"California gas" ruined engine.

[ballisticexchris]

Ok, apparently everybody but me knows what CA gas is. The only gas I know about that can't be used in all engines is E-85. The only non-E 85 gas we have around here is 10% ethanol (max). And except for a 2mpg decrease, I haven't seen any other issues. So, what is CA gas? Enlighten my little pea brain.

California has a "special blend" for emissions. That is why they pay more for gas than the rest of the country. They are the only ones who use it.

Almost all gas sold in CA is E10. The E85 is 85% ethanol. Nothing special. That's a drag that a dealer wants to feed a customer with CA gas BS. And every single drop of gas produced in the world (of each octane) , coming out of the refinery, is the exact same blend. The only thing different are the additives for each particular brand.

And yes lugging the motor makes sense if there are carbon deposits. I sure do wish you the best getting this sorted out.

 

[HeliMark]

I just have to add, I have put at least 200K+ miles on motorcycles using "Ca gas", and have not had a problem. A good amount of miles on my Tenere was splitting heavy traffic in L.A., which usually is at low RPM's, and no problems. I would also find a different mechanic, and find out what is happening.

 

[Sierra1]

Low rpms, doesn't necessarily mean "lugging". Low rpms in too high of gear does though. So, with the exception of possible additive differences, CA gas is the same as everybody else's 10% ethanol.

 

[WJBertrand]

I’m beginning to wonder if this just started out as a classic hard start (they can be pretty stubborn sometimes) and the stupid mechanic performed a leak down test with the cams in the decompression position and everything went downhill from there.

Was a compression test also run? If that result was good, then the leak down numbers are suspect.

 

[Recurveit]

I was talking to a guy on a gs that had a S10 and he said his carbon up the valves at 15000 miles. He reccomend to me to put Med RX in the gas

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[Heathbar]

Strictly mechanical thought, I’ve seen this on Tenere’s before. I’ve helped several people with the same issue. I don’t recall any of the other folks being from California. The one common thread that connects the folks I have helped, (with carbon’ed up valves), has been ‘lugging’ this motor.
I’m in no way suggesting the original poster has, or has not done this. Only saying I have seen this same situation before on several Super Teneres.
If you lug this motor even with fuel additive, I believe it would probably happen again. I always suggest running the RPM’s up to 6-7K+ at least once a ride, if not more often ! (always be as safe as possible doing so)
I know of someone I’ve helped, I believe last year. I can touch base and see if he can add to this. He can give his own personal account (of the same issue) and what he now does to avoid it happening again, revving the bike up, and riding it with a bit more ‘spirit’. A lot MORE “spirit” !
What I have just posted probably does nothing for your current situation, but with my experience I can suggest how not to go down this road again.

Thanks for the info. I don't usually race it around but if I get the bike back, I certainly don't want this issue to happen again. I will get those RPM's up more. I have looked at other threads talking about compression ratios of engines and what octane fuel to use for best performance or fuel burning, etc. But honestly it's a little over my head.

 

[Heathbar]

I was talking to a guy on a gs that had a S10 and he said his carbon up the valves at 15000 miles. He reccomend to me to put Med RX in the gas

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Yes this is what Yamaha and the dealership is saying to do. I'm just mad it wasn't disclosed on the sale or from Yamaha themselves.

 

[Heathbar]

I’m beginning to wonder if this just started out as a classic hard start (they can be pretty stubborn sometimes) and the stupid mechanic performed a leak down test with the cams in the decompression position and everything went downhill from there.

Was a compression test also run? If that result was good, then the leak down numbers are suspect.

I don't know if a compression test was run first. I'll have to ask. I was told however, that they did the leak down test twice, just to make sure of their findings. I am not too impressed with the technician though. I think he should have tried to get the motorcycle started first (with ether or something) so he could run it on a scanner or tester or something to make sure everything was normal. The technician just tried starting it like I did (with the starter) and it would start for them, so they started breaking it down, looking at the valves, etc.

 

[Heathbar]

Bullshit. Plain and simple.

Ca gas is gas.

All my bikes have and do run just fine on Ca gas.

Bullshit.

