A simple method for Idle speed adjustment?

[Dan M]

Grazie

[docc]

There's no reason to say this. What you say is wrong. Turning the idle screws, or in other words, adjusting the idle revs to one's personal gusto, is exactly the same as pulling in the idle lever, just in the opposite direction. It has nothing to do with balance, synchronousity or TPS base settings.

 

It may be not a good idea to have the idle set to too low revs, but again, this is a different thing than just turning the stop screws out or in.

 

Hubert

 

Well, Hubert, that depends. Some of these bikes have had their right idle stop defeated, in which case turning it will do nothing at all. Some procedures have used both the left and the right to set the throttle body balance at idle, in which case truning the right screw would affect the balance at idle due to play in the linkage rod.

 

I would agree with you that once the TPS baseline is set at the correct idle rpm (not the tach indicated rpm ), and the throttle body balance is set, the idle can be changed to suit the rider or the conditions. One must still be aware of how the idle stops have been used in the balance procedure as this is not always the same and it is very common that the right side screw is completely backed out.

[luhbo]

... in which case truning the right screw would affect the balance at idle due to play in the linkage rod...

 

.... be aware of how the idle stops have been used in the balance procedure as this is not always the same ....

 

If the linkage play affects the balance (and the complete linkage itself is still in good and usable condition) then the synchronisation was badly done. I say this not as a fact, just as an advice. If one has problems with how his engine behaves, then always and only in driving situations when the flaps are off the stops. Not at idle and not at WOT. If one uses the idle stops during the balance procedure in order to get correct readings on his clocks or mercury sticks then he does himself not a favour.

 

Hubert

[docc]

I found this to be true as well. There is not an advantage to using both idle stops to have any synchronization. It is, in fact, better to back the right screw fully out and use only the left and the tension in the linkage rod to make balance at idle. (I've done it both ways).

 

There remains the debate about 1) what is "idle" (since the tachometer might be 200-300 rpm high, or even 500 over; and 2) should idle be balanced with the air bypass? ( I think not, but, others disagree).

 

I suppose, if one wanted to just crank the idle speed up, and not mess around with "tuning", it would be easiest done with the left screw as it is the easiest to get to.

[luhbo]

....

There remains the debate about 1) what is "idle" (since the tachometer might be 200-300 rpm high, or even 500 over; and 2) should idle be balanced with the air bypass? ....

 

1) I for myself define idle as a static running situation. Your background are big V8s, my background are old VW beetles and TWN split piston engines, so we both tend to define idle as well below 1000 But that's not relevant. The relevant word here is "static", no load.

 

2) I define the air bypass screws as an instrument to compensate the always existent flap and bore tolerances as well as other deviations caused by wear for instance. That's why the Guzzi manual says you should balance the flaps (adjusting linkage length) with bypass screws closed, at 2500 min-1 or higher. The idea behind it is that at higher revs and corresponding flap openings the influence of diameter, roundness and wear deviations is already very small. Besides that this is the region where the transition from idle to load and most of the "cruising" takes place.

 

So for me the easiest way to adjust the flaps is: stick to the Guzzi manual. I bet in nearly 100% of all cases this will give usable results. If one wants more he should know what he does. The forum will not be able to give him usable advice in this case.

 

Hubert

[docc]

Hi, Hubert! Thank you for your conversation!

 

I find my shop manual lacking in several usable components. Chiefly, I cannot measure "degrees of opening" and need the conversion tables for mV to set the TPS. There are other confusions in the manual procedure which is very brief.

 

Reviewing the "Forum Procedure", I can't say I follow this procedure entirely either.

 

I'm thinking the "tuning" is more like playing a musical instrument than just following a given "procedure." I think, Hubert, you and I could make some beautiful *music* together!

[v11cafe]

 

I'm thinking the "tuning" is more like playing a musical instrument than just following a given "procedure."....

True, but there is a given method..like in music ppl learn the right way to play

but at the end comes out the personal way and interpretation.

 

I think the reply to the post question is yes....maybe....no

depends on how much you have played with the adjustment procedure.

[docc]

True, but there is a given method..like in music ppl learn the right way to play

but at the end comes out the personal way and interpretation.

 

I think the reply to the post question is yes....maybe....no

depends on how much you have played with the adjustment procedure.

 

That is very well put. I may have made it sound like I tune "by ear" or some such. Not so.

 

In the beginning, the bike was "tuned" by the selling dealer. Their approach was, "it starts, it runs, don't mess with it."

 

I then began to use the compendium of procedures in Guzziology using my shop manual for reference; Followed then by the JeffinOhio system; finally appended by the (pinned) forum discussion.

 

After about ten tune-ups, I've found the parameters get closer and closer and she runs better and better. Over the years, I've sen the "tune-up" solve some horrendous impressions of terminal mechanical and electrical failure.

 

It is notable, though, that the answer to "setting the idle" becomes: perform a full tune up including valve adjustment.

 

Yet, after you've got this accomplished, you can turn the little screw.