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View Full Version : Carb balancing...



ldnz
22nd May 2007, 16:31
I believe it is time the 6 got its carbies squared away. I have but one vacuum gauge, and have never done this before. Does anyone have a set I could borrow, or even better, give me a hand to do the job? I hear its not a major, and i'd be happy to pay in beer!

vifferman
23rd May 2007, 08:45
I've lent my gauges to slopster - I'll PM him to give them to you when he's finished with them. If he can't help you out with the balancing, I can (I live on the Shore too).

slopster
23rd May 2007, 15:05
Yeah I've finnished with the guage thanks mate. While I was doing it I found my fuel pump was leaking fuel onto the hot engine so I won't be riding til I get that sorted. Ldnz I can drop them off to you want and point you in the right direction - reasonably simple but fiddly job. I'm going to be away for a couple of weeks from saturday so I'll need to drop them off by then. I've got friday off if that suits but I've got some other stuff to do as well.

vifferman
23rd May 2007, 15:15
Thanx, Mr Slopster. Did they work OK?

Look, Mr ldnz - I'm willing to help you, but just be aware I'm a bit unreliable at the moment. I've developed a unfortunate habit of wanting to do things, having good intentions, but then failing to deliver on offers/promises made. If Mr Slopster can't help you, I'll try to. I know what to do ("Trust me - I know what I'm doing!"), but sometimes don't get around to doing it.

slopster
23rd May 2007, 15:58
Well I found that even when you set them the same they wouldn't always go back to exactly the same spot. Good if you bikes way out but a bit tricky for the fine tuning side of things especially on a 4 cylinder. Next time I'll just use an improvised water tower one. Bit of a hassel but 100% accurate.

vifferman
23rd May 2007, 16:08
Does that mean that your bike's carbs are now not balanced properly?

I found that even using the mercury ones (Carbtune?) to synchronise the starter valves on the VFR it was hard to get them just right. Every time I'd adjust one valve, another one would alter, so I was continually chasing my tail. Plus I didn't have an accurate tachometer, and the specs call for 1100 rpm +/- 50, hard to do when you know your tacho is out by up to 400 rpm (Honda design feature).

ldnz
23rd May 2007, 16:21
Cheers guys. I found the haynes manual for my bike specifies that they should be within 2.5cm of Hg of each other. By the way - how does this affect the engine? I'd assume its going to be of greatest benefit at idle and small throttle settings. Does it reduce vibration, make for smoother running?

vifferman
23rd May 2007, 17:03
I'd assume its going to be of greatest benefit at idle and small throttle settings. Does it reduce vibration, make for smoother running?
Yes.
Should do.

slopster
23rd May 2007, 17:35
Na I got it ballanced pretty well in the end. Just got a bit frustrated along the way like you said chasing your tail and all. Ldnz PM me or phone 0211163683 so I can drop that guage off to you.

Max Preload
25th May 2007, 00:21
You have to balance the carbs at a fast idle otherwise the slow pulses will often upset the readings... and if the vacuums indicated don't return to the same place after you blip the throttle there might be some play in the spindles.

vifferman
25th May 2007, 09:26
You have to balance the carbs at a fast idle otherwise the slow pulses will often upset the readings.
The gauges have adjustable damper valves, which you can turn till the needles stop quivering.

Max Preload
25th May 2007, 09:47
The gauges have adjustable damper valves, which you can turn till the needles stop quivering.

Yes - but applying damping at normal idle will also affect the readings, not just damp the pulses.