Tuning Question

I've been working with Mark trying to get my 2013 8V GRiSO with Zard (no catcon but with dbk) running properly. Mark has been great with many map variations and a constant willingness to help, but we decided I may have a tuning issue (most likely TB's out of balance). I had a steady throttle surging with the stock can and with the Zard. I was due for first service, so decided to put the stock can back on and stock map back in for that. I picked up the GRiSO after first service and had a 60 mile ride home. The tech claimed my TB's were in balance and were not touched. TPS was out by a hair and re-set. Valves were loose and he adjusted on the "snug" side of tightest tolerance. He did not "notice" any issues with my evaporative system. My problem -- much more vibration than before. Could tightening the valves make that much of a difference?? The vibration had my attention so much that I did not notice the steady throttle surging anymore. The tech seemed competent, but I really am at a loss as to why the bike vibrates more than before....everywhere. Can I live with it? Sure.....but I want the bike to run as well as possible and it certainly did not vibrate as much before the service.

Any suggestions? I assume to try TB balance on my own? Carbtune or Carbmate? Any preference?

Anything else?

Thanks in advance.

What about C02's at idle?

I'm partial to the Morgan Carbtune, caveman simple and nothing to break or go tits up.

While the newer bikes do tend to be set up better than earlier models I still have not found one that came from the factory *Right* or that didn't need a tweak at almost every service.

Ex factory they STILL tend to be delivered with both air bleeds open. Why such a basic mistake is made I don't know? Perhaps they are just pulled off the rack and fitted assuming that the flow bench settings from Magnetti Marrelli are good enough? Who knows?

It should be remembered though that every time the bike is serviced little things like the valve clearances being set WILL make a difference to things like TB balance. Changing the clearances changes the valve timing. The tighter the clearance the longer the duration and grater the lift of the valves, (Although the effect of the latter is tiny the effect of the former is certainly noticeable.).

Since the clearances are set purely by 'Feel' there will always be slight discrepancies in the measurements when the valves are adjusted. Throw in a different set of feeler gauges and a different bloke or blokess doing the adjustment and there is plenty of opportunity for slight discrepancies ALL of which will mean that one cylinder will pump slightly differently than the other. That's the reason a big bell rings and a red light flashes whenever I hear that someone has been told that 'The TB's didn't need adjusting'. From there you have to ask what else hasn't been done or hasn't been done correctly.

Checking for yourself is sometimes easy. Just grab a 5mm Allen key and try turning both of the air bleeds on the TB's. If they are both open then you've been fed a pup. Both closed? This can be fine, its unusual but it is sometimes the case that there is no discrepancy in idle balance. One open? This is the norm and means at least its been set up by someone who knows. Both open and it means that someone has their head up their arse.

As for setting the valves "To the tight side of snug." Why would one do this? On most engines, (And the 8V is one of them.) as the seats and valves wear the valves recess and the clearances will close up. Better to err on the side of wide rather than tight! Who gives a flying fuck if you can hear them at idle? If you can hear them at 60kph your tappets have gone tits! Simple as that!

Ascertain if the job has been done correctly. If you have any doubts? Then my friends its time to learn to do it yourself. I know there are lots of people out there who simply want to ride and not twirl a spanner and it pains me that they are getting poor service because a Guzzi is about as simple as it gets mechanically and while some of the newer electronic stuff may require a new skill set and different tools it ISN'T ROCKET SCIENCE!

If Steve would like I can, when I get the chance, do a photo essay on a full service and tune up. I won't do videos because I haven't the time and I have to say I think that if you really suspect you need moving pictures then you shouldn't be puting a spanner to your own bike but if there is interest I'll do it again and in more detail for the Ghetto.

Pete

Pete,

Thanks for the response and the education. I already ordered the Carbtune to check the TB balance. If that fixes it, fine. If not, I'll do the valves. I, for one, would greatly appreciate the photo essay on a full service and tune up. (It's a shame so many of us can't rely on the dealer techs to service our bikes under warranty....when I called the other closer "world famous" dealer to have my first service done, the service manager asked me what a TB balance was!!!!)

Best,
TRw1 (Ted)

TRw1 wrote:

when I called the other closer "world famous" dealer to have my first service done, the service manager asked me what a TB balance was!!!!

  

   sigh.

I thought TB balance was something to do with measuring patients with consumption? (oh I slay me!)

Pete, a service walk through would be great!

TRw1 wrote:

Pete,

when I called the other closer "world famous" dealer to have my first service done, the service manager asked me what a TB balance was!!!!)

Best,
TRw1 (Ted)

He may refer to the procedure as "cylinder synchronization" as in the service manual, but you would still think he could recognize a synonymous term.

Pete Roper wrote:

If Steve would like I can, when I get the chance, do a photo essay on a full service and tune up. I won't do videos because I haven't the time and I have to say I think that if you really suspect you need moving pictures then you shouldn't be puting a spanner to your own bike but if there is interest I'll do it again and in more detail for the Ghetto.

Pete

Pete, I personally would love to see this added to this repository of knowledge. No so much for the blow by blow account of which way you turn the adjuster to reduce the valve clearance but more for tricks and tips for this specific motorcycle model. Obviously there are many on here who may indeed like the detail of how a full service is done ( I do though think a certain level of base mechanical competency should be assumed). I can certainly see how a tune up section would be a great reference for us all.

Steve, Would it not be possible to start  collecting some of the great stuff that exist on this forum into the Ex Libris section, just may help keep this great material all together and easily browseable (thats not a real word is it )

Look Guys, I'm more than happy to do it, its been done before but I can do it again and improve or re-edit it. I'm also going to be doing the swap from flats to rollers on my old shitheap soon so I'll do a photo essay on that too. Please be patient though as I'm on holiday at the moment and will be quite busy with *Real* work when I get home.

Been to some nice places but......

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Pete

Pete Roper wrote:

Look Guys, I'm more than happy to do it, its been done before but I can do it again and improve or re-edit it. I'm also going to be doing the swap from flats to rollers on my old shitheap soon so I'll do a photo essay on that too. Please be patient though as I'm on holiday at the moment and will be quite busy with *Real* work when I get home.

Been to some nice places but......

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Pete

Nice one Pete, looking forward to it.