Balancing Throttle/ Intake Ports

[lad]

Something is off. Valve adjust maybe. Air leak maybe.
Do you have GuzziDiag?

i do. for what?

i sprayed the rubber boots either side of the throttle bodies with starter fluid abs there was no perceptible change, in regards to an air leak

[lad]

i did valves. left was at 15/22 (in/out) and right was 20/23.

i set them back to 10/15 as per the manual. a know people say 15/20 but i’ll go back to stock and work from there.

[lad]

Not sure if anyone’s left but here’s an update,

after valves i decided to re-balance throttles. I checked my baseline was still .150 and then went with guzziDiag to set tps by degree, i went with 3.21, it was that or 3.03, nothing read in between, this translated to .475 on the multimeter.

from there, the balancing procedure went according to a various PDF plans, it was idling around 1100 with a half turn of the air bleeds.

After a ride, it was still backfiring, when downshifting mainly or rolling off throttle.

i had messed with the trimm a bit also, it’s reading 67 on Diag.

when i got back i was idling around 13/1400. is it meant to be done with a warm engine? probably.

i might try reset the trimm to centre, but i’ve to read up more on it, or i’ll try find someone with a gas analyser.

i might redo the balance when warm, but i was happy with working off throttle degree. that said, maybe it was because of valves and i should go back to the .375 mv. too many variables

[Tom H]

Not sure why your getting the backfire?? Loose header pipes/bad gasket, loose header to crossover or muffler?

The idle. You can try to adjust the bleed screws to bring the idle down. If that fails, you "could" back out the RH TB idle screw just a hair or two to get the idle down.

Tom

[lad]

Not sure why your getting the backfire?? Loose header pipes/bad gasket, loose header to crossover or muffler?

The idle. You can try to adjust the bleed screws to bring the idle down. If that fails, you "could" back out the RH TB idle screw just a hair or two to get the idle down.

Tom

would loose headers do it? and which gasket? i have a rattley exhaust at 2k rpm but can’t locate it by hand.

wouldn’t my bodies be out of balance if i just adjusted 1 ? i’ll knock the airs in a touch and see

cheers

[lad]

is this the gasket?

[lad]

i get ya, this rusty looking fellow wedged in here? 

There is a gasket in the head where the header pipe goes. I **think** that is the one Tom was referring to.

John Henry

[Tom H]

John, yes, the one where the header goes into the head.

Lad, The picture shows the cross over and is where a leak could be as well as where the muffler connects to the cross over. Also check the nuts that hold the header to the head. They sometimes come loose. A firm pull on the wrench is all that is needed, you just want them good and snug.

If you turn the RH TB idle screw out about 1/2 turn or less, it "probably" won't matter to the running balance.

Glad your making headway. Your bike is one where Guzzi introduced new parts and "I feel" there is not a definite answer to setting up the voltage/ throttle angle for the LH TB in a book. If you have it running well and getting decent mileage, let it be. OR...take some time and try the other options for the LH TB. You have experience now. IT will take less time to make the changes and go back if needed.

Tom

[Tom H]

i get ya, this rusty looking fellow wedged in here? 

There is the outer clamp, a sleeve/spacer and then the gasket. IF you decide to dig in there, it may look like there is not a gasket in there. They sometimes look like part of the casting.

Tom

[Wayne Orwig]

after valves i decided to re-balance throttles. I checked my baseline was still .150 and then went with guzziDiag to set tps by degree, i went with 3.21, it was that or 3.03, nothing read in between, this translated to .475 on the multimeter.

I thought you had a California 1100i, which has the P8 computer. On that you set baseline (butterfly closed) to 150mv, then crank the idle stop open to 385mv, or about 2.1 degrees on GuzziDiag.

[Wayne Orwig]

i get ya, this rusty looking fellow wedged in here? 

The rusty bit is the metal 'plate' that presses the exhaust pipe into the head. The actual exhaust gasket is hidden behind the pipe and pressed into the head.
If it is a leak at the head, you typically hear the air leaking out.

It there is an aftermarket crossover, those often leak. There is no gasket down there. But I have fixed some by using aluminum shim (beer can) wrapped around between the inner and outer pipes.

[lad]

I thought you had a California 1100i, which has the P8 computer. On that you set baseline (butterfly closed) to 150mv, then crank the idle stop open to 385mv, or about 2.1 degrees on GuzziDiag.

i do, but in a grey area with a PF3C TPS, i have been at the .385 mv and the .525 and neither stopped backfire, i went with 3.2 throttle degree after valves, just out of curiosity, as it was recommended in a tutorial, but i might swap back to the 2.1 now and see, i’ll play around a bit with that and the CO trim and then look into a leak-down test maybe.

Actually here’s some sparks pics if anyone spots anything ...



left is left etc. these only have about 40km on them, but were pre-valve adjustment.

Getting there anyway, bit by bit, thanks again