Bandit Alley
MODEL SPECIFIC => SUZUKI BANDIT 250 & 400 => Topic started by: Sean on July 26, 2012, 08:09:51 PM
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Hi. I recently rejected my carbs with the factory pro config 30 kit. I am running with an aftermarket exhaust and kn pods. I wanted to ask for advice on how to get this thing tuned properly from others who have similar set ups (particularly TJS and gsxr400 if I remember properly). My biggest issue is super richness and stalling when attempting idle (or anything below 4k). I'm on the 117m jet with the needles one clip from the top. If you has any thoughts let me know. I creep on this site like every 20 min so responses will be prompt. Thanks for the help. Oh and petcock is good. On prime with an inline valve (till the offseason).
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One detail I forgot to mention is that when reved (with pods off) a fine mist of gas sprays out of the carbs. Not sure if this is important.
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That config 30 kit has been around forever and the directions are pretty spot-on.
You sure all was good with your carbs before you dropped it in? All the rubber bits? Floats at the right height (this would affect your rich idle the most along with everything else)? Some fuel coming out of the carb throats with no filters is normal when revving without a filter. You're seeing the reversion wave push fuel back out.
You could contact factory pro directly as well as they're very good with customer service.
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For me low end richness was caused by worn needle jets...
http://forums.banditalley.net/index.php?topic=11225.0 (http://forums.banditalley.net/index.php?topic=11225.0)
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I forgot about your Mike, those still take the cake for the worst ever!
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Just a question, is the 117 main what came with your FP 3.0 kit?
I've go the 1.0 and it came with 95's and 92.5's. I ended up using the 92.5's after a spark plug check.
Did you do a plug check?
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To be honest I'm not sure how these carbs were before I started jetting them because yet were ordered off of eBay to replace a really leaky set. The original leaky set was all ghetto rigged with goopy stuff sealing the cracked orings between the carbs. I should check the needle jets. I have thought about doing so before but opted to just try and look with a dental mirror. How do I remove the needle jet?
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Yeah I did a plug check and have a decent spark. Trimmed back the wire and reattached the spark plug boot. Plugs are definitely dark and smell gassy. It's so rich that when I pull the entire carb rack there is noticeable gas on the intake (between carb and engine).
My kit came with 120 and 117 jets.
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If your plugs are dark and you are using the 117's that came with the kit then my vote is that you need a carb rebuild with new o-rings/float valves.
I ordered some kits online for a katana 600 that used the same carbs....
About the only think I'd check before doing that is the # of turns out the fuel mixture screws are....and compare with the little sheet FP sent with the jet kit.
I'm all stock in my case except for a K&N...and they recommended 2.25 turns out...
(although I just got a Yosh header and I'm going to make a custom mid pipe and slap a tyga stainless oval on it soon...so I'll be upping the mains soon too...I'm just leaving the airbox alone because I just don't want to deal with pods)
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My float valves are good. I replaced them with ones from a spare set of carbs the orings around the part that houses the float valve is sealing. I'm tempted to (I know it would be messy) take off the bowls and inspect floats and seals.
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I pulled the emulsion tubes and they were very gummed up. I'm not sure if this would cause my problems but they're clean now and I also replaced the float o rings and checked the float needle valve for wear and theyre good too. Gunna test it later.
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What country is your bike from? The factorypro kits are setup for US bikes. Canadian and euro bikes have emo tubes that are a size larger then the US tubes. My bike ran much better with the factorypro kit when I switched to the US sized emo tubes.
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Im pretty sure the bike is a us model. And the tubes from the new rack of carbs turned out to the same size. I had no clue there was a differance. Thanks for the heads up though.
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Tried the newly gone over carbs today and it idles very nicely now but produces some white exhaust smoke. Once I turn the bike off the exhaust trickled a small stream of the same white smoke contined for like 40 seconds. This is a new symptom that didn't happen before I adjusted the carbs. Is this a sign of running lean? I did set the floats lean because I was previously super rich.
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Can you video the bike from start up? Be sure to show the rpm guage on idle and blipping the throttle after warm up
Where do you live? Humid? Cool? High or low altitude?
To Do list:
* Factory Pro website for tech "How To..."
* Try setting your floats back to stock
* turn air jet to 3 turns out
* Raise needle by lowering your clip
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Cool. Ok I'll get the video up. Prob tomorrow. She idles now but surges and returns idle irregularly on her own and sometimes dies when coming to an idle after a run (like at a stop sign). I live in Pittsburgh Pennsylvania and its been hot and humid. I have iffy compression on one cylinder (we suspect a bad piston ring did the whole squirt oil in and retest thing). I have a parts bike potentially lined up and plan on boring out this engine in the off season. Right now my floats are at 15mm with the 117 jet and the needle clip is on the top most notch this is the least rich I've been able to get her to run. I have been toying with the thought of unpluging the pilot screw tamper plug and try adjusting that in my next carb sync. Bad idea?
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Yes, remove plug! Adjust screw to three turns out. That should help some idle issues. Then using a really small screw driver you should be able to leave the carbs on and adjust at 1/4 turn increments. Don't get confused in what direction you turn. It can be confusing after just looking at the bottom of the carbs on a table, then trying to turn them on the bike and switching from each side of the bike to reach the carbs.
