[Tom750monster]

Hello,

I've noticed from taking off both spark plugs that the spark plug from the horizontal cylinder is a white ish colour and the spark plug from the vertical cylinder is black.
I suppose these should both be a nice red brown colour right?
I've also noticed that the horizontal cylinder makes a knocking sound, it doesn't sound really bad but doesn't sound that nice either.
It's like a lean knock sound or pinging sound I guess but I'm not sure if that the best way to describe it.
When I take both spark plugs out and turn the engine over with the electric start it doesn't make that knocking sound anymore.
Could it be because I'm using SP95 and should be using SP98 petrol?

Any suggestions are appreciated!

 

[johnnycay57]

It might be just me, but I think that the one from your vertical cylinder looks like It's oil fouled a little bit. Possibly valve seals.

 

[Guido C.]

Hello,

I've noticed from taking off both spark plugs that the spark plug from the horizontal cylinder is a white ish colour and the spark plug from the vertical cylinder is black.
I suppose these should both be a nice red brown colour right?
I've also noticed that the horizontal cylinder makes a knocking sound, it doesn't sound really bad but doesn't sound that nice either.
It's like a lean knock sound or pinging sound I guess but I'm not sure if that the best way to describe it.
When I take both spark plugs out and turn the engine over with the electric start it doesn't make that knocking sound anymore.
Could it be because I'm using SP95 and should be using SP98 petrol?

Any suggestions are appreciated! View attachment 230338

View attachment 230337

I agree. My first guess was oil fouled. The other plug is fine. With modern fuel injection the nice brown color we used to look for doesn't exist anymore. Modern bikes run leaner for cleaner air. I would switch to hi- test gas and I'd do a leak down test on the questionable cylinder to eliminate more serious problems first before you tackle valve seals.

 

[cs363]

Good advice in the posts above, especially the above re: leak down test after running on a higher octane for a bit.. For my money I'd also change out those plugs to NGK of the correct heat range, they are way more reliable and yes, run the bike on the highest octane you have readily available, your bike will thank you for it.
Probably worth checking the air filter is clean (along with the airbox) and if it's an aftermarket oiled type filter make sure it's not over oiled.
Do you know the service history of the bike, and has it had the valve clearances checked on schedule?
Seems to be a lot of oil on the threads of those plugs or is that just grease from installation?

 

[ronski]

All of the above advice, but mainly, put in new plugs, the black one is not firing correctly.
The sound you hear could be that plug miss firing, sounds like coughing or backfiring slightly, even similar to pinging or clicking.
Grade of fuel is your choice, but it would affect both cylinders, not one.

 

[Tom750monster]

Thanks for the response guys. What I'm going to do is get the most premium petrol available, change the spark plugs to NGK DCPR8E, change the air filter, change the oil and oil filter and see if that affects anything. The leak down test sounds like a good idea but my air compressor's drain plug threads are stripped so can't use it at the moment. 😭
For the service history I've got the paperwork so I will have to check it again.

 

[Tom750monster]

Update : so now I've done an oil change + oil filter, it was pretty dark oil but luckily very few flakes of metal on the oil strainer.

I then refilled it with Shell Advance ultra 10w40 100% synthetic.
It's now running on high grade SP98 petrol.
I also mixed it with Redline Sl1 complete fuel system cleaner.
• Changed the spark plugs to NGK DCPR8E
• New air filter

The front area of the engine still makes a tapping/ticking noise...
Makes me think it might need it's valve clearances adjusting but not sure.
These videos were taken before this service was done but it pretty much sounds the same.

 

[johnnycay57]

I'm going to weigh in ...there will be others. That "two-stroke ping" sound coupled with the appearance of your spark plugs I think means you have excessive carbon build-up in at least one cylinder. Could be caused by oil leaking into the cylinder and other problems. The carbon build up can cause preignition (which is what I think you we hear in your video). I'd pull the head and have a look. IMHO, if you run it, it's gonna let go. De-carboning the head surface and piston surface, solve for oil leak problems (I'd replace the valve stem seals at minimum). I wanted to wait for Ducatistas to comment but I felt this too important to just let go. Thanks for your post.

 

[ronski]

Makes me think it might need it's valve clearances adjusting but not sure.

At least check the clearances before diving into the head.

Run it for a bit, then check plugs again. I've listened to the video a few times, can't hear anything that would worry me, but then I'm getting old and probably half deaf.

 

[cs363]

+1 To what @ronski says above.
Mind you, I'm suffering from the same complaints.... 👴

 

[Tom750monster]

Regardless of if I fix this noise issue or not I will be checking those valve clearances anyway as I don't know when they were last done.

"I think means you have excessive carbon build-up"

Regarding what you said about carbon buildup here are some pictures I took with my borescope of the insides of both cylinders.
(pictures taken before service) I also think it had a tad too much oil in it before so that couldn't have helped.

Ducati monster borescope pictures

I can't remember which photos correspond to which cylinder but they look both quite similar.

 

[cs363]

Can you get Seafoam or a similar product where you are? Might pay to run something like that through the system, it'll help clean up some of that carbon and excess oil as well as cleaning the fuel system.

 

[Tom750monster]

Well I've already put Redline Sl1 in the fuel. The problem is I can't take it out on the road as it's not yet registered or insured.
Would it clean the cylinders just from revving the engine?

 

[cs363]

It might, though for that scenario you're better off using one of those sprays that you spray through the inlet whilst the engine is running, Seafoam, CRC & Nulon amongst others make them, I'm sure there's something similar in your area. Just be warned that you need to do it in a well ventilated area as it normally produces a lot of smoke...
This is the SeaFoam product: Sea Foam Spray | Intake Valve and Top Engine Cleaner and Lubricant
Personally, I think I'd wait until you have it ready for the road and then take it for a good ride with plenty of hard acceleration and deceleration. I think a few miles on it should clean it up, though you may end up having to chuck another set of plugs in it if they get fouled up.