Sound of my VFR at idle

Hi guys,

New 99' VFR owner here. My VFR makes a very unnatural sound at idle. Its not smooth and there seems to be engine noises that don't sound right. I went ahead and changed the spark plugs, oil, and coolant.

I made a youtube video of the bike at idle. Just a note, that I do have the air filter off of my VFR at the moment.
https://www.youtube.com/watch?v=rzEdSOsgEX4

This is another youtube video I found that has a VFR in it that sounds much better
https://www.youtube.com/watch?v=mBepfKqZRPE

Any ideas as to what could be wrong? Check the valves maybe?

 

They do make a unique sound at idle, but yours sounds really different. The sound recording doesn't help. Try again to record it outside to loose the echo.The silver one sounds right.

 

Just a quick update, I believe I found the source of the bad idle noise. Actually two sources.

I removed the airbox from the motorcycle and noticed that there were two rubber L shaped tubes that weren't connected to anything and were just sitting around the throttle body. I believe they have something to do with the vacuum system. I reconnected them to the airbox and the throttle body. This would probably also explain why my mileage was only around 32 mpg when I was expecting around 38 mpg since I ride pretty conservatively when commuting. For reference the two L shaped hoses are part #4 in this diagram. partzilla

The other source is more interesting. I noticed water coming out of the bike where the muffler connects to the rest of the exhaust system. Turns out there is an exhaust leak. Probably because one of the previous owners had an aftermarket exhaust and decided to put the stock one back on. Only the exhaust clamp does not fit around the holes at the end of the stock muffler and there seems to be a gasket missing which is referenced in part #7 in this diagram. partzilla. I am going to have to do some more research on this one and find out how the stock muffler is supposed to go on.

At least the airbox problem is solved. Ah the perils of buying a used bike... It fun to figure it out though and hopefully my experience helps others.

 

All the hoses need to fitted to the airbox else a vacuum leak will cause incorrect idle.
Also sync the starter valves to make the idle and starting correct.

 

...and don't run the bike without a filter...felling is set taking a filter into account. Apart from airborne crap going down the throttle body it will probably run very lean.
Where the silencer and collector meet there is a thick grey gasket that has a weird lubricated feel to it. You'll never get a gas tight seal without it.

BTW a gallon of fuel produces a gallon of water...all that vapour you see on a cold morning, water dribbling from tail pipes in town, puddles under the bike from exhaust joints and drain holes.

 

Do you know how this gasket actually fits? I noticed that partzilla references a clamp that has one bolt. I have a clamp with two bolts on it and that seems to match the service manual. Funny thing is that the manual doesn't reference the gasket at all.

 

Hi, yeah, nothing to it. The gasket goes into the silencer then slide the silencer onto the end of the collector as in the photo. Tighten clamp. Done!

Just handle the gasket with care as it's easily damaged.

 

My VFR also has a clamp with two bolts. Use copper anti seize grease on the gasket, and if you need to open up the muffler pipe so it slips easily over the gasket.


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So after changing the spark plugs, oil, coolant, air filter, making sure that the hoses to the air box are fitted, and putting on a new exhaust gasket, the bike runs so much smoother and the idle has quieted down a bit. I am going to look into doing the valve adjustment and starter valve sync soon but so far I'm very happy with my bike.