2000 VFR800FI performance problem

Hey guys, joined this forum not too long ago since I bought my first VFR! Very happy with it, the sound that V4 engine puts out puts a smile on your face every time.
The previous owner said he didn't ride it much at all, so its last service was some time ago. Given the bike's mileage (31k km) and price it didn't take me long to buy it. As soon as I rode it home I took it apart to give it a good service. The things I've done/replaced are:

- Air filter
- Oil filter/oil
- Brake/clutch fluid
- Checked/adjusted valves
- Coolant
- Tyres

A few valves needed adjustment and as this was my first time doing the valves on a shim-under-bucket type bike, I took my time with it, making pictures and marking the camshafts where they meshed together. After I was done with the valves I put everything back together, fired it up and synced/adjusted the SV's (with a carbtune). Ran and still runs very nicely at idle and responds to throttle well, no weird noises or anything.

However when I ride it, it seems as if the bike lacks power. This is especially noticeable at motorway speeds, when you open the throttle fully it doesn't really want to go very fast, quickly. As I'm not too far from the Autobahn in Germany, I decided to take it for a test ride there. In 5th gear the bike only just managed to get to 200 km/h on the speedo, in 6th it dropped back down to 180. I worried that somehow I might've messed up the camshaft timing by a tooth, so I tore everything apart again, rechecked valve clearances and checked whether the timing marks were flush with the head, they were.

So now I'm kinda lost on where to look. If the camshafts were indeed off by one tooth then I assume the bike wouldn't be running so well as it does, and only lacking in power? Also having checked them twice makes me think the problem must be somewhere else.
I did not test the bike at the same speeds when I just bought it, so don't really know whether it's always been feeling like this or if it's a new thing.

Perhaps an important note for any European members, the bike was imported from Belgium by the previous owner. Could it be that it's been restricted in a way? I did look for any intake restrictors or non-original throttle stop plates etc, but didn't find anything. Could it be ECU-limited?
Bike is completely stock.

Any help appreciated!

 

I'll focus on the ECU, perhaps try another if I can find one. Thanks a lot!

 

An update on my issue:

Replaced the ECU with a different one, however the problem still persists. Anyone got a clue where to look next?
Was thinking of blocking the PAIR valves to see if it makes a difference, since I've read they may cause performance problems when clogged up. Would this make such huge difference in power though? Also strange if they'd be completely blocked or something, given the bike's mileage. I've also put the bike on a dyno, to see what it puts out.. Only a mere 68hp, not really what it should be. ;p

Thanks for any help!

 

Could be starving for air.Did you replace with stock air filter?

 

Sounds like it could be a timing related issue...like it's not advancing properly but that should be controlled by the ECU....could there be anything that did not get hooked back up correctly?

 

Thanks for the replies guys.
I've ridden the bike yesterday and on two occasions when I went full throttle, it kind of surged at around 7 and 9k rpm. When it did that it felt like it had more power briefly, after letting go it was back to "normal".
Also tried to run it for a short while without air filter, to see if that was the problem. Nothing changed without it though.

Hmm, I'll take another look at the wiring. Are there any wires specific to timing, which could be easily missed?
Was thinking of unhooking the map sensor to rule out any faults from that, don't think it's related to it though.

 

What rpm does that VTEC mess supposed to kick in on them fuel erection bikes?

 

Was about to take it to a garage and have it looked at, so put all the fairings etc. back on. Then I saw that the vacuum hose coming from the fuel pressure regulator wasn't really free, it was being pinched by the bypass solenoid valve and its hoses/connector. Loosened it up a bit and the bike runs perfect now, accelerates well and gets to top speed easily. I must've overlooked it after putting back the air filter housing. Really happy with the bike now.

Again, thank you all for your advice!

 

Sometimes it's the simplest thing that causes a problem that has you baffled. In my line of work this sometimes has you chasing your tail for hours, then you realize you forgot to "initialize" the device! Glad that got sorted out for you.

Cheers!

 

Shows I would have been wrong. I thought maybe a plug wire was loose or coil wires. Glad you found it. Nothing worse than a mystery problem almost as bad as not being able to find your key