Author Topic: carb balancing? (Read 16584 times)

darrsi · « **Reply #50 on:** 30 July 2013, 07:26:33 pm »

Quote from: Yamazer-92 on 30 July 2013, 07:05:52 pm

Ah right I see what you mean now, do you need anything under the tank like a block of wood to hold it up for some clearance?

I actually put a foam knee mat across the battery thinking it would sit on that but it didn't even touch it, so no not really.
Although covering the battery wasn't a bad idea anyway just in case of any accidental leakage.
Make sure you secure it though, even though it appears to sit quite happily on its own.
Always safety first when fuel is involved.

Yamazer-92 · « **Reply #51 on:** 02 August 2013, 09:30:30 pm »

Well my carbtune arrived in the post today so I went for it. Followed the guide which was brilliant because I couldn't even see the left and right adjustment screws at first, then when I did I sobbed a little at how ridiculously hard they are to get to especially the right. Got there in the end though after a trip to toolstation for a foc off long screwdriver. Got them all within the 2 cm spec, although they do bounce around a little but they were all within the lines and level so I was happy with that. I finally did the TPS as well and set it to 5k. Bike feels great at low revs now, a lot smoother. Would definitely recommend anyone considering doing these 2 jobs to get them done because you won't regret it.

darrsi · « **Reply #52 on:** 02 August 2013, 10:05:02 pm »

Quote from: Yamazer-92 on 02 August 2013, 09:30:30 pm

Well my carbtune arrived in the post today so I went for it. Followed the guide which was brilliant because I couldn't even see the left and right adjustment screws at first, then when I did I sobbed a little at how ridiculously hard they are to get to especially the right. Got there in the end though after a trip to toolstation for a foc off long screwdriver. Got them all within the 2 cm spec, although they do bounce around a little but they were all within the lines and level so I was happy with that. I finally did the TPS as well and set it to 5k. Bike feels great at low revs now, a lot smoother. Would definitely recommend anyone considering doing these 2 jobs to get them done because you won't regret it.

I used a cheap 4" flat blade on the right side, it was much easier.

Yamazer-92 · « **Reply #53 on:** 02 August 2013, 10:39:38 pm »

Funnily enough that's what I did too, couldn't get the phillips onto the threads at all and had enough room on the right to get the shorter flathead I have down into it. The middle and left screw needed the long phillips though. Runs a hell of a lot sweeter now. Wouldn't be scared to do it again next time it needs doing either, wasn't as difficult as I imagined once I had all the correct tools.

Dead Eye · « **Reply #54 on:** 03 August 2013, 11:56:12 am »

Undertaken this task again today (3rd times the charm) after forgetting all about the restrictors on my previous attempts.

The issue I have is that they are completely out of spec - I can sync them up but they all sync to about 19-20 cmHg whereas the spec says 23-25

I'm also pretty certain that cylinder 1 is the culprit in some way. If I adjust the centre screw in favour of 3+4 the revs rise and so does the cmHg across all cylinders - this is an even increment across 3+4 then a slightly lower on 2 and only very slight increment on 1. Same sort of circumstance if I adjust the left hand screw (for 1+2) in favour of 2. 2 obviously rises but so does 1, just at not such an extreme rate. With 3+4 if I adjust then one will drop about as much as the other increases, which is what I expect to happen

So basically, what the crap is going on with cylinder 1?! I unfortunately don't know enough about the importance or meaning of these measurements to start building up a prognosis

mickvp · « **Reply #55 on:** 03 August 2013, 03:58:30 pm »

if you wind all 3 screws in/out, the overall vaccuum should move?

Punkstig · « **Reply #56 on:** 03 August 2013, 06:39:54 pm »

Quote from: Dead Eye on 03 August 2013, 11:56:12 am

Undertaken this task again today (3rd times the charm) after forgetting all about the restrictors on my previous attempts.

