TE/TC Could use an opinion on this cylinder scarring...

This is a bore scope shot of my '17 TX300. I'm thinking I may need to pull the head and see how bad the scarring is, but would like to get some opinions before I go through the process:

Thanks.
Cosmo.

I have marks in my 2.4hr cylinder. I was surprised when I took the head off and may need to look further. Mine are at the ring end gap. Cam.

sorta looks like cross-hatching?

Not talking about the normal cross hatch. It is the vertical band that goes between the two ports that you can see at the top of the photo. The port, that's hard to see to the left of the wider band is the main exhaust port. The one on the right is obviously the side port. The above photo is magnified a bit. The wider band is only a few millimeters wide.

I pulled the head this morning, and I can ever so slightly detect the edge of the wider one via a fingernail. I was going to take a better photo with my cell phone but, in fact, it's such a slight amount of rubbing that I have to get the light positioned just right in order to see them.

I think I'm going to run it until the end of our riding season, which should be coming up pretty soon. I.e. my main riding area here is going to close Jan. 1.

I have almost the same marks. One each side of the exhaust port. It is where the ring endgap is I think. Mine have no texture, just a difference. I may take the cylinder off and check the ring end gap to make sure it is spec. I don't recall ever seeing that before on a new unit, only on old old bikes. Cam.

hell, I thought those were photo side-effects.

well, if you can feel them it means they're greater than 0.0002" maybe? before you pull the head, do a compression test. (oops. reread it- you've already pulled the head). (edit: just looked it up- some researchers are claiming that human fingers can distinguish rough surfaces down to 13nanometers. I'm not calling them liars... but NFW)

good luck.

Does the engine have any issues? Hot seize? low compression? How many hours? What fuel to oil ratio are you running?

Take the bike to your dealer if it's still in warranty. The Nikasil coating should not have worn through so soon. It could be the piston depositing aluminium on the cylinder wall instead of cutting a groove in the cylinder. Either way, it looks like it needs a new piston and cylinder plating check.

I wouldn't know a hot seize if it happened.
Compression is 155 psi (@ 1,200 feet elevation).
60 hours.
Last ride I used AvGas at 40:1, but I was running CA 91 Pump gas at 60:1 (per the manual) up until the last ride.
The USA warranty is only 30 days on this bike, so that's a no go.

I'm going to run it for the remainder of the month and pull the whole thing apart and just have it re-nikasil and a whole new top end. I'll probably put VForce reeds and a S3 head in while I'm at it.

at this point, I might put a new set of rings on... but maybe not.

Enjoy it. Ride it. A year from now, do a complete top end including Nikasil (which is like $3-400 alone IIRC).

if it's not a bad ring, it looks like something semi-soft (brass, aluminum) went through your engine. the damage isn't eye-opening.

I t doesn't look too bad to me but another reason to ditch the Lectron now IMO . Or at least richen it up . What does the the top of the piston look like ?
What oil you running ?

or quit doing 60:1

I suppose. But it doesn't really look like a heat or lubrication problem to me. Anybody else?

admittedly, I do like my fuel/oil ratios to be a little oil-richer. Although nowadays 60:1 is not uncommon.

I was thinking it was a lean fuel to air ratio causing heat

I had similar marks on my 165 and was possibly linked to detonation

(I wouldn't run 60 to 1 )

Interested to see spark plug

With your other issue of having not much of a hit - Ive noticed and also heard from experts that these bikes like fuel for down low power.

You would have to think theres a slight ring anomoly, just strange its such a distinct event in that vertical part of your cylinder. Could be a minor seizure.

Motorex cross power 2T. My owner's manual says 60:1 for 91 unleaded. But at 95 unleaded it says to use 40:1. So with the avgas I've started using, I've switched to 40:1.

Here's the piston (note I'm not completely sure, but that the scratch in the very center of the piston in the carbon is, I think from my bore scope making contact. But if it's not from the bore scope, that could explain a few things. But what could it be -- the reeds are in perfect shape?)...


Here's the cylinder, note that I cleaned the piston top before taking this pic (this shows the width of the scar in relation to the rest of the cylinder better than the pic in the first post)...


And the plug (what are all those gobs of stuff around the electrode?)...

well, you're rich enough in A/F and oil. Actually, the plug says too rich (you can clean 'em with a propane torch- get the center white insulator red-hot for about 30 seconds. re-gap. done). You're not sucking in tranny oil, are you?

The "gobs" on the plug are carbonized oil- same as the crown. Not aluminum vapor if that's what you're thinking.

note the gouges in the top of the cylinder right where the big striation starts. I'm still thinking something went through your top end.

the crown scratches are fresh and nothing to worry about- as you suspect.

ride it- you're good. whatever happened is done.

I've had the plug out so many times to check the A/F mix due to the carb issues I've had, that I wouldn't be surprised if some mud fell in the hole.

Me, I would pull that jug. Polish the power valve, hone with nikasel brush, stick new piston and ring in.
To me???? Hard to say from pics but looks like you might of popped a wrist pin clip. Then the wrist pin is out rubbing up and down the cylinder. Sure looks like the mark it would make, cause I had one do that. Except it dug deeper. I could not tell either till I pulled jug to ring it. Maybe not but you won't sleep until you look at cylinder, piston and rings.

Shit! I forgot about that. That happened on my KLR 650. That might explain the partially round mark on the top of the piston, too.
EDIT, oh wait, it wouldn't make it to the top of the piston, I'd probably find it in the case.

I'll disagree with that it couldn't make it to the top of the piston . I've worked on a couple of other left kickers that start with M that the big end rod bearing was coming apart and collapsed the ring groove causing the ring to stick . I'm not saying this is your problem but I've seen it more than once . If you have ANY concerns as to what is happening pull the cylinder and check it out , as far as you already have it apart , why not . Buy the addition gaskets that you need to put it back together .