Bonneville America Forums Forums Technical Forums Performance Mods Bike will not Idle below 1200

2003 America,150 mains, 42, stock needle 1 shim.TOR's
50,000 miles. Recently lost the cdi, replaced with Procom and thought it was the issue. Now running a stock CDI.
Here's the issues, the bike will not hold idle below 12-1300
Anything below that setting and after about 20 seconds the bike starts decreasing idle speed to the point of almost stalling.I've checked for any vacuum leaks with starter spray, replace the vacuum caps, checked the manifold rubbers. It's not a filter issue. Just had the valve clearances checked.Balanced the carbs as best I could with this issue.

Bike runs good in the upper ranges.
What say yea?

Have you checked the charging voltage?

Just a WAG thinking maybe the voltage was falling off the cliff below 1200 rpm and maybe you were losing yet another battery.

maybe a loose carb at the motor? Check the big rubbers for leaks too mike.

Kinda doubt it has anything to do with the valves being too tight... it would have symptoms at all RPM ranges. I'm thinking it's a simple carb issue..
I suppose you've already swapped out the cdi from the Speedy just to be sure thats not the problem.
I feel it is a float level or idle jet problem. If it were me, I'd swap the carbs between the bikes.

Has anybody adjusted the idle mixture screws recently? Could they be set too lean or too rich?

@ Chy, yes running the CDI from speedy. Same idle issue so that rules out the Procom. Swapping the carbs, not sure I want to go there just yet as the Speedy runs so well I hate to mess with it.
I do beleive it to be a single carb issue. While balancing the carbs last night the left one was pretty tuff to dial in. Float levels have not be checked.

@ Gregger, don't think it's a mixture problem. Last time these were touched was before my 5000 mile west coast trip. No carb issues at all then. Unless the dealer messed with them during valve check, not sure why they would have? I'll recheck them

Symptoms sound like it is loading up, but only at idle. Some bikes with pods want more air than what the throttle plate alone can provide. A potential fix is to drill a small air bleed hole (in your situation maybe 1mm) in the throttle plate.

Did the dealer just check the clearances or actually make some adjustments? Did this problem begin after the dealer service? If so, your bike doesn't like something they did.

@ Chy, you may be on to something with a clogged idle/pilot. I'll pull those and check tonight.

@ Oldroadie, I checked the charging system, all is good.

@ Gregger, the bike was not running great at the time and was way past due for valve check. I had recently installed a Procom CDI and assumed it was causing some issues. Currently running a stock CDI, So I can't say 100% it began after the valve check but it is getting worse. The dealer service was a week ago and I've only ridden the bike three days. I did check the mix screws and they are in the same setting I had them.

@ Lonzo, Thanks, I thought that was correct. The fuel level check will tell me if they are in spec.

If it shows the floats are off does anyone know if you have to pull the carbs to bring the floats into spec or can they be adjusted on the bike?

It can be done on the bike (I've done it), but it isn't easy. If you've never done it before it's best to pull the carbs.

Greg did it on the way to the NH Rally a couple years back. First by pulling the carbs under the Little Switzerland motorsickle lodge carport, then by just dropping the bowls down the mountain at the Mineral Museum. I know. I was there and it was HOT in the Museum parking lot.

Ok, I've checked the fuel levels in the bowls, spot on.
Pulled all the jets and checked for restrictions, cleaned and reassembled.
No vacuum leaks, no filter restrictions. Spark is good, charging properly. I cannot find the problem.
So back to the dealer this morning to have them recheck the valve clearances or locate the issue.
Kinda sux not knowing who's poking around on her.

Don't know, maybe yours does not need to have the plate drilled, perhaps a pilot screw adjustment alone will do it. You seem to have already ruled out many other potential causes. Just attempting to help you out.

I'll be most interested in learning the outcome.

Seafoam run like 4oz in a fresh tank of hitest. probably gum on some crucial part

You guys ready for this.

To recap:03 America 49,500 miles. Long Tor's, 150,42,stock needle with one shim. 2 1/4 turns out on the mix screws.
Just back from a 5000 mile ride where the bike ran flawlessy except for a toasted CDI.

I started having a few issues after installing a Procom CDI. The bike was way over due for valve check. That's one thing I just dont tackle.So I take her to the local big box dealer. They do the deed, I pick up the bike and with in hours the bike starting having issues idling below1200-1300. I'm thinking it that "damn Procom".
I swapped out the procom with a stock CDI. Boom same problem will not idle.I check everything I can think of,etc So back to the dealer to check her out.

