Real head scratcher

Roadster Reggie · Aug 17, 2019

My 2013 Roadster ran great since I got it last year, 36,000 miles on it now.
I took the cam cover off to do a valve clearance check a few months ago, had the throttles off too, clearances all good so I put everything back.

It ran ok but a little lumpy, and people on Facebook recommended TuneECU, so I got it and found throttles were a little out of sync (670, 650, 620 front to rear), so I synchronised them as best I could (640, 640, 630).

This made it run worse, in fact it barely keeps going unless I give it a feather of throttle.
I also did an ISCV reset, all was as per specification there, and reset adaptives. Nothing made a difference.

However... if I deliberately unsync the throttles, to say 680, 610, 610, it runs pretty strong and smooth.
But it does have a tendency to drop revs and die when I'm coming to a stop sign or something where i close the throttle and pull the clutch, so it's not right.

Anyone heard of this? Anything else I can try?

Or does a Rocket run better out of sync..

Claviger · Aug 17, 2019

So to help you out a few pieces of info please:

What exhaust?
What intake?
O2 sensor enabled or disabled?
What is your TPS voltage both low and high values during ISCV reset?

I've had similar experience with the balancing. In my case, once I had them synced, like you, it idled really bad. I ended up desyncing them and resyncing them twice more, on the third effort it idled smoothly and ran better than before I started.

Roadster Reggie · Aug 17, 2019

Everything is stock, the O2 enabled, 0.59v and 0.72v during the ISCV reset

So you think I should keep plugging away, and it will come right at some stage, kind of by accident?

R3Tex · Aug 17, 2019

Stupid question maybe, but did you check all of the vacuum hoses on the throttle body to make sure they were firmly in place?

Navigator · Aug 17, 2019

Not a stupid question Tex. I had that issue with a VStrom and it was driving me nuts. A guy on the Strom forum suggested the same and that was it. I felt a bit foolish for not having immediately checked it.

scot in exile · Aug 17, 2019

Seems like a vacuum line or something has been disturbed during the valve check, re-trace your steps checking everything also double check the map sensor.

Roadster Reggie · Aug 17, 2019

Thanks guys. I just checked the hoses and they look ok

also the throttles all read like they are pulling vacuum ok, when i turn the screw, one cylinder vacuum goes down and the other goes up, if i turn the screw the opposite way, the reverse happens.
If i rev it up, the vacuum changes sharply to like 400 so it seems to be reading ok and no leaks.. I don't get it

Tripps · Aug 17, 2019

Some here have found setting the tps a little higher helps idle, .63-.64 even, plus .12

Claviger · Aug 17, 2019

As Tripps mentions, try setting to .63 or .64, I know it's against the manual's directive, but we know from experience it helps, it seems more so on late roadsters than other versions.

Rebalance them once set to .63 or .64.

Roadster Reggie · Aug 23, 2019

Claviger said:
As Tripps mentions, try setting to .63 or .64, I know it's against the manual's directive, but we know from experience it helps, it seems more so on late roadsters than other versions.

Rebalance them once set to .63 or .64.

Throttles in balance (she runs/sounds like a thumper, and very shaky/vibratory);

Set TPS at 0.63/0.64v (flickering between);

Then the second voltage - this is about the highest I can get, any further and the little nut is starting to come off the idle stepper motor's arm;

Then the bike ran the same as before, sounds like a thumper!

So I switched the bike off, turned both balance screws anticlockwise by 1 turn each, set the TPS to;

and the second voltage was then 0.77v;

So I turned the nut inwards on the stepper arm until 0.72v;

Then started the bike, and initially it still ran crap, but after a few seconds it magically started idling smooth and strong again!!
But throttles are out of balance.....

Real head scratcher

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