Honda Motorcycles - FireBlades.org banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I bought a 2007 VFR with only 1900 miles. Bike is spotless. I test rode it and didn't hear the noise it's now making. It's got a knock that intermittant. It sounds like it's at camshaft speed, but this knock comes and goes. Sometimes the engine knocks like crazy and then then next minute it's quiet as a mouse. Sounds like a wristpin knock, it's not a heavy knock like a con rod. And the severity of this knock varies too. Bike is most apt to start doing it after you've ridden it a little and then you shut it off for a bit. Start it back up and boom it's knocking again. Then as you ride it seems to go away. Seems like the hotter the bike gets and the more you ride the less you hear it.
2 0r 3 times I've also heard backfiring through the airbox before it got warmed up.
I've checked the plugs and the cam chain tensioners, that's it. This VTEC engine scares me to death so I don't mess too much with it.
Does anyone have any suggestions about this?
This bike has sat a lot in it's life, obviously 1900 miles since 2007 is practically nothing.
 

·
Super Moderator
Joined
·
32,034 Posts
I bought a 2007 VFR with only 1900 miles. Bike is spotless. I test rode it and didn't hear the noise it's now making. It's got a knock that intermittant. It sounds like it's at camshaft speed, but this knock comes and goes. Sometimes the engine knocks like crazy and then then next minute it's quiet as a mouse. Sounds like a wristpin knock, it's not a heavy knock like a con rod. And the severity of this knock varies too. Bike is most apt to start doing it after you've ridden it a little and then you shut it off for a bit. Start it back up and boom it's knocking again. Then as you ride it seems to go away. Seems like the hotter the bike gets and the more you ride the less you hear it.
2 0r 3 times I've also heard backfiring through the airbox before it got warmed up.
I've checked the plugs and the cam chain tensioners, that's it. This VTEC engine scares me to death so I don't mess too much with it.
Does anyone have any suggestions about this?
This bike has sat a lot in it's life, obviously 1900 miles since 2007 is practically nothing.

How long since the oil has been changed?
VTEC is a _very_ simple (and totally pointless) system so you don't need to be frightened of it.
It simply uses oil pressure to push pins into place to activate the other valves.
 

·
Registered
Joined
·
28 Posts
I used to own a 1995 VFR750, which, at idle, made an intermittent knocking noise. I bought it in '96 with only 3600 k's on the dial. I owned it two years and never had any mechanical issues as a result of the occasional knocking. This was obviously well prior to Vtec. I currently own a 2006 VFR800 (Vtec) which I bought brand new, and I haven't heard any knocking, but, it does emit an occasional 'ticking' sound at idle. It does need a service though, so maybe fresh oil may be the required medicine ;)
Personally, any weird noises made by VFR's are shrugged off as a VFR trait. After all, they're supposed to be 'legendary' in their reliability. ;)
 

·
Registered
Joined
·
2 Posts
Discussion Starter #4
Well, before I bought the bike, the previous owner took the bike to a dealer for a total inspection simply because it had sat so much during it's life. It passed with a clean bill of health.
2 days after I got it home we headed out on a nearly 1000 mile trip to some southern states, and half-way along on this trip is where I first heard it. It was very intermittent at that point. So when we got back home the FIRST thing I did was change the oil and filter. I used good Honda Pro GN4 per the manual, and a factory Honda filter. It made no difference. If anything, at this time the knock is much more consistent than it was, and at times very loud.....I am talking embarrassingly loud because I know others can hear it.
This isn't some VTEC normal noise, this is something wrong in the engine. I have done search after search after search on the web about this, and my problem just doesn't exist. The only thing I found is a claim that throttle bodies out of synch will cause a knock. This may be true, but the knock I hear sounds more severe and detrimental than some fueling issue could cause.
Love the bike though, I mean I absolutely adore this machine. I just don't want to have to spend a fortune to diagnose and fix this thing. I mean, I will obviously if I must, but on a 3100 mile machine should I really be having a problem like this?? I'd say not. This bike was hardly ridden during it's life, and it was garaged, covered, and the minimal service done by the previous owner (which amounts to the inspection I spoke of and 1 oil change) was always done by the local dealer, I called the dealer to verify this. It's a pristine bike and thus the reason I bought it. Like I said, since 2007 he only put 1900 miles on it.
 

·
Registered
Joined
·
5 Posts
Howdy,

My 2004 VFR has the same issue. Almost 28k miles on it, 21k by me (spring/summer/autumn commuting over 6 years).

I had it checked over by a VFR expert here in Scotland (at a cost of almost 800 GBP) and he could find no mechanical issues although he did hear the sound. His recommendation - 'just rag it' (translated: try to visit the red line whenever you can ;-) )

Interestingly in this saga:

- The noise first appeared 2 years ago. Noise would appear a few minutes after cold start and be annoyingly loud for about 10 minutes until running temperature and then disappear.
- Then towards the end of the year (around October) the noise cycle changed from not being there from a cold start then appearing when engine was at running temperature and remaining until engine went off. This prompted the expensive investigation.
- This year it's back to it's old ways, noisy at start then gone at running temperature.

It sounds like a loud slap at the front right top side of the engine (while sitting on the bike). This area was checked and nothing out of the ordinary was found.

The engine is really good, lots of power (the Powercommander PCV5 helps though). If performance was poor or engine rattley then I would have changed it.

Hope this helps...
 

·
Registered
Joined
·
1 Posts
Howdy,

My 2004 VFR has the same issue. Almost 28k miles on it, 21k by me (spring/summer/autumn commuting over 6 years).

I had it checked over by a VFR expert here in Scotland (at a cost of almost 800 GBP) and he could find no mechanical issues although he did hear the sound. His recommendation - 'just rag it' (translated: try to visit the red line whenever you can ;-) )

Interestingly in this saga:

  • The noise first appeared 2 years ago. Noise would appear a few minutes after cold start and be annoyingly loud for about 10 minutes until running temperature and then disappear.
  • Then towards the end of the year (around October) the noise cycle changed from not being there from a cold start then appearing when engine was at running temperature and remaining until engine went off. This prompted the expensive investigation.
  • This year it's back to it's old ways, noisy at start then gone at running temperature.
It sounds like a loud slap at the front right top side of the engine (while sitting on the bike). This area was checked and nothing out of the ordinary was found.

The engine is really good, lots of power (the Powercommander PCV5 helps though). If performance was poor or engine rattley then I would have changed it.

Hope this helps...
What I did because I have a 2007 VFR VTEC 800 rr change to 10/40 weight tfollowed by Lucas oil additive a few days you will never here that noise again I don’t open Honda motors very different I have the same problem as you guys have trust me 10-40 heavier oil stops all That even the manual says to switch to 10-40 at certain temperatures
 
1 - 6 of 6 Posts
Top