The issue I have is that they are completely out of spec - I can sync them up but they all sync to about 19-20 cmHg whereas the spec says 23-25

I'm also pretty certain that cylinder 1 is the culprit in some way. If I adjust the centre screw in favour of 3+4 the revs rise and so does the cmHg across all cylinders - this is an even increment across 3+4 then a slightly lower on 2 and only very slight increment on 1. Same sort of circumstance if I adjust the left hand screw (for 1+2) in favour of 2. 2 obviously rises but so does 1, just at not such an extreme rate. With 3+4 if I adjust then one will drop about as much as the other increases, which is what I expect to happen

So basically, what the crap is going on with cylinder 1?! I unfortunately don't know enough about the importance or meaning of these measurements to start building up a prognosis

how gentle are you using the screwdriver- you should be trying your damned best not to be pushing on it at all as this will affect the gauge readout, also after every little adjustment blip the throttle and re read the gauges, its this that makes adjusting time consuming!

Dead Eye · « **Reply #57 on:** 03 August 2013, 10:23:21 pm »

Quote from: mickvp on 03 August 2013, 03:58:30 pm

if you wind all 3 screws in/out, the overall vaccuum should move?

For some reason I hadn't considered this... must be my bad day

Punkstig - I was using very little pressure as I know that if you push down it affects the readings and always blipped the throttle between adjustments

Unfortunately the bike and I had a slight accident which resulted in the front end being destroyed on a ride this afternoon so it seems all my fettling was in vein as its off the road until I can fix it up

darrsi · « **Reply #58 on:** 04 August 2013, 08:16:43 am »

Quote from: Dead Eye on 03 August 2013, 10:23:21 pm

Quote from: mickvp on 03 August 2013, 03:58:30 pm
if you wind all 3 screws in/out, the overall vaccuum should move?

For some reason I hadn't considered this... must be my bad day

Punkstig - I was using very little pressure as I know that if you push down it affects the readings and always blipped the throttle between adjustments

Unfortunately the bike and I had a slight accident which resulted in the front end being destroyed on a ride this afternoon so it seems all my fettling was in vein as its off the road until I can fix it up

WHAT????

darrsi · « **Reply #59 on:** 04 August 2013, 08:30:48 am »

"....Unfortunately the bike and I had a slight accident...."

You fell over that cliff didn't you?

Dead Eye · « **Reply #60 on:** 04 August 2013, 09:07:49 am »

I may as well have

I'm certainly out of commission for a few days, the bike probably longer...

http://foc-u.co.uk/index.php/topic,8908.msg92310.html#msg92310

JoeRock · « **Reply #61 on:** 04 August 2013, 04:27:14 pm »

Quote from: Dead Eye on 03 August 2013, 10:23:21 pm

Quote from: mickvp on 03 August 2013, 03:58:30 pm
if you wind all 3 screws in/out, the overall vaccuum should move?

For some reason I hadn't considered this... must be my bad day

Punkstig - I was using very little pressure as I know that if you push down it affects the readings and always blipped the throttle between adjustments

Unfortunately the bike and I had a slight accident which resulted in the front end being destroyed on a ride this afternoon so it seems all my fettling was in vein as its off the road until I can fix it up

It doesn't matter mate what they're on as long as they're all close!

mickvp · « **Reply #62 on:** 04 August 2013, 05:10:47 pm »

Quote from: JoeRock on 04 August 2013, 04:27:14 pm

It doesn't matter mate what they're on as long as they're all close!

The Haynes book of lies says all 4 reading when balanced should be between 230 to 250 mmHg.

elbrownos · « **Reply #63 on:** 04 August 2013, 10:21:29 pm »

Seems pointless to specify something that can't be adjusted

darrsi · « **Reply #64 on:** 04 August 2013, 10:34:57 pm »

Would it not indicate that something is amiss if you're not within spec?

Yamazer-92 · « **Reply #65 on:** 04 August 2013, 10:48:44 pm »

I can't remember what numbers the gauges were at when I was doing it, it was 20 something but in the instruction booklet it said that it doesnt matter what number it is at particularly as long as they are all level and within 1-2 cm of mercury. Mine is running nice and smooth now but have I done it wrong by not getting it within 230mm or whatever it is?

darrsi · « **Reply #66 on:** 04 August 2013, 11:01:31 pm »

Quote from: Yamazer-92 on 04 August 2013, 10:48:44 pm

I can't remember what numbers the gauges were at when I was doing it, it was 20 something but in the instruction booklet it said that it doesnt matter what number it is at particularly as long as they are all level and within 1-2 cm of mercury. Mine is running nice and smooth now but have I done it wrong by not getting it within 230mm or whatever it is?

