[ashis89]

I have a query. My FNG (at Bhubaneswar) has the habit of 'oiling' the bike silencers by pumping old engine oil. He says they turn dry after prolonged use and sound hoarse. They also tend to rust and the burnt engine oil prevents it. He used to do it in my old P150 once in a few months and indeed the exhaust note sounded smoother. He mostly used the small hole at the bottom of the silencer and a couple of pumps of the oil can in the main exhaust hole. The performance was not affected and bike ran like a charm till 43k kms until it was sold.

When I bought my Pulsar 180 in Bangalore ( I am back in Bhubaneswar now) and asked a FN Catrol Bike Point to do the same during one of the paid service, he was aghast. He said it would ruin the silencer and the engine too and refused to do it. Since then I have never put oil in my bike silencer.


Off late I have noticed that my bike's exhaust note is slightly hoarse. I was wondering if my mechanic's idea was indeed correct or does it really the silencer? I have seen this being done on my old Caliber 115 by my previous FNGs in my earlier cities of residence. The results were much more prominent and the bike exhaust note went super silent (almost like a Unicorn ) for almost a month or so. The performance was the same as earlier. Any suggestions?

[Rash]

No need to put used oil into your exhaust system. Your exhaust will be coated by soot on the inside within a few hundred KM's of driving around since new.

Generally moisure will cause rust and most exhausts will rust from the outside based on the humiditiy/salinity in your area.

I dont see how pouring oil into your exhaust will help anything. Even if you do, a few squirts will not harm the engine, but might destroy your catalytic converter.

[ArizonaJim]

ashis89

I find it more than a little ironic that you have the comment at the bottom of your post that says:
"Smoking is injurious to health. Don't let your car smoke through its exhaust." .

Smoking is exactly what adding oil to the inside of your silencer will cause.

Adding a small amount of oil should not damage anything other than the atmosphere behind you and, as Rash mentioned, your silencers catalytic converter if your motorcycle has one.

Adding a large amount of oil on the other hand will cause it to be turned to carbon from the heat of the exhaust.
The carbon buildup will not prevent rust. It will however plug up the small passages inside the silencer hurting your engines power.
These passages are needed to let the engines exhaust out easily.

As many of you know, the two stroke engines constantly add oil to the exhaust so they emit oil vapors that would eventually turn to carbon and plug up their silencers, robbing the engine of horsepower.
It had to be removed periodically to restore the lost power.

Adding oil to your silencer will do the same thing over time so I would not recommend adding new or used oil to it.

[sharanvenu]

I have one more thing to add. The added oil in the silencer will solidify after some thousand kilometers. This will come off the surface of the silencer (inside) and cause clanking noise which will be very irritating. It is better to replace the silencer in the event of severe rusting to conserve the best engine performance. Normally modern silencers last well above 10 years I guess. I have no idea about the cost of a new silencer though. Should be in the order of 5000 INR at the max for any 150 cc machine. Please correct me if I am wrong.

[ashis89]

Thanks for your replies. Even I was of the same opinion initially and even used to point out to people if there was smoke or oil in the exhaust of the 4-stroke. But then multiple mechanics at multiple garages in multiple cities followed this practice and made me accept the idea. But I went through the manual and also inquired at Bajaj ASS while purchasing my P180 and have since then strictly prohibited my FNG from putting any oil into my current bike's silencer.

Sharanvenu, to give you a perspective, the silencer for a P150 used to cost ~3100 about 4 years ago.

[saket77]

Originally Posted by ashis89

Thanks for your replies. Even I was of the same opinion initially and even used to point out to people if there was smoke or oil in the exhaust of the 4-stroke.

In my opinion, burning of engine oil will result in a lot more carbon formation. Definitely not good for power output.

Originally Posted by ashis89

Sharanvenu, to give you a perspective, the silencer for a P150 used to cost ~3100 about 4 years ago.

High cost of the silencer muffler can be attributed to the presence of catalytic converters in them. The metals used inside which act as catalyzers are quite expensive.