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Just lean harder...
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Discussion Starter · #1 ·
Here are a couple of pictures of how much of a difference running a good synthetic oil like Mobile1 4T or Amsoil can make.

These pictures are of the intake valves looking down the throttle bodies.

First bike is a 2008 GSXR 1K w/ 15k miles that is female owned since new and has always been serviced at a Suzuki dealer every 3k miles with organic oil. I have now convinced her to switch.



Second bike is a 2007 R6s w/ 57k miles that was being serviced with Yamalube until 18k miles when I noticed carbon buildup on the valves (wish i had a pic). I then switched to Amsoil for a couple of services but now run Mobile1 4T because its stocked at most parts stores.

 

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Pastor of Muppets
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Impressive but, how can you be sure that the oil is the only reasoning behind that?

How about air filter, fuel, riding and storage conditions?
 

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UR B-hind Da 8 Ball
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So, explain to me how a part that never touches oil is so affected by what oil is used....

I would say that there is something else involved. Like, loading the engine at too low of an rpm, or the fuel being used.
 

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pin it to win it
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Ye oil doesn't get there. That cabin build up would be from a/f ratio and how you ride
 

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It's oil from the crank case vent tube thats routed to the air box. The oil mist cools off on the back side of the intake valve an leaves carbon deposit. Better oil, less carbon deposit.
 

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Just lean harder...
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Discussion Starter · #7 ·
It's oil from the crank case vent tube thats routed to the air box. The oil mist cools off on the back side of the intake valve an leaves carbon deposit. Better oil, less carbon deposit.
Yes, that's why race bikes will use an oil catch can and residual oil residue also seeps past the valve seals.

Motors that have direct port fuel injection, where the fuel is sprayed directly into the cylinder suffer from worse carbon build up because the fuel does not spay onto the valves that helps clean them.
 

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You really don't want that crud building up on the back of your valves as that changes the profile of the back side of the valve which effects air flow, so less power over time.

Quality Oil and Gas is your best defense, plus unplugging the crank vent hose from the air box. You can vent it to a small K&N filter designed for that purpose or even do the sucker mod with it, or just into a catch tank.
 

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Reads the rulez
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Bob just got the biggest boner of his life because of this thread.
 

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"The Dude abides .. "
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Now correct me if I'm wrong, but I'm almost positive no oil sees that part of the valves intake or exhaust. Otherwise the bike would smoke like a 2 stroke or an older bike with leaky valve seals.


So, explain to me how a part that never touches oil is so affected by what oil is used....

I would say that there is something else involved. Like, loading the engine at too low of an rpm, or the fuel being used.
:werd ..
agreed. oil has ZE-RO to do with what the tops of intake valves look like. Unless.. the valve guides are toast and you are consuming copious amounts of oil, but you would look like the mosquito control truck fogging the track..
 

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"The Dude abides .. "
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It's oil from the crank case vent tube thats routed to the air box. The oil mist cools off on the back side of the intake valve an leaves carbon deposit. Better oil, less carbon deposit.
but come on .. that is simply crankcase ventilation, you are NOT getting OIL going through there. Even "mist" of one form or another.. has zero to do with the photos that guy posted. Nothing at all.
The breather hose is on the very TOP of the motor. There is no oil passing through there. You could have darn near sludge flowing through a motor, you shouldn't get any buildup on the intake valves from that..
 

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"The Dude abides .. "
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there is no way in h-e-l-l you could convince me that the valves of that gsxr1000 "bike 1" got that way in 15,000 miles due to the type of oil used. that is a massively rich map, funky fuel injectors that are not spraying properly, shit pump gas, the rider (that just happens to be female) isn't ever opening the throttle, or a combination of ALL of these things... but crankcase oil being the cause (assuming the engine is in good condition otherwise) ? sorry mate. That is kinda laughable..
 

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Just lean harder...
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Discussion Starter · #14 ·
but come on .. that is simply crankcase ventilation, you are NOT getting OIL going through there. Even "mist" of one form or another.. has zero to do with the photos that guy posted. Nothing at all.
The breather hose is on the very TOP of the motor. There is no oil passing through there. You could have darn near sludge flowing through a motor, you shouldn't get any buildup on the intake valves from that..
Here, let me break it down for you.

What Causes Intake Valve Deposits

Intake valve deposits form as a result of oil slowly seeping past the intake valve guide seals and down the valve guides. A tiny amount of oil is necessary to lubricate the guides, but when oil reaches the hot surface of the valve, it can stick and burn forming heavy black carbon deposits that gradually build up over time. The higher the mileage on the engine and the greater the wear in the valve guides and seals, the faster the accumulation of black carbon deposits on the intake valves. Low viscosity motor oils (such as 5W-20 and 0W-20) may make the problem worse because they are thinner (to reduce friction) and flow more easily down the valve guides. Conventional motor oils also have a lower flash point than synthetic oils, which can also increase the formation of deposits over time.

Another contributing factor to the formation of intake valve deposits is unburned fuel vapors and oil vapors being siphoned back into the intake manifold through the Positive Crankcase Ventilation (PCV) system. This is done to control crankcase pressure and to remove moisture from the oil (which helps prolong oil life). The fuel vapors, carbon particles and oil droplets that the PCV system routes back into the intake manifold are reburned in the engine to reduce pollution. But these same vapors can also form carbon and varnish deposits on the intake valves.

The more blowby an engine has due to cylinder and piston ring wear, the greater the volume of crankcase vapors that are pulled back into the engine by the PCV system. High mileage engines typically have more blowby than low mileage engines, so the build up of intake valve deposits is grater.

:dunce: Yeah, I have no idea what I'm talking about......
 

