Author Topic: Lean running new b12 (Read 2976 times)

dickbarton · « **on:** September 26, 2005, 01:23:48 PM »

I tried to post a topic twice already, but here goes.

I'm just running in a new B12, done 400 miles.
It accelerates fine, but is hesitant and won't run smoothly on a constant throttle. Returned it to the dealer, who has ordered bigger pilot jets, because they think its running lean.
Has this happened to anyone else?

Dickbarton

B12Teuton · « **Reply #1 on:** September 26, 2005, 02:03:48 PM »

They do run a little lean out of the box, but shouldn't be that bad. They should start by adjusting the mixture screws before they start putting in jets assuming you still have the original exhaust system on it.

If it's really bad, don't let them charge you for the work! You presumably paid the shop a fee to "set up" the bike (feight and prep fee, or whatever they called it). If it doesn't run well, they already got paid!

dickbarton · « **Reply #2 on:** September 26, 2005, 02:57:53 PM »

No I'm not paying.
In fact, as I had to return it thrice, before I could get them to take me seriously, I told them to fix it or give me a refund.
Anyway, I hope it cures the problem so I can enjoy riding it. The handling is just beautiful for such a big bike. Much better than I remember during a test ride some years ago.

WEINERDOGBONE · « **Reply #3 on:** September 26, 2005, 09:40:43 PM »

It sounds like your about to get some free jetting. Good job. My B12 ran real crappy until I jetted it. Before I did the jets though, I drilled out the pilot screw covers and opened them up as suggested above. That little mod in itself helped quite a bit. You can also do that with the carbs on the bike. I used a Dremel w/a flexible shaft.

slo coach · « **Reply #4 on:** September 27, 2005, 06:56:46 AM »

I think the 1200 takes a long time to warm up,in fact mine takes about 5kms before i could get the choke off,then it ran like a dream.i got it to appear warmed up more quickly by changing to big pilots and it ran mint really soon after starting' but my theory now is that for regular 1200 bandit riding the throttle position ,as determined by the amount it is held open,is what i will call midrange throttle position and mid range is running on pilots more often than you imagine and the end result is a pain in the butt, running to rich situation which results in running to rich and fouling plugs,so my theory is that they may have got it to warm up quicker ,but they are barking up the wrong tree by putting bigger pilots in

cheers slo coach

dickbarton · « **Reply #5 on:** September 27, 2005, 04:23:06 PM »

Thanks, I seem to recall that the second time I returned the bike, the engineer said that he had adjusted the jets as much as he could, so presumably increasing jet size was the only option left. He said that Suzuki had reduced the pilot jets to size 15 from a previous 20. Thus representing a 25% decrease. I just hope it fixes the problem when they are increased again.
Whatever happens, I'll let you know.

slo coach · « **Reply #6 on:** September 27, 2005, 06:59:56 PM »

from 15 to 20 doesn't sound like they are overdoing it...i think that will be a go.

cheers slo coach

ray nielsen · « **Reply #7 on:** September 27, 2005, 11:22:20 PM »

My 2003 responded well to backing out the idle mixture screws a half turn.

Although it wasn't bad originally, the half turn sure made a difference. I can use the enrichener to start the bike and by the time I get the helmet buckles I can shut it off and drive away glitch free.

I did have to remove the carbs to get the mixture screw plugs out though and the hardest part of that job was reattaching the cables -- otherswise a fairly easy job.