Absolutely, now only if the dealership can find the issue that caused the valves to carbon up so much.

 

[Heathbar]

Side note: when I do a valve check for a customer I give them the before and after clearances of each valve for there records. Ask your dealer for that sheet, I gotta see this there sheet.
If you want an example I’ll send you one, PM me. If they can’t hand you over a (what I call a) “work sheet”, I would call BS on them even checking the valves.
Also I’ve obviously not seen the inside of your motor. But I have seen many Tenere motors and fixed many. If by what you describe is what I have helped others fix in the past, the job is not that hard to fix. You ‘shouldn’t’ need to replace valves or any other valve train. They can be cleaned and lapped back in the seats. Just FYI

Good, I'll ask then for this. Also, the service advisor seems to think he sees some type of "cupping" or "crescent" shape forming near the top edge of the valves. He is saying that the valves have a coating on them and if it wears away it makes valves more susceptible to damage? I'll have to ask if he thinks the carbon formed and is denting or "cupping" the valves toward the top?

 

[Heathbar]

if you have the heads and they Haven't been disassembled run some fluid through the intake ports and you'll see where the leakage is...if any, it'll weep through the valves..

Thank you.

 

[Heathbar]

Almost all gas sold in CA is E10. The E85 is 85% ethanol. Nothing special. That's a drag that a dealer wants to feed a customer with CA gas BS. And every single drop of gas produced in the world (of each octane) , coming out of the refinery, is the exact same blend. The only thing different are the additives for each particular brand.

And yes lugging the motor makes sense if there are carbon deposits. I sure do wish you the best getting this sorted out.

Thanks for your response. The station where I buy gas is 10% ethanol and I always use 91 octane. Maybe I need to keep the RPM's up. I cruise the freeway at about 80 in 6th gear and I havent had the bike for two months because it is at the dealership, but I remember an RPM of about 4,000 at that speed I think. Maybe keep it in 5th gear for a while? I'm assuming when the RPM's are higher it makes the engine run hotter and the engine will burn more of the fuel without leaving it unburned and turning it into carbon deposits?

 

[Heathbar]

I just have to add, I have put at least 200K+ miles on motorcycles using "Ca gas", and have not had a problem. A good amount of miles on my Tenere was splitting heavy traffic in L.A., which usually is at low RPM's, and no problems. I would also find a different mechanic, and find out what is happening.

I have had 7 or 8 bikes in my life (from a 76 Honda 550 Super Sport, to a Kawasaki Vulcan, to a Yamaha V Star, an others in between) and also haven't experienced anything like this. Very frustrating.

 

[Jlq1969]

So, if there are many S10 (as Tabasco says) that have decompression problems, caused by carbon deposits in the valves, should I remove the label of "reliable" from my S10 "?????
And another thing that I do not understand is that if in all countries, they try to reduce the carbon footprint (by adding alcohols in the fuel which coincides with the California blend), how could it be that more carbon deposits are formed now that before?, that means that alcohol apart from moisture, more carbon forms its combustion ?. I do not mean about direct injection (where there is no cleaning of the intake valve) orDiesel in this, where the addition of oils that have not been well filtered from fats and paraffins, "can" produce lacquers if the combustion is not complete, but alcohol????

 

[Jlq1969]

Thanks for your response. The station where I buy gas is 10% ethanol and I always use 91 octane. Maybe I need to keep the RPM's up. I cruise the freeway at about 80 in 6th gear and I havent had the bike for two months because it is at the dealership, but I remember an RPM of about 4,000 at that speed I think. Maybe keep it in 5th gear for a while? I'm assuming when the RPM's are higher it makes the engine run hotter and the engine will burn more of the fuel without leaving it unburned and turning it into carbon deposits?

It is assumed that the injection and the lambdas, are responsible for correcting the amount of fuel, even if you go at low rpm
Perhaps the carbon problem is another. Excessive oil level?...Defective valve seals, mechanical obstruction of exhaust gases, excessive oil consumption?