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Reads the rulez
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Here, let me break it down for you.

What Causes Intake Valve Deposits

Intake valve deposits form as a result of oil slowly seeping past the intake valve guide seals and down the valve guides. A tiny amount of oil is necessary to lubricate the guides, but when oil reaches the hot surface of the valve, it can stick and burn forming heavy black carbon deposits that gradually build up over time. The higher the mileage on the engine and the greater the wear in the valve guides and seals, the faster the accumulation of black carbon deposits on the intake valves. Low viscosity motor oils (such as 5W-20 and 0W-20) may make the problem worse because they are thinner (to reduce friction) and flow more easily down the valve guides. Conventional motor oils also have a lower flash point than synthetic oils, which can also increase the formation of deposits over time.

Another contributing factor to the formation of intake valve deposits is unburned fuel vapors and oil vapors being siphoned back into the intake manifold through the Positive Crankcase Ventilation (PCV) system. This is done to control crankcase pressure and to remove moisture from the oil (which helps prolong oil life). The fuel vapors, carbon particles and oil droplets that the PCV system routes back into the intake manifold are reburned in the engine to reduce pollution. But these same vapors can also form carbon and varnish deposits on the intake valves.

The more blowby an engine has due to cylinder and piston ring wear, the greater the volume of crankcase vapors that are pulled back into the engine by the PCV system. High mileage engines typically have more blowby than low mileage engines, so the build up of intake valve deposits is grater.

:dunce: Yeah, I have no idea what I'm talking about......

No.
 

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Official Noob Greeter
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I am with Melk Man on this one. Oil in a motor otherwise in good condition is not causing this in 15k miles unless you have some extenuating circumstances. And I am not sure that you are going to aerosolize enough oil mist that it is in sufficient concentration to make it out the top of the head, through the reds in the AIS, and down the pipe back to the airbox, where it is diluted significantly further and mixed with fuel which can do a number on getting oil off of things, especially today's higher end pump fuels that have detergents and such in them.

Now I would say it is more likely that being its a 2008 with 15k (approximately 2100 miles/year) that it is likely a rich map, with a dirty air filter, on a bike that doesnt see a lot of significant rpm/high speed, extended periods of storage without proper fuel preparation, etc. Far more likely IMO than oil. FWIW, my 2001 was disassembled to replace the transmission at 24k miles using exclusively yamalube dinosaur oil and the valves were impeccable. The entire motor was clean. That was using a 2k mile oil change interval and quality fuels.

My drag bike, on the other hand, after 8 k miles and lots of sitting and using race gas exclusively (U4.4 which I am sure these guys will tell you turns into blue glue after a while) and its valves were pretty nasty, and that was only using either Motul 300v, Repsol Race, or Mobil 1 syn.

Oil is not the issue.
 

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"The Dude abides .. "
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Here, let me break it down for you.

What Causes Intake Valve Deposits

Intake valve deposits form as a result of oil slowly seeping past the intake valve guide seals and down the valve guides. A tiny amount of oil is necessary to lubricate the guides, but when oil reaches the hot surface of the valve, it can stick and burn forming heavy black carbon deposits that gradually build up over time. The higher the mileage on the engine and the greater the wear in the valve guides and seals, the faster the accumulation of black carbon deposits on the intake valves. Low viscosity motor oils (such as 5W-20 and 0W-20) may make the problem worse because they are thinner (to reduce friction) and flow more easily down the valve guides. Conventional motor oils also have a lower flash point than synthetic oils, which can also increase the formation of deposits over time.

Another contributing factor to the formation of intake valve deposits is unburned fuel vapors and oil vapors being siphoned back into the intake manifold through the Positive Crankcase Ventilation (PCV) system. This is done to control crankcase pressure and to remove moisture from the oil (which helps prolong oil life). The fuel vapors, carbon particles and oil droplets that the PCV system routes back into the intake manifold are reburned in the engine to reduce pollution. But these same vapors can also form carbon and varnish deposits on the intake valves.

The more blowby an engine has due to cylinder and piston ring wear, the greater the volume of crankcase vapors that are pulled back into the engine by the PCV system. High mileage engines typically have more blowby than low mileage engines, so the build up of intake valve deposits is grater.

:dunce: Yeah, I have no idea what I'm talking about......
could be wrong about this too, but looks like a "google" search for your explanation/description of valve deposits ;) Not that is incorrect, just not sure it's applicable to your case of a 15,000 mile (low miles) motor ..

I have had deposits on the intake valves of high hour crf450r dirt bike engines. This motor had hundreds of hours on it. BUT.. i use a high quality synthetic on my motors, and i wasn't sure it wasn't from the accelerator pump being adjusted a bit rich. it squirts a jet of fuel directly through the carb when you first open the throttle from closed. (fail #1 of your argument in my opinion).
And, the fact that the gsxr1000 engine has, as you stated, 15,000 miles.. and a female rider.. i am supposed believe the valve guides are so worn as to cause this problem, and you initially said it was "mist" from the breather tube. 15,000 street miles by a female rider (unless her name is Elena Meyers or Mellisa Paris), so no way are you getting "blow by" to the degree you suspect (fail #2 ) ... in my humble opinion.

It could be the case, i am just a bit more than skeptical that it's oil related. The symptom in my opinion is more along the lines of what Redsdead points out, and discussed some earlier, old nasty fuel in a bike that is not getting ridden much, and not getting ridden at high enough rpm enough..
 

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My bike hates me
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Correct me if im wrong, but doesnt the crank case breather go back into the airbox before the air filter which already has a thin film of oil on it therefore any "mist" of oil likely would not make it past the filter?
 
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