[digitalnerd]

I recently got the 5th servicing done for my Apache 160 4V. It does not run a lot (~2200 KMs so far) and I only get the engine oil changed during alternate services (i.e. every six months). It was done last time, so I asked the advisor to skip it. He then told me that brake pads need to be checked and talked about some engine decarbonization that will depend on spark plug state. I told him brake pads would be fine since it has not been run enough for them to be worn off. About the decarbonization I told him to show me what he's talking about since I was waiting for the job to be done.

I was there the whole time and the engine oil levels were fine and brake pads were good too. The advisor came and spoke to the mechanic a couple of times but didn't say anything to me. I may have spent some time on the phone but I didn't see any extra work being done.

When the time for billing came, they invoiced me for engine decarbonization and engine oil top-up. I flatly told that no engine oil was added and I was there the whole time. They verified and removed it. But, they kept saying that engine decarbonization was done using a spray (Photo attached) that costs 450 bucks per treatment!

I told them that I wasn't consulted and they should have called me. The advisor then said something about the mechanic doing it while he had gone on a test ride or something and that it was done by spraying into the spark plug cavity or some such thing. He shows me this spray bottle that has an MRP of 2680 and says it only lasts for 3-4 bikes. I told him that if it lasts only three sprays then they incur ~ 900 Rs per spray. Anyways they wouldn't reduce it saying the prices are fixed in their software and such. I was getting late and I generally had a good experience at this service center during the previous 4 services. So I paid and left.

The bike does feel a bit smoother but it could just be the chain tightening and lubing that was done after washing. It was 450 Rs item on a 550 Rs total bill. I feel that I was cheated here but does anyone else have experience with this stuff? Should I flat out refuse these things during subsequent visit?

[vj_torqueaddict]

Welcome to the forum!

Yes its a scam. There are tons of articles on this forum related to the same, please search for the keyword "engine decarbonisation".
Please do familiarise yourself with the owner's manual. It will also have service interval schedule and what parts has to be replaced or serviced at each intervals. Your technician should not deviate from it at any cost.

All the best!

[MT_Hyderabad]

When I bought my second bike in 2011, in the first service itself I was charged for oil filter which was not changed. I asked them that it was not changed, and they acknowledged that it should be changed but they didn't have it in stock! Really, not having an oil filter for Yamaha Fazer (Fz16 lineage) when these are the bikes which were selling like hot cakes at that time.
I didn't get any service from Yamaha thereafter. People were claiming that the warranty will be voided etc., but I didn't care.
Stop going to authorised service center, get services done from a nearby garage. They won't charge these things.

Related to your specific query: if it is not mentioned in the manual, it is a scam.

[drt_rdr]

It's a carburettor\fuel injector cleaner, it's mentioned on the back of the can. I don't know why the service centre would use it on a low-run, less than 2 year old bike, that too claiming it's to "decarbonize" the engine.

Next time, sternly refuse to pay if they do such things without informing you. Be wary of engine oil additives too.

[tez_padhye]

Please read your service manual. And follow the scheduled jobs as per kms run, not time since last service. Change your engine oil according to the mileage on the oil. The oil will protect your engine for up to 1.5 years so if your mileage on your oil is less than 2000km, you can skip changing it up to 1.5 year.
As for these performance and mileage enhancing sprays and additives, run away from them.

[sagarpadaki]

Just fill in premium petrol from HP/IOCL/BP and go on a ride for 100 kms. It will have the same effect as whatever that spray can does

[gharika]

The packaging seems to be a local make not branded scam item where they can apply any price on the label. That is your biggest hint for the scam. Anything not in the service schedule is a way for the service center to make more money.

[vedirah]

Engine decarbonisation isn't entirely a scam. Sometimes it is needed for certain types of engines, especially two stroke engines and direct injection engines. The idea is to remove the carbon deposits in the combustion chamber. Why do we need to remove the carbon deposits? Let's have a look at the engineering behind this:

An ICE engine works on the principle of producing controlled explosion within the combustion chamber. This explosion is created by injecting air-fuel mixture in the chamber, and using a spark plug to ignite this mixture. Usually, in a new engine, the flame front generated by this process starts at the spark location and gradually moves towards the edge of the chamber (called laminar flow in fluid mechanics parlance). This is what's expected, because a flame front that gradually moves creates an even pressure on the piston head. In engines that have carbon build-up, the flame front behaves differently. Because the carbon deposits get heated up during regular running of the engine, the high temperature deposits can act as their own flame source. Ideally we want the flame to start at the spark plug and move towards the edge. But when carbon deposits create their own flame front in addition to the one created by the spark plus, these opposing flame fronts can collide and create an uneven distribution of pressure on the piston head, and likely result in turbulent flow. This is called an uncontrolled explosion. What are the effects of this uncontrolled explosion? - firstly, the difference in temperature gradients means some of the fuel remains unburnt, which causes a further build up of carbon in the chamber. Secondly, it puts side-ways pressure on the piston head causing the piston rings to 'dig into' the cylinder walls. Thirdly, it can cause temperature spikes which can damage the injectors, the spark plugs and even the valves. Fourthly, there's the issue of increased vibrations.

Now, having said all that, it is highly unusual to do this decarbonisation on a practically new engine. If the mechanic feels that there is carbon build up in the chamber, I'd be more worried about why this is happening in the first place. There could be several reasons:

1. Spark plug is not clean, or is not positioned correctly, or is somehow damaged. That's seems very unlikely.
2. The air fuel mixture isn't proper - the injectors are failing or the fuel pump is failing.
3. Oil is leaking into the combustion chamber.
4. Valves are not opening and closing properly.
5. The exhaust system has some restriction due to which there is excessive back-pressure.

These are some reasons I could think of and should be easily diagnosed by any proper technician. I don't understand how these issues could crop up in a practically new engine. So yes, it could be a rip off, or something is very wrong with the engine that you have. I'd press for more information on this. Carbon build-up, based on the location within the combustion chamber, can lead to catastrophic engine failure. I'd advise you to get it checked with a competent garage. Then again, I don't want to advise you to get the engine disassembled for what could possibly be just a scam. It's your call