***KNOCK ON THE DOOR*** Carbon tear down

[~TABASCO~]

Helping someone: Ive been helping out an owner, I want to share a few photos so he can see what is going on. I believe that he is having an issue with carbon build up on the valves. Here are a few photos of the inside and what has to be done to fix leaking carbon build up on the valves.
1) pull the top end down
2) pull the head
3) pull all the valve keepers & retainers
4) pull all the valves
5) clean all the valves and the valve seats
6) wipe and make sure everything is clean
7) lap each valve put back in the same location
8) reinstall everything, using new head bolts and head gasket
9) torque everything 100% properly and double check all your work, dont forget to add the +30*
10) should work as good as new (literarily)

For folks that stumble across this post, dont forget to rev your bike up each ride as you're getting on the highway, Etc. Run it a bit hard, rev it up, DON'T short shift all the time. Try and run a fuel product like "Sea-Foam" or something similar often in this motor. This motor is absolutely fantastic, but it does have a tendency to carbon up a bit. If this goes on it will begin to leak. It also affects the valve clearance. (and other issues) Once there is enough carbon on the valves it basically loses compression, and the bike runs poorly or eventually wont even start. This is the cause, here is the quick answer to fix it. With a few photos.

 

[Fennellg]

Tobasco, do you know what oil and weight he ran? Was having a carbon build up problem with my sonata. I rans some carbon build up cleaner via a vacuum hose. Wella problem fixed. Had to clear the code and limp mode.

I read on Hyundai forums that our beloved T6 oil was recommended for prevention of carbon Build up. Did not want 5w 40 oil. The viscosity scared me. My year was also blessed with the metal shaving problem so I changed often and thin 0w 20 Mobil one. Apparently 0 weight makes carbon build up worse. Went back to 5w 20 Mobil one and put a catch can on. Car seems happy. The dealership is always impressed how smooth and quiet it runs.

I defer to your judgement, with that said have seen a lot of before and after pics and videos. That engine does not look that bad to me. Less invasive measures may have gotten desirable results. It did in my case.

 

[~TABASCO~]

Tobasco, do you know what oil and weight he ran? Was having a carbon build up problem with my sonata. I rans some carbon build up cleaner via a vacuum hose. Wella problem fixed. Had to clear the code and limp mode.

I read on Hyundai forums that our beloved T6 oil was recommended for prevention of carbon Build up. Did not want 5w 40 oil. The viscosity scared me. My year was also blessed with the metal shaving problem so I changed often and thin 0w 20 Mobil one. Apparently 0 weight makes carbon build up worse. Went back to 5w 20 Mobil one and put a catch can on. Car seems happy. The dealership is always impressed how smooth and quiet it runs.

I defer to your judgement, with that said have seen a lot of before and after pics and videos. That engine does not look that bad to me. Less invasive measures may have gotten desirable results. It did in my case.

He said Motul.

The engine in these photos would no longer run and had about 20-30 psi test. After cleaning it ran perfectly.

 

[Sierra1]

. . . . dont forget to rev your bike up each ride as you're getting on the highway, Etc. Run it a bit hard . . . .

"But officer, Jaxon told me I had to ride like this". Bahahaaaa!!!! View attachment 98273 I'm betting my motor is very clean. Even my Jeep motor is gonna be clean. It's a manual and loves to rev. (totally opposite to my 4.0L)

 

[Fennellg]

Was it the pistons causing the trouble? Sonatas it's the valves.

 

[Fennellg]

So moral of the story. Rag the bitch. Ride it like you stole it. For those who get your oil tested and abide by a longer interval be aware there are other considerations. Oil, octane, and intervals directly affect carbon build up. I have been know to ragg my car. Would see a black carbon cloud from time to time. But when I went 0w 20 the battle started to turn against me.

 

[Fennellg]

A little knowledge can be a dangerous thing.

 

[Fennellg]

Don’t want to start another oil war thread the oil is respected weight and interval would be useful to to forum should you come across the info.

We love you but we love our bikes more

 

[Wheelin]

Tobasco, do you know what oil and weight he ran? Was having a carbon build up problem with my sonata. I rans some carbon build up cleaner via a vacuum hose. Wella problem fixed. Had to clear the code and limp mode.

I read on Hyundai forums that our beloved T6 oil was recommended for prevention of carbon Build up. Did not want 5w 40 oil. The viscosity scared me. My year was also blessed with the metal shaving problem so I changed often and thin 0w 20 Mobil one. Apparently 0 weight makes carbon build up worse. Went back to 5w 20 Mobil one and put a catch can on. Car seems happy. The dealership is always impressed how smooth and quiet it runs.

I defer to your judgement, with that said have seen a lot of before and after pics and videos. That engine does not look that bad to me. Less invasive measures may have gotten desirable results. It did in my case.