I will try to see what size jet I am using tomorrow afternoon. I would think raising your needle would help. Air screw, slow jet (probably stock), and needle are working at lower rpms before getting on the main jet (117).
Make this a favorite:
http://www.factorypro.com/
pruduct support, motorcycle tuning tech, CV Carb tuning (on left side of page), High RPM engines (in red letters)
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Now go back to CV Tuning. Scroll down to The "Tuning" section. You will find the Bandit 400. Make this a favorite.
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Oh wow the bit on tuning, further down the page where it mentions the pilot screw, seems to to pretty much hit the nail on the head "lean surging" seems to be my issue. Before we do anything I'll take a video and post it. Thanks for all of the advice so far!!!!
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Ok video will be up tomorrow. I left my camera at my girlfriends mothers house (where I'm keeping the bike) and I went back to my apartment without it. I think youre spot on about setting the floats back to stock because she didn't want to start at first I had to put her on charge and then on the second round of tries I got her to start, this is the first time this problem presented. This is also the first time she started cold with her current float height. (1mm above stock 15.6mm). Just thought I'd keep you updated. Is it ok to set the floats down and pull the pilot screw plugs ASAP like right after I get the video up or should I hold off until you can analyze the video?
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Go for taken the plugs out! You are on the right path. Follow the factory pro info and you will be fine. Trial and error...patience.
I am running the 117 main jet also.
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Videos
Initial start
http://www.youtube.com/watch?v=BrTCuO-vslQ&feature=youtube_gdata_player
After warmup
http://www.youtube.com/watch?v=CTEIryJR0Xc&feature=youtube_gdata_player
I hope the links work
Smoke is gone form the exhaust. Good I guess. Working on unplugging the pilot screws now and lowering the floats.
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http://www.youtube.com/watch?v=vDzPIHuLwxM&feature=youtube_gdata_player
Again, right after a short ride.
Very similar to the previous.
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Check for vacuum leaks around intake boots ie cracks, loose clamps...
How many turns out are you on the aircsrew? If you are 4 turns out, you need a bigger pilot jet.
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I'll check for cracks.. I usually crank the screws on the boots down pretty tight. After I drilled out those plugs I screwed the pilot screws in all the way and it turns out that they were all only 1.5-2 turns out. Backed them out to 3 and she seems to idle alot better. I haven't gone for a test ride yet but i will soon and have new videos as well. Thanks for the help, I hope this is the fix I'll keep you posted.
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Visually no cracks. I am out of carb cleaner to spray on it to check ill do that later. After the test ride I noticed considerably more low end power and idle is still better but I'm gunna tweak it a but. Still doesnt like anything below 16k. 3 turns out so that should be stock right? It's to be expected that I should be a little further out than stock, correct?
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Stock is about 2 turns out. 3 turns is good. Try 3 1/2 turns out. Then a little more or less.
If you get to 4 turns out to fix your idle:
* may need bigger pilot jet
* Carbs may need to be syncronized
* try for 900-1,200 rpm idle
What clip are you on the needle?
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Im on the top most notch for the clip. I will sync the carbs tonight.
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If this doesn't work; check the carbon build up on your valves and make sure no gas is in your oil. Gas in your oil means your float needles need to be replaced.
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Whoops in my last post I intended to say 1600 rpm not 16k. Whoops.
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Did you only the get 117 and 120 main jets in your kit?
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Yeah my kit only came with those two sizes. Bike is running really well now. A quarter turn made a world of differance that and my petcock vacuum line was not connected to the petcock. Once I plugged that things really improved. Thanks. I plan on ridding it alot soon I'll keep you updated. One last question, what setup would require the 120 main jet? In my reading of other jetting threads I don't remember seeing anyone using it.
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Ok she's running a load better now. Sometimes this weird thing where after reving to 6k+ she'll stall fall below good idle and either come back (less common) or stall (more common). I'm not sure how this effects my normal riding besides the occasional stop light stall. But problem always presents if I do a quick rev and let the throttle snap closed. Idle is around 1400 or 1500. Thoughts?
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Do you smell gas? Yes? Check floats and rubber needle under the float, raise clip up, this will lower the needle into the carb.
Don't smell gas, try lowering the clip to raise the needle in the carb.
iMake sure all air jet screws are turned the same about. ie 3 turns out. Also try syncing the carbs....still problem? Check valves.
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By check the floats what do you mean? Ike for cracks and stuff? The rubber tips on the needles were good last time I had them apart.
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Check all that....but I was referrring to the float level. For me it's the hardest thing to get. You have to measure each one the same way and with in 1mm of each other.
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Wow I understand why the pilot screws are factory plugged. I guess I got my righty tighty lefty loosey mixed up when switching sides of the bike.... Ran them all in and backed them out to 3.25 out and she set right into a really nice idle. To anyone who reads this in the future vigilantly observe what direction you are moving the pilot screws. A simple slip of mine made my bike run like shit.
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Just curious, was that the FP 3.0 recommendation on turns out? (I've got the 1.0, which is 2-1/8)
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I'm not sure I started at 3 turns out and adjusted from there. I thought 2 turns was stock? I may try working from 2 out and see how things go. The grass is always greener.