Q: I have a Honda VFR800 VTEC, 2002 model, with 35,000km on the clock that has started to vibrate above the VTEC threshold after a day on a go-kart track. There were a few visits to the rev-limiter but no violent downshifts. These vibrations are noticeable in the seat, hands and feet between 7,000 to 8,500 rpm but seem to go away above and below this, there were no vibrations before the track day.
The bike has a ‘slip-on’ silencer and the PAIR, snorkel and flapper valve modifications done by PO otherwise, as far as I know, it’s stock.
So, any ideas what could cause this and where should I start to look while trying to fix this?
A: This is a difficult one without having the bike in front of us. But first take off the air-box lid and have a good look inside to see if anything has come loose, seeing as mods have been made in there already.
It might be one cylinder has begun to give problems that would certainly cause vibration problems due to the imbalance this would cause, so perhaps a compression test might be a good start. You might want to check to see if the throttle bodies have gone out of sync as well, but that would possibly mean a visit to a Honda dealer.
We’ve also heard of voltage problems with this bike so make sure the battery is healthy as well?
Hope these pointers help and maybe have a check around various forums around the Internet world to see if anyone has similar issues?
Q: I was recently at a National superbike race and got talking to some of the guys who race the BMW S1000RR, mainly because I have one.
They told me that they tend to change the cam timing on their race bikes, but cannot change the actual camshaft itself. I did ask them if it makes any difference to performance but all I got was raised eyebrows and pathetic grins.
So, could you guys tell me the benefits of doing this and is it really worth fiddling around with mine, I only use my bike on the road for fast breakfast runs? Looking forward to your response seeing as you seem to know everything around these matters.
A: As a rule, if you change the cam timing of the stock cams, it doesn’t really make any more horsepower or maybe a few depending on where they’re set. What it does do is move the power around depending on the track. So, for example, you may achieve more midrange or a bit more top-end and then possibly lose out on the stock mid-range settings. The original camshaft is what BMW believe to be the perfect compromise to begin with.
So, if I were you, I’d just leave the factory settings alone for road riding and spend your money on something else instead. Hope that clarifies thing for you?
Q: On the new 2016 Kawasaki ZX-10, which is already very expensive at R290,000 (thanks Zuma dude!), there is a factory option of fitting a different/replacement ECU and, apparently, it also has to have a completely different wiring loom to go with it as well!
Now the price of this addition is, I’ve been told, 50k! Now that seems to be a lot of money after spending close to 300k to start with, right?
So what are the benefits of going this route with what is already claimed to be the best ever 1,000cc superbike ever made, well for this year at least?
Great site as well, by far the best we have in South Africa.
A: The ECU you’ve mentioned allows the Kawasaki to have more race mode features, which will really only be beneficial during race conditions and not necessary for ‘normal’ use.
Once fitted it allows the ZX-10 to have ‘auto-blip’ downshift and more programmable options for the engine, like engine braking, rpm limiter, shift delays for the quick-shifter, and, and, and…
But for 50k more it’s not really necessary unless you can ride it as hard as Johnny Rae for example. And we all know how much it costs to go racing to high levels and try to save valuable seconds in the process, hence the shocking price of this addition.
Q: I own an old 1981 Suzuki GS1000 G, the one with the shaft drive. It’s covered, well… I have no idea really because the speedo has broken, and I fitted a new cable but it still doesn’t work. But that’s not why I’m sending this.
The bike doesn’t charge so the battery is always dead. YES; I put in a new battery but it’s still not ‘playing’ nicely.
So basically ‘know-it-all’ dudes, what are my options and what can I do to get some voltage out of the old girl?
A: Well, you either have a faulty stator sitting behind the left side engine cover, which needs to be checked by a decent electrician to be sure. You won’t have to buy a new one, if so, because they can be repaired. Or, more than likely, it’s the regulator/rectifier unit, they break, a lot.
That can also be checked easily to see if it’s malfunctioning. Go onto the Internet and many people will tell you how to do so. If so you’ll have to replace it with either a used one from a breakers, or buy a new one. The genuine Suzuki part will be horrendously expensive so check on the Internet for replacement alternatives, there’re many?