leaded avgas; what do you use?

Posted

2 and 3 are the lower cylinders. Unlike every radial I've dealt with it doesn't burn or leak oil. What's up with that? :D No idle cutoff, idled at 1000 rpm per the manufacturer's instructions during taxi back, and idled for a few seconds at 600 before shutdown. Unleaded auto fuel 90 (US) octane, no alcohol.

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