Smooth is hiding from me

Nah. They're just extra earths I think.

Over last week:
- fitted two layers of shrinkwrap over length of plug leads
- checked and adjusted valve clearances - found shop had set at 6/8 during service so brought back to 4/6. Rebalanced etc
- ordered Ago megaphone. Should be hear next week. Beetle map procured to suit.
- Mario lent me an old Termi he had in the cupboard to try. Loaded the Ago map on basis its probably closer match than the oem exhaust based map. (?).
- Baffle out initially - good god it was unbearably loud (for my baby ears). Sound was fantastic but just couldn't live with that. Baffle in - perfect.
- stutter still there ( sadface)
- back to one of Beetle's earlier questions - does seem a eng temp related - really noticeable after I go back to 3k after giving it some. Something opening up / warping ? Rechecked all inlet and exhaust joints. All ok.
- CPS is next. Maybe temp related clearance changes there at work. Checked resistances. hmm. Have ordered one. Luckily its standard Fiat part so don't have to pay mad Guzzi prices.

Will get your coils back to you shortly Pete.

Ago on after some pain but just could not get cat to fit, so running without. Probably but too free breathing as a result but am trying to work with it. Balanced up OK.

CPS changed without any effect

Reitted wideband kit - neatly this time and mounted gauge under dash. (Looks like dash of hot ute now. Just need some blue neons somewhere). Really helpful insight into trouble spot - flicks into lean in narrow band around 3k rpm / low tps. Fiddling main fuel without much effect. On last run tweaked fuel phase with good result.

Will tweak some more...

Hello

Whaou ! Wow! , big search .
I am impressed to see everything you've tried to do on the GRiSO.
And I would be distraught after all that work.
A Stelvio had a similar problem, cut between 2000 rpm and 3000 rpm.
it was decided stupidly to change the air filter that had yet less than 10 000km.
Very simply I hardly dare ask the stupid question.
Did you try a new air filter ?.

I do not think this will solve your problem, but it would be a shame to have missed such a basic thing.
You have tried almost everything.
This will be hard to do more.
I will follow your post with great interest.

Bonjour Jean
Good thinking but yes air filter has been changed during the whole sequence.
Currently playing with fuelling again. Latest is to try some additional fuel on right cylinder as per Beetle suggestion. First go didn't produce as much effect as the phase adjustment. Will be playing some more over weekend.
Going for longest thread...
Conor

Some good progress. Logging as well as keeping an eye on my dash mounted AFR gauge has proved fruitful.

(For those interested have taken Beetle's Ago map and thrown a titch more fuel (5%, yes I know, more than a titch...) in a very small band (2500-3500 rpm, 5.8-9tps) and 2% in surrounding main fuel table cells. ) very good results, mabe a little more than really needed but AFR is in better space and stumbles gone. V small zone around 3100 stll lifts up into mid 14 afr so have adjusted that zone up a little in my latest - currently rev 12 !) .. Might be able to back it down a bit and use plugs to guide balance of delta left vs right if need be, but its a much happier beast and haven't had to disturb the economy in the > 3500 range where afr's are fine.).

Magic

Phew.

I can't pretend to understand all that but am prepared to discuss over beer soon. Or even a ride. At beach shack at present but home in day or two.

Still strikes me as weird. These engines are made to a pretty rigorous standard. I'm just surprised that there can be such a huge dichotomy in performance. I suspect there may be an underlying cause of some sort but I have no idea what. That's why I'm keeping quiet!

Pete

GUZ21 wrote:

I can't pretend to understand all that but am prepared to discuss over beer soon. Or even a ride. At beach shack at present but home in day or two.

Did you say beer?
Friday lunch?

GUZ21 wrote:

I can't pretend to understand all that but am prepared to discuss over beer soon. Or even a ride. At beach shack at present but home in day or two.

Over East at the moment through to Saturday and as usual I'm no good for Friday rides/lunches/beers ... I'll still be pushing pens around my desk...you go right ahead though....

Diablo Loco wrote:

GUZ21 wrote:

I can't pretend to understand all that but am prepared to discuss over beer soon. Or even a ride. At beach shack at present but home in day or two.

Did you say beer?
Friday lunch?

Chidlow Tavern? High Noon?

Si! Chidlow Tavern. Black beer. High Noon.