Bandit 400, bane of my existence

[Scareraven]

So my wife bought this wee bandito and I have to fix it. I have tried everything I thought of. Airbox fixed, exhaust patched, returned to normal jetting, pilot hole plug replaced, carbs CLEANED (x6), boots checked, starting fluid sprayed around carbs and airbox. 

No changes at all. 

She will idle, and choke brings the revs to about 5k. But if you touch the throttle it dies. Every time. 

My latest attempt  at a fix is I noticed that there are no exhaust gaskets in the header. Those are ordered and will be put in when I get some propane to heat the garage this week. 

Mid this doesn’t work I am afraid I will be heading towards a Viking funeral. 

I really want to love this thing. She just won’t let me...... any help is appreciated 

[Blubber]

Not a real help but....

I can predict some replies you will receive. 

Fit a turbo,

Sell as barn find, 

Fit a 600 or 750 engine, 

Convert to Efi,

Tried cursing? 

Check carbs again,  shine through every hole to check for blockage, inspect diaphragms for pin holes.

 

None of these are options you'll probably like.

[Scareraven]

All things I have considered. Always wanted a turbo charged bike, I have a ninja 900 street fighter with a new motor ready to replace the cracked one. Thinking about putting a turbo in it first. 

But the wee bandito is my wife’s bike. None stock to start....

[Askamaskinservice]

Welcome to OSS, bye the way.

@scareraven

[Scareraven]

Thanks! Lurked for a while. 

[nopokewithoutsmoke]

How did you clean the carbs?

If you haven't already, do a search on here on carb cleaning.

A set of new spark plugs might be useful too.

Good luck 

[Captain Chaos]

4 hours ago, Blubber said:

Not a real help but....

I can predict some replies you will receive. 

Fit a turbo,

Sell as barn find, 

Fit a 600 or 750 engine, 

Convert to Efi,

Tried cursing? 

Check carbs again,  shine through every hole to check for blockage, inspect diaphragms for pin holes.

 

None of these are options you'll probably like.

get another wife

[Scareraven]

I broke the carbs down completely and used carb spray and compressed air. A flash light to make sure all the passages were open. 

Mans a wife that buys bikes is pretty good. She lets me get away with a lot. She’s a keeper!

[richyrich]

Do you think it's flooding, will it fire up again after the throttle kills it, are the float valves right ?

[Scareraven]

Floats were adjusted, and she fires right back up every time. Choke or no choke. Thanks for asking. Still trying to out think the problem.  

[El Gringo]

13 hours ago, Scareraven said:

Floats were adjusted, and she fires right back up every time. Choke or no choke. Thanks for asking. Still trying to out think the problem.  

Have you got the 4 little rubber bungs in the bottom of the main jet tube? 

Have you checked the emulsion tubes for ovaling?

Sorry for linking to another forum but in my thread on Blandit Alley i went through a similar thng with my 400

http://forums.banditalley.net/suzuki-bandit-250-400/gsxr-k4-swingarm-swap/

 

Edited December 10, 2018 by El Gringo

[Scareraven]

The rubber plugs are on the pilot jet. I got them and put them on. Much to the anger of a couple of other threads. Huge arguments broke out over the purpose of those. But I want it running stick before I mess with anything. Thanks for the link!  Will read. 

[El Gringo]

53 minutes ago, Scareraven said:

The rubber plugs are on the pilot jet. I got them and put them on. Much to the anger of a couple of other threads. Huge arguments broke out over the purpose of those. But I want it running stick before I mess with anything. Thanks for the link!  Will read. 

Mine wouldn't run/rev without them in

I went round and round in circles for ages, emulsion tubes made the biggest difference

[Scareraven]

Emulsion tube ovaling is a new term for me. I pulled them and polished them. 

[nopokewithoutsmoke]

New spark plugs? Old plugs can give spurious results.

[Scareraven]

Plugs replaced in first attempt. 

Thanks for playing!

[El Gringo]

1 hour ago, Scareraven said:

Emulsion tube ovaling is a new term for me. I pulled them and polished them. 

Next time you have the carbs apart have a look down the emulsion tube where the needle runs, if it's massively ovated it'll let extra fuel through

I believe it was a big issue on 38mm BSTs with dynojet needles wearing the front edge

[johnr