It's in relation to the measurements listed on the Carbtune, not a physical cm of the rod.

It should be within 10mmHg (dunno what that means?) so would actually need to be within two of the smaller lines.

Okay, just learnt that Hg is the chemical symbol for mercury, i never knew that!

mickvp · « **Reply #67 on:** 04 August 2013, 11:05:59 pm »

Hg is the chemical symbol for mercury, it just means the vacuum required to displace 10mm(3) of mercury.

As I said earlier, I was under the impression if you moved all 3 screws an equal amount, you could achieve the overall level of vacuum as laid out in the Haynes manual. I'm not sure how much it matters though, although mines is where it should be.

darrsi · « **Reply #68 on:** 04 August 2013, 11:11:32 pm »

Quote from: mickvp on 04 August 2013, 11:05:59 pm

Hg is the chemical symbol for mercury, it just means the vacuum required to displace 10mm(3) of mercury.

As I said earlier, I was under the impression if you moved all 3 screws an equal amount, you could achieve the overall level of vacuum as laid out in the Haynes manual. I'm not sure how much it matters though, although mines is where it should be.

Yeah, my photo' on the previous page puts mine in the good books too, although i've adjusted it again since then and it's even better now.

Took the bike out for a spin today after refitting my Moto GP exhaust and it felt and sounded awesome, and was pulling like a train.

Dead Eye · « **Reply #69 on:** 04 August 2013, 11:13:36 pm »

Well mine was running better with them all balanced correctly (even with the low vacuum) up until my little fight with a corner...

Hedgetrimmer · « **Reply #70 on:** 04 August 2013, 11:14:10 pm »

When I've balanced carbs in the past, I've just been concerned with getting a level reading across all four, and didn't used to worry too much what that reading was. With wear and tear on higher mileage engines, I believe it would become more difficult to ensure that the actual reading would be perfect anyway. The goal is to get the bike running as smoothly as you can and not worry too much about whether or not you are perfectly "on spec". Obviously if you are no where near the recommended settings you may have another problem, but this would probably manifest itself in other noticeable symptoms anyway. I also seem to remember that you usually have one "reference" carb, and I seem to remember that this one doesn't usually respond in quite the same way as the other 3. But it's a while since I've done this myself, and perhaps my memory is a little cloudy.

Actually, come to think of it now, on some bikes the reference carb is not adjustable?

darrsi · « **Reply #71 on:** 05 August 2013, 06:05:35 am »

Quote from: nick crisp on 04 August 2013, 11:14:10 pm

When I've balanced carbs in the past, I've just been concerned with getting a level reading across all four, and didn't used to worry too much what that reading was. With wear and tear on higher mileage engines, I believe it would become more difficult to ensure that the actual reading would be perfect anyway. The goal is to get the bike running as smoothly as you can and not worry too much about whether or not you are perfectly "on spec". Obviously if you are no where near the recommended settings you may have another problem, but this would probably manifest itself in other noticeable symptoms anyway. I also seem to remember that you usually have one "reference" carb, and I seem to remember that this one doesn't usually respond in quite the same way as the other 3. But it's a while since I've done this myself, and perhaps my memory is a little cloudy.

Actually, come to think of it now, on some bikes the reference carb is not adjustable?

I wonder if that's carb #1 then, 'cos it didn't appear to move much when tweaking it?

Hedgetrimmer · « **Reply #72 on:** 05 August 2013, 07:33:33 am »

If there is a reference carb on the FZS, surely it must refer to it in the manual? Again, this is from a rusty memory, but usually I think it's 2 or 3. But my experience is also with older Kawa***i fours (z650s &c) so may not be 100% relevant here.

darrsi · « **Reply #73 on:** 05 August 2013, 09:23:34 am »

I think it just said balance 1 & 2 first, then 3&4, then balance them together to level them all from memory.

Dead Eye · « **Reply #74 on:** 05 August 2013, 09:56:27 am »

There is no reference carb on the Fazer as all 4 are adjustable. A reference carb is usually used when each carb is independently adjustable of the others. On the fazer, there are three adjustment screws, but each affects at least 2 carbs. So as we know; Left balances 1 and 2, Right balances 3 and 4 and Middle balances 1+2 against 3+4