Author Topic: Bandit spluttering, idling rough (Read 7155 times)

EdBundy · « **on:** March 08, 2005, 03:46:30 PM »

Hi all
Been reading all the posts a while back and there was some great info and tips - and now its all gone?! What happened?

Anywho, there was a thread about a problem with a bandit, it idled roughly and stalled when stopping. And now my bike is doing the same thing (should've paid more attention in class....) I've changed the spark plugs and they are functioning properly, so my guess is carbs. Any ideas, is this a common problem, what gives? It is pretty annoying.

Any insight will be appreciated.

PitterB4 · « **Reply #1 on:** March 08, 2005, 04:01:20 PM »

Hi Ed!

We... uh.... kinda lost all our posts. The dog ate them! Actually, we flipped a switch we shouldn't have and poof - they were all gone.

How'd the plugs look? Have you checked all the connections in the plug wires - it's common to have problems there and something easy to check.

Hopefully someone that remembers that specific post will chime in for ya.

echomadman · « **Reply #2 on:** March 09, 2005, 10:47:48 AM »

check your HT leads, if they're in bad shape the bike will not deliver enough juice to the plugs at low rpm, this is exacerbated in the damp/ when there's condensation on them in the mornings.

a guy on a bandit mailing list i'm on suggested this to restore them to betetr condition.

Quote

Do what i do, remove coils and ht leads, put them in an oven, to dry out
120deg for about half an hour. Pull rubber grommet up the ht lead and
insert into coil. Buy some spray on plastic coating from your local auto
dealer, spray onto the leads and coil. whilst wet push the grommets down
onto the coil and respray the coil and lead, guaranteed to work. works
for cars too,.

I replaced my leads (didnt do anything to the coils) and noticed an immediate improvement.
Worth a try before you go dicking around with the carbs. A few feet of HT cable shouldnt cost more than a fiver.

EdBundy · « **Reply #3 on:** March 11, 2005, 04:20:46 PM »

Thanks for the advice.... the plugs were a little sooted but nothing too serious. I suspect it's more from incomplete combustion than anything else, but that would also indicate bad firing I presume. Wouldn't leads take a while to develop a problem i.e. a gradual decline in performance? The performance on my bike basically went down in a few days, that's why I didn't suspect it (while a clogged carb will be immediate). But true, I'm not too keen on carb work as well.

Will try the leads thing next...

PitterB4 · « **Reply #4 on:** March 11, 2005, 04:50:27 PM »

The connections can become fragile and loosen with one bump. I didn't replace my leads yet. I just cut 1/2 off of each and reattached. It did the trick but I will prolly cut new ones.

echomadman · « **Reply #5 on:** March 12, 2005, 09:43:55 AM »

Mine went in a day, one day 4 cylinders, running great on the way to work, then when i started it to go home, one cylinder wasnt firing at low revs.
I tried trimming the lead back and reattaching, but it only stayed good for a few days. Its a cheap and easy fix to redo the leads.
Pop off the tank, unscrew the leads from the coils and caps, (number them or mark them with a bit of tape) cut fresh new cable to the same lengths and screw them in, and as the manual says, reassembly is the same process in reverse.

It made a huge difference

EdBundy · « **Reply #6 on:** April 04, 2005, 04:41:20 PM »

OK, so I'm very slow to reply, but I'm right busy.... anyway, replaced the HT leads no problem, but the problem persists. I've checked the spark and it seems strong enough even at idling speeds, so if it's not carbs I don't know what it can be. It's kind of frustrating, not being able to ride properly in traffic. On the highway she still screams like a banshee. Good times

ANy ideas before I rip the carbs open? Or at least check their synch?

Ciao

PitterB4 · « **Reply #7 on:** April 04, 2005, 04:50:24 PM »

Yeah - maybe try synching and see if that helps before you tear them totally apart.

Bandito · « **Reply #8 on:** April 13, 2005, 03:25:11 PM »

Had exactley the same problem on my bike. Started off with the cam tentioner that had to be replaced (Which you will hear if it is giving in) and then it ran fine for another month. Then same story...fine going to work but going home we were only pushing on 3 cylinders and it got worse. Immediatly parked it at the pro's. After they checked all the external things (Sparke plugs, carb balancing etc.) they opened her up. Found there was oil leaking to one of the spark plugs because of a pinched gasket at a screw hole. Then the bad news. One valve had a tiny chip in it and another had a hairline crack and carbs hasn't been cleaned in ages and needed some serious TLC (only baught bike 3 months ago). Seriously hope you don't have same problem. Can't wait to get her back tommorrow.

StrictlyStunt · « **Reply #9 on:** April 19, 2005, 12:08:00 AM »

I am having the exact same problem, my b400 idles just fine and runs ok, but seems like its running on bad plugs at low rpms and runs perfect at high rpms. I feel stupid asking but what are the HT leads? The plug wires or the wires that plug into the coils? I also discovered somthing, if I unplug the orange with white tracer wire that runs to the one coil the bike runs but as if it is only on 2 or 3 cylinders. If I unplug the same wire from the other coil, it immediately shuts off...does this mean that the first coil is shot?

kabatza · « **Reply #10 on:** June 14, 2005, 12:03:18 AM »

HT leads are the thichk cables going from the coils to the spark plugs. Your problem sounds like incorrect valve clearances or valve problem to me. the first more likely!

My bandit is even worse though because it only runs in cylinders #1 and #2.
#3 and #4 will not fire no matter what I've tried. I have spark, compression and fuel in all 4 cylinders. It starts and idles but the exhausts #3 and #4 are cold. reving the engine makes no difference, but when I try to ride it, it pulls like a 50cc scooter. I suspect the ignition coils but when tested they give primary 3.2 and secondary 33k is it possible that one output of each coil works and the other is not? i remember this happening in a hot day riding on the motorway last summer and I thought It had it, but when stoped and swiched the engine off ant back on it dissaperaed. It was a hot day last friday, and it happened again, but now its pernenant. It has to be the coils....what do you guys think?
Oh yeah I have chcked and cleaned the carbs