Bandit Alley

MODEL SPECIFIC => SUZUKI BANDIT 250 & 400 => Topic started by: GK75A on August 06, 2006, 06:20:39 AM

Title: 5000 rpm flatspot
Post by: GK75A on August 06, 2006, 06:20:39 AM: bandit parked up 4 years , new battery, plugs, rebuilt carbs with new seals. air-screw out 2 & 1/4 turns out but it bogs down from 5-6 k. then it clears and takes off. any ideas?
Title: 5000 rpm flatspot
Post by: PitterB4 on August 06, 2006, 08:52:36 AM: More info, please. :grin:

Is it just a slight hesitation or a real bad bog? Does it get better when it warms up? Mods - exhaust, air filter, jet kit?
Title: 5000 rpm flatspot
Post by: GK75A on August 06, 2006, 11:51:47 AM: oops, my bad.
its a 92 uk spec bike, everythin is stock. i`ve balanced and re-checked the carbs but still the motor struggles to make any progress btwn 5-6k. once past 6k it clears itself and really takes off. i had set the air screw to 2 1/2turns out but this had a worse dip in power btwn 5-7k. it has improved by air screw at 2 1/4 turns but im concerned as to further adjustment because most other posts suggest 2 1/2 - 2 3/4 turns out.cheerz in advance for any help
Title: 5000 rpm flatspot
Post by: BrianM on August 06, 2006, 01:35:35 PM: Well, that flat spot would be tied to the needle (height typically) more than anything else. It'd be worth popping off the diaphragm covers and pulling the needles to see what's going on there. If there are shims lifting the needle, then remove them and see how it goes. If there aren't any, put some (2.5mm washers are what I use ~ 2 or 3 of them tend to do the trick) under and again, see if that makes a difference.

They're quick and easy to get to, so you should be able to run a few tests in a typical day and see what's better and what's worse... then just keep going in the 'better' direction till it starts to get worse again, and then go back a step or two.

Best of luck.
Title: 5000 rpm flatspot
Post by: gsxr400 racer on August 06, 2006, 05:05:46 PM: :duh: Dont you ever only use 1 washer cause you are just trying to go a half a stef on the needle 2 or 3 you might as well just move the clip
Title: 5000 rpm flatspot
Post by: BrianM on August 06, 2006, 08:59:14 PM: Uhhhh... STOCK needles don't have clips Jay.

I've never found reason to spend the $100+ for a jet kit on any of my bikes, can't justify the return on investment.
Title: 5000 rpm flatspot
Post by: gsxr400 racer on August 06, 2006, 11:36:21 PM: well the needle taper is what you pay for!
Title: 5000 rpm flatspot
Post by: BrianM on August 07, 2006, 12:49:48 AM: Like I said, *I* can't justify the expense. I don't buy bikes and try to make them faster/more powerful (other than doing basic maintenance) because it'll Always be easier to just buy a bike that's faster/has more HP. Just a huge waste of money to gain a tiny percentage of HP.

Shimming the stock needle, putting in smaller main jets (I'll have 90's in the B4 shortly as 95's are too rich), and adjusting the A/F mix screw always solves the ills that hinder street riding. Actually, for once I'll need to put smaller pilot jets in too... but I haven't been at 6k feet in elevation with most of my previous rides.

To each their own, but I'll keep that $100+ in my pocket (and the $400 for a pipe too), or just toss that money at a rebuildable shock/cartridge forks.
Title: 5000 rpm flatspot
Post by: GK75A on August 07, 2006, 08:04:48 AM: ive taken the air screws out to 3 turns and its gettin pretty close now, just a slight dip at 6k now.im gonna have another play next weekend.
cheerz