Triumphrat

jedrake73

I have an 03 Bonnie, Staintune exhaust, de-snorkled, ai removed.

It was a CA model and had all the smog stuff and my idle wouldn't settle down so I pulled all the vac lines and capped off the rest of the ports and re-synched the carbs and the idle is a little better but still not as smooth as I think it should be. I like the keep my idle a little high so I have it set at about 1400rpm and it will set there for a second and then jump around about 50rpm up or down. Is this anount of varience normal? I ask because I used to have a Bonneville America that had a jumpy idle like this and when I pulled the smog stuff and capped the vac ports, the idle smoothed out perfectly. It would just sit exactly where I left it and not vary at all.

Jimi_X

My idle on my 2001 Bonnie (after warm-up) is rock solid at approx. 750rpm. I think you sort of answered your own question. Somewhere you have a vacuum leak. At 1400rpm the effect is less, try idling it down to 800 or 900 and see if it really becomes unstable. If it does, more than likely it is a leak. Check for cracks in the rubbers connecting your carbs to the intake.

Check your idle mixture adjustment. If it is to lean, it will be difficult to idle steady. If you have stock 40 pilots, usually the screws are set to approx. 2 1/2 turns out.

I usually put a small dab of auto tranny fliud, with a toothpick, inside the nipples just to make sure they are all airtight. Makes them slide on easier to.

badrufus

The idle should be pretty smooth. Once in awhile, if I've been riding on the highway and exit, I'll notice a little bit of higher rpm idling while I'm sitting at the exit ramp stop sign, then it smooths out (talking about going from 1000 rpm to 1100--nothing major--and I figure it's burning off excess gas from a more open throttle position on the highway). If the A/F mixture is correct, a Bonnie should run at a smooth idle. Mine sits on 1000 rpm with very little variation.

__________________
2005 T100

cdk80gs

If you have an air leak the easiest way to check I've found is to spray carb cleaner around the intake, some carb cleaners act like a boost and the revs will rise, others have the opposite effect and the revs will drop if theres a leak and the fumes get sucked in. Also 1400 is way too high for an idle, Id say around 900-1000rpm would be good. My needle fluctuates a little but the engine note sounds fine, I recon its just the tach not being as acurate as it could be.
Chris

__________________
'04 Bonnie Black, Mototwin exhausts, Dynojet needles, 120 mains, K&N filter, AI & snorkle removed,18T

jedrake73

Okay, good to know. The engine sounds fine, the needle just moves around a little, but I'll try turning the idle down and check more diligently for vaccuum leaks.

sweatmachine

50rpms? are you kidding me? who cares about 50 rpms?

if it's running well otherwise, and not acting lean, you probably do not have a vacuum leak.

like others have said, 1400 rpm idle is too high. I keep mine around 1000 rpms.

__________________
Who says being a tool is a bad thing? I have more use for my tools than I do for most people.


Click for a picture of my slightly modified Bonnie

Bhakti-rider

Mine (05 T100 with 904 kit & other stuff) idles perfectly at 400. I like a lower idle for the increased engine braking effect. Someone mentioned that that's too low for the alternator to put out sufficient current, but so what? I don't idle for any longer than a signal. And when I know it's going to be a long wait, I'll even shut it off.

__________________
James Dean drove fast. Albert Camus drove fast. Mario Andretti didn't drive fast enough.

RedBird

I've never let mine idle long enough to check.

__________________
Larry
2003 T-100 (790cc), NARK, NH Togas, 8100 rpm rev limiter, 158 main jets, 42 pilot jets (less than 1 turn out on pilot screws), stock needles--no shims. 13 A/F ratio from 1100 rpm to 4000 rpm; 12 A/F ratio from 4000 rpm to 6000 rpm; 13 A/F from 6000 rpm to 8100 rpm.:D
2007 Tiger 1050--White:D--SW-Motech crashbars, Skidmarx rear hugger/chain guard, Calsci +7 windscreen.

CAPTDON

When shes cold, she will slow down on idle. Warmed up- will hold @ 1000 rpm noproblem. I think I ahve a small leak in the caps. I twist & push & she runs better. Caps are 3 yrs old - time for new ones any way? Unless its all over the place - not to worry. After all they are Triumphs- not Hondas!! Got carbs- not EFI! If it dont stall or scream after warm up- its ok!! Will have to sync the carbs some day? Not so w/ EFI. Who cares??

__________________
CAPT D

mecscc

I like a high idle. Won't - again - go into what I consider very sound reasons for that. But 1400 is not automatically "too high" for some; any more than "800" is "too low." I don't have a tach, but a tach isn't particularly accurate at idle anyway.....Based on years of experience I would guess my idle is about 1200 plus or minus. I know it is nowhere near 800.

Just a thought.....

Monte

__________________
Monte

"The Old Ohio Preacher Man"