 

[WJBertrand]

I don't know if a compression test was run first. I'll have to ask. I was told however, that they did the leak down test twice, just to make sure of their findings. I am not too impressed with the technician though. I think he should have tried to get the motorcycle started first (with ether or something) so he could run it on a scanner or tester or something to make sure everything was normal. The technician just tried starting it like I did (with the starter) and it would start for them, so they started breaking it down, looking at the valves, etc.

I’m betting there wasn’t anything mechanically wrong in the first place. I agree the “technician” should have tried more ways to start it before suspecting major mechanical failure, especially assuming the bike was running just fine the last time you rode it? If they did the leak test wrong twice, that means nothing.


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[Eville Rich]

And another thing that I do not understand is that if in all countries, they try to reduce the carbon footprint (by adding alcohols in the fuel which coincides with the California blend), how could it be that more carbon deposits are formed now that before?, that means that alcohol apart from moisture, more carbon forms its combustion ?.

Just a FYI, the ethanol is E10 is there for two primary reasons. The first is to improve emissions, primarily NOx which is a precursor to ground level ozone. It also acts as a boost to the octane rating. The second reason is to diversify the energy supply and subsidize farming. There can be some marginal net GHG benefit but it's not the main reason for E10. E85 requires a completely different engine tune or you would end up running lean. You can also get very high octane numbers with E85. I think it's popular for racing or true flex fuel vehicles.

The ethanol wouldn't add to carbon deposits - it would probably reduce them, all else held equal. There's also not a connection between engine carbon deposits and carbon emission from the tailpipe. Both gasoline and alcohol provide their combustion energy by the breaking of bonded carbon molecules. With pure combustion you end up with CO2 and water. When the engine is lugged you can end up with incomplete combustion, leaving unburnt hydrocarbons behind. As others have mention, running at high RPMs and getting things nice and hot can help prevent that.

Eville Rich
2016 S10

 

[advmgm1]

What brand of gasoline do you run in the S10?
All of the top tier fuels, particularly the premium grade, have techroline in them that keeps the valves clean.

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[Jlq1969]

Just a FYI, the ethanol is E10 is there for two primary reasons. The first is to improve emissions, primarily NOx which is a precursor to ground level ozone. It also acts as a boost to the octane rating. The second reason is to diversify the energy supply and subsidize farming. There can be some marginal net GHG benefit but it's not the main reason for E10. E85 requires a completely different engine tune or you would end up running lean. You can also get very high octane numbers with E85. I think it's popular for racing or true flex fuel vehicles.

The ethanol wouldn't add to carbon deposits - it would probably reduce them, all else held equal. There's also not a connection between engine carbon deposits and carbon emission from the tailpipe. Both gasoline and alcohol provide their combustion energy by the breaking of bonded carbon molecules. With pure combustion you end up with CO2 and water. When the engine is lugged you can end up with incomplete combustion, leaving unburnt hydrocarbons behind. As others have mention, running at high RPMs and getting things nice and hot can help prevent that.

Eville Rich
2016 S10

I agree, that is why I believe that if there are carbon deposits, in an indirect injection, it is more related to oil than fuel. Small threads of oil seep through the valves (in the exhaust they are burned, but in the inlet it is the same fuel that washes the valve (except in direct injection). And this refers me to the excess oil that generates excesses of oily vapors in the inlet (which should be seen in the filter box), or excessive wear of the piston rings causing oil to enter the combustion. I do not agree that the culprit of the carbon is the fuel just by adding alcohol . In vehicles that only run on alcohol, such as those that run on compressed gas, the oil when it is changed comes out practically clean(no carbon) Perhaps, all of us have carbon deposits in the piston or in the valves (surely we do) ... but having to circulate with the engine at 70% of its maximum revolutions, so that these deposits do not form, I do not think it is the intention of the factory, and if it were, manufactures would not make a motorcycle with a box of 6 gears for the engine run relaxed, it would do it with a 4-speed box so that it always runs at high rpm and avoids having to repair the engines with 16,000 miles within the warranty. If we add one more item, causing the engine to run cooler than the recommended temperature may cause the piston ring seal to be incorrect and allow oil to leak through the combustion (probably carbon deposits)

 

[cyclemike4]

I sure hope you have good news on the bike and it gets resolved what ever caused the problem. Good luck to you.