Bandit Alley

MODEL SPECIFIC => SUZUKI BANDIT 250 & 400 => Topic started by: jpax on May 09, 2005, 03:52:59 PM

Title: Somethings wrong
Post by: jpax on May 09, 2005, 03:52:59 PM
I am having a  little trouble with my bike. I parked it yesterday after a 15 minute ride and when i came back about an hour later i noticed it would start that easy. When i did get it started i noticed i had very little power and it was horrible idle. (500 rpm) So i rode it home and when i got there i noticed that the two headers in the middle were not very hot at all. I was able to grab them both while the others i couldn't touch. So i figured that two of my cylinders aren't running. I checked the plugs in the middle and they were black and wet.  But they still sparked when i turned the engine over. I cleaned them and put them back in.
Just wondering if i could get some advice on what to do.
Title: Somethings wrong
Post by: Red01 on May 09, 2005, 09:24:38 PM
Wet with what? Fuel, oil, coolant?
Title: Somethings wrong
Post by: jpax on May 09, 2005, 09:38:52 PM
Wet with fuel
Title: Somethings wrong
Post by: Red01 on May 09, 2005, 11:55:19 PM
If it was running fine, then went bad, is wet with fuel, but sparks good after you pulled the plugs, sounds like you may have lost a good connection and it was made good again after you disconnected and reconnected the plug wires.

BTW - How did the spark on 2 & 3 compare to 1 & 4? If they aren't pretty close to the same, or 2 & 3 are still "dead" after you put the plugs back you could have a coil or black box issue. You can troubleshoot this by swapping the coils and if the problem moves with the coils, you have a bad coil. If the problem doesn't move, then the problem is upstream of the coils, either in wiring or the black box.
Title: Somethings wrong
Post by: jpax on May 11, 2005, 03:06:39 AM
ok all my plugs where black and wet so i am assuming that i am running too rich. i changed all the plugs and it seems that they are all sparking about the same. tomorrow i am going to switch the coils over and test that. my carbs where just cleaned and synced 2 weeks ago. so is there anything else i could look at
Title: Somethings wrong
Post by: Red01 on May 11, 2005, 07:04:38 PM
Got a clean air filter?
Title: Somethings wrong
Post by: jpax on May 12, 2005, 01:53:05 AM
i am not to sure but how could that only affect two cylinders and not all four.
Title: Somethings wrong
Post by: Red01 on May 12, 2005, 02:23:48 AM
It wouldn't, but it could account for all four plugs getting wet because a dirty filter makes it run richer.
Title: Somethings wrong
Post by: kabatza on June 14, 2005, 12:06:41 AM
Very similar problem mate!

My bandit 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 Hi Doc, I would like to ask a question about my little bandit 400. It only runs on 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 think?
Thanks! Oh yeah I have chcked and cleaned the carbs and the vacum is spot on. also valve clearances within specs.
Title: Somethings wrong
Post by: Red01 on June 14, 2005, 01:11:57 AM
Quote from: "kabatza"
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?


Possible, but unlikely. To be sure, swap the leads between 1 & 4 and 2 & 3. If the problem follows, it's the coils or the leads. If the problem stays, it's something else.
Title: Somethings wrong
Post by: kabatza on June 16, 2005, 10:47:17 PM
I did swap the cables! now it starts and runs a bit better, and then it just dies and does not start again. Then starts again and then stops. Its mad! I always have spark at the spark plugs though. is it possible to have spark but the coils to be bad somehow?
Title: Somethings wrong
Post by: PitterB4 on June 16, 2005, 10:55:46 PM
:duh:

If the CDI/blackbox/cpu/gdi... whatever you want to call it goes, one of the symptoms can be having good spark but not at the right time and therefore the bike will act funky.  

Discaimer - I'm a mechanical idiot.  Please don't put a lot of stock in any mechanical advice I give just because I have the ability to correct gsxr400racer's spelling.   :stickpoke:
Title: Somethings wrong
Post by: gsxr400 racer on June 16, 2005, 11:43:12 PM
Hey Rob  :monkeymoon:  If it isnt RED it you I figure i take the time to type who cares about the spelling could just be a looker and not a typer! But youd all miss my noodleage in the end! :thanks:  :beers:  :duh:
Title: Somethings wrong
Post by: PitterB4 on June 17, 2005, 08:59:38 AM
Quote from: "gsxr400 racer"
Hey Rob  :monkeymoon:  If it isnt RED it you I figure i take the time to type who cares about the spelling could just be a looker and not a typer! But youd all miss my noodleage in the end! :thanks:  :beers:  :duh:


Aw man - I was gonna use it as my new sig!  LOL.  Just teasin' ya Jay.
Title: Somethings wrong
Post by: gsxr400 racer on June 17, 2005, 09:07:01 AM
I know bro! :lol:or be :lol: at!
Title: Somethings wrong
Post by: gsxr400 racer on June 17, 2005, 09:17:25 AM
back to the topic , First thing is change the plugs ! second when you cleaned your carbs did the floats just fall out? (they should always go in snugg) third coils break down when they are hot to me it sounds like a coil problem or your float orings (if these o-rings are bad your carbs (like a toilet running have no way to shut the fuel off) you need to find someone with a coil load tester. ive seen a fancy one made outta peice of wood and 2 nails i think in the back of a clymer manual once but have never got around to making my own verey helpfull and cheap what it takes is a battery some wire and the 2 nails to make the gap for the load .  as the spark jumps the coil heats up and instead of a constint zaaaaaaaaap you get zaaaaaaaap,-zap-zap-zzzzzzzap !
(well i tried to spell all that right) :beers:
Title: Somethings wrong
Post by: kabatza on June 17, 2005, 04:38:37 PM
thanks for the reply. Carbs are in perfect condition and the float o-rings too! Problem does get worse when bike warms up! when warm is nearly impossible to start it. so pobably the coils! I'll try and find a replacement pair!
Title: Somethings wrong
Post by: kabatza on June 19, 2005, 09:01:51 PM
Strange thing!!  I was reading the posts and i came across the info of the coils that fire each cylinder. left= #1 and #4, right= #2 and #3.  I'sure I've been running mine with left= #1 and #3, right= #2 and #4 for about a year.  As it started running on 2 cylinders recently, I decided to swap them and although it took ages initialy to start, now it runs again in all 4 cylinders. very strange!