First of all, thank you to Tabasco for all your help and wisdom.

The oil that I was running was Motul 10W-40 full synthetic. I typically change it every 5,000 miles. I love this bike, and I commute 100 miles round trip Monday through Friday at 80-90 mph. So I’m surprised that things should get so gummed up.

 

[Fennellg]

Thank you. And ditto on Tabaco

 

[Fennellg]

Well what octane do run. Any gas station loyalty. I have been suspicious that a gas station here and there has bumped me down a grade for sale in gas and charge for the higher grade. Pay for 93 or 92 and get 89 or 87.

 

[Cycledude]

That’s the reason I frequently use Marvel Mystery Oil in the gas.

 

[Wheelin]

Well what octane do run. Any gas station loyalty. I have been suspicious that a gas station here and there has bumped me down a grade for sale in gas and charge for the higher grade. Pay for 93 or 92 and get 89 or 87.

I was consistently running 91 octane (the highest available in my locality), and I would usually go to a 76 or a Chevron station. Pretty hard to avoid a small amount of ethanol here and there. And some people that I’ve corresponded with actually believe that the higher octane may also contribute to carbon build up. I’m not a chemical engineer, nor am I a mechanic. I tried my best to go by the book on periodic maintenance. It’s frustrating, and I imagine I’ll be reading “you should’ve done this or that” somewhere in the thread. That’s fine. I know that from now on, I’ll regularly be putting seafoam in my fuel to keep the carbon gremlins away!

 

[Fennellg]

Not faulting you. Just trying to understand. I believe we both have the same goal. You don't want a repeat and others myself included would like to avoid it all together.

Given that you were commuteing the ethanol would not be a problem. Again I would defer to Tobasco. As for octane higher the better. From my research, but Again I defer.

 

[sheikyerbooty]

Higher RON=higher ignition temps=less deposits?

or is it not that simple?

 

[Jlq1969]

If we rule out the quality of the fuel, if we rule out the quality of the oil, that the amount of oil was always correct and its corresponding changes in time, if we rule out valve adjustment... and "assuming" that the use of the engine is normal a human being (not necessarily at the top of the revolutions), and also assuming that the Yamaha engine engineers design it with the idea that it "contaminates little" (what carbon deposits would mean an excess of "something" bad burned), and taking as a reference that the 11:1 compression, although it is little compared to the bike competition, is not so little compared to the vast majority of vehicles that circulate on the streets… ..as a personal opinion, I would think that the culprit of the deposits, is a bad sweep of the exhaust gases
And "probably" the cause of the bad exhaust sweep is the catalytic converter (or the muffler). "At full engine load", the catalytic converter ( or the muffler), probably allows good exhaust gas scavenging, but at low revs, it probably interferes with proper exhaust gas scavenging... It's a personal opinion, but today, with the technology that it exists in lubricants, fuels and especially in fuel injection….the formation of carbon deposits would be almost impossible. This problem usually occurs in gasoline and diesel vehicles, whose main use is in the city and have the EGR system (exhaust gas recirculation)

 

[Fennellg]

A decat could help? And give better power. Opinions, recommendations, and speculations please. A useful direction is being charted.

 

[Eville Rich]

I've got carbon build up on my valves and plan to follow the recommendation of using Seafoam on a regular basis plus running the engine a bit harder. I'm definitely someone who hasn't pushed the engine hard enough on my regular riding.

What I'm wondering about is the ability to reduce/remove the existing carbon without pulling the head or resorting to walnut shell blasting. I'm doubtful that Seafoam will remove existing carbon deposits, but I suppose it's possible. Will harder running do that (aka Italian tuneup)? What about other products like the CRC GDI spray, touted as doing this sort of thing for direct-inject engines? I'm wary of snake oil and feel-good chemical treatments.

Regarding octane - higher octane burns at a slower pace than lower octane. I don't think higher octane will help, though it probably doesn't hurt, if you are working the engine, loaded at higher rpm.

Eville Rich
2016 S10

 

[Sierra1]

I think the length of trips could also influence the carbon. I know it's apple & bananas, but I had an old Chevy truck with a 305ci and 4bbl carb. It would develop a hesitation when driven around town for a while. Until it was driven on the highway for extended periods. Hesitation disappeared and actually seemed to have more power. I wouldn't think that this would apply to Wheelin considering his 100mi per day trips though.

 

[Fennellg]

You can run this. It worked for my Sonata. Wanted to do a 2nd treatment but pandemic shortages prevented. I subbed carb and choke cleaner. Worked well also and is more readily available.

Add a little Mystery oil to your gas (or the elixir of your Choice to the gas once in a while).

A coupe of 100 miles before my Sonatas oil change I would add some mystery oil to the oil. Every thing helped some but the CRC did the trick.