Picked her up today and I asked to speak with the tech.
Me: so what did you find
Tech: well you know you got a lot of mods on her, AI gone, no air box, Free flowing pipes, etc etc. I had a fit with it and called Atlanta, etc. What I found was the mix screws were way off, 4 turns one one and 4.5 turns on the other. When I blipped the throttle black smoke just rolled. So I set the screws at 3 turns out, balance the carbs and she running good.
Me: say what! 4 turns out. Never, ever have the carbs been set at 4 turns out. I checked the mix screws before I brought her back. They were 2 1/4 turns. The bike has never smoked, period. Did you also do the valve check last week.
Tech: yes
Me: any chance you could have got one of the valves to tight.
Tech : NO,I always set them to speck.
Me: so you balanced the carbs you say.
Tech: yes
Me: So how were they ?
Tech: Just slightly off, but still in spec. But I have them dialed in.
Me: interesting, I just balanced the carbs before bringing her to you the second go round.
Tech: ...................crickets........

I paid the man fired her up, still unimpressed with the idle but it is better. Head out on a 75 mile run puzzled as hell trying to figure out the 4 turns on the mix screws. and he claims they are now at 3. I've never run the bike at 3. Anyway the bike runs pretty good, except it has a lot of pop,pop,pop, on decel which it did not have before. Hmmm says me, normally if the screws are not open enough, you get a lot of popping, or a leak somewhere. Pull in to a autoparts store and give her the once over. I found a cracked vac cap. When I took the bike in the caps were all new.
[image][/image]
here's what I found, the cap on the left is what was on the bike when I took her in. The one in the middle and the one on the right is what the dealer put on her. as you can see the one on the right is old garbage with a split. I was charged $6.83 for parts on the invoice. I replace the caps and head home. Still trying to put this together in my mind.
Get home jerk out a plug, looks good. Hmm. I gotta check those mix screws. WTH, left one is 2 3/4 turns out, right one is 1 turn out !!!!!!!!!!!!!! Idiot !

Dinqua mentioned the valve clearance possibly being too tight as the culprit earlier in this tread and I think he nailed it.

You decide what you think happened here. I'm pretty sure I know. I also know I was not told the facts by the tech.
i knew better than to take the bike to the dealer but you try to establish relationships and throw your local dealer a bone occasionally. Lesson learned, again!

I know a good tech in North Georgia, I'll be sure to ring his number the next time.

I don't get it. I mean, I get the part about it supposedly idling rich, but how does one reconcile what you said v. what the tech said?

I hear lots of good things about the tech at my local dealer but I still do my own stuff just because Im afraid to let anyone else touch it!

I think it's obvious, the tech lied on several occasions as evidenced by my findings. I have no reason not to state the facts.
The mix screw were never at 4 as he stated. he never set them to 3 as he stated.
Basically he had no clue, when I brought the bike back he started trying to tweak the carbs, never called me to see what jets were in the carbs as you can read in his notes I posted he "assumes there is a jet kit" etc.

My theory is most likely once he realized he had no clue he called corp, told them he had done a valve check and was told to recheck the clearances.Found one or more too tight as Diquna suggested and did not want to admit his mistake.
Then charged me for carb adjustment so he could get paid.

Just another great Triumph service department story.
$hitty job anyway you slice it.

Hows your bike now?

I hope it's okay and it's all over now, Mike.

Sucks bad when you try to give somebody a chance and they can't handle it. And charge you $$ for their ignorance, not to mention aggravation and extra time you had to devote to rechecking his work and
taking it back again.


I love how simple and easy these bikes are to work on, but I haven't tackled a valve adjustment, either. Thankfully I have an independent
shop near the house, that, though maybe not without fault, at least they
aren't over-run with more work than they can handle. The owner who knows his stuff, and one full-time tech and a good helper/intern. Stable, too, even this helper has been there a couple of years or more, as was the one before him... Mostly Japanese stuff and definitely no Harley work, but he does see a few modern Triumph come and go.

They do all my tire work, and my valve adjustments, and help me troubleshoot the few things that come along now and then. And they are my friends, whom I can say respect me as much as I them.

But we would all like to think the dealer mechanic would be the Holy Grail when we do resort to them...

I probably would not have paid them a dime if I knew they lied to me and didn't fess up.

I wish you knew the absolute truth because it's valuable information that we don't have access to now. That said, I'll bet you're 100% correct. The next time you want to do your valves let me know and I'll ride up with my homemade tools and we'll do it together :-)

You got it Ed!