TPS adjust/TB balance/air bleed screws

[raz]

I thought we could do better.

Maybe we still can, but the instructions will lose their simplicity.

You're not giving up are you? When we sort out what is causing some bikes not responding well to the pinned method, chances are it's not even very complicated. Maybe a couple of extra checks in the procedure here and there, like "if TPS at this point is bla bla then set bleeders to one turn instead of a half and go back to step x" or "if you have this and that number on your ECU label, use this TPS idle voltage".

 

This discussion will go on with varying intensity (it's very weather depending, for instance) and now and then we'll make some progress

[Ryland3210]

:!:

 

Wouldn't it be nice if the balance could be done at 3K RPM with the engine loaded as if the bike were cruising. The equivalent might be balancing unloaded at some higher RPM, but as Skeeve indicates, his mercury bounces around too much for that.

 

On the other hand, it takes such a tiny bit more throttle to go 3,000 versus just off idle with no load, I suspect it makes little difference whether it's done at 1,800 or off idle or 3,000.

 

For the true perfectionist, here's a procedure to consider.

Attach a voltmeter to the TPS.

Measure the voltage with butterfly closed and make note of it.

Monitor the TPS while cruising on the road at the target speed.

Run the bike on a dyno with the throttle held at the measured TPS voltage with the load set to control RPM corresponding to the target speed.

Balance the throttles.

 

To make things even more interesting, monitor the F/A ratio and adjust the TPS to achieve the desired ratio at the same RPM and load as above. As power output varies, the physical throttle position may have to be varied to maintain the RPM and load constant, making this an iterative procedure.

Shut the bike down.

Measure the TPS voltage with the butterfly closed and compare to the initial reading. This will tell you how much offset was required to obtain the desired F/A ratio.

 

If not too far from 150 mv, you could consider leaving it where it is. If it is far from 150 mv, consider having the ECU remapped.

 

If I had access to a dyno, I'd do it just to learn something and see what difference it would make, if any.

[dlaing]

Interesting ideas.

I was considering putting my stock air box lid and stock mufflers back, hooking up the WBO2 sensor and log the results at a few different TPS settings.

Not sure if it would produce anything interesting. For the most part simply a change of mixture, but the timing does some odd things.

Looking for large changes in the columns will provide a clue as to where we might see lean and rich increases.

Here is the ignition map

http://img123.imageshack.us/my.php?image=tb9ignitionkb5.gif

and the fuel map

http://img222.imageshack.us/img222/154/lemansmap3mj.gif

More importantly, I could also try the Ti map, which has unclear TPS setttings.

[dlaing]

You're not giving up are you?

No way!

I just got my O2 sensor in the mail, so lots of fun may be about to start, if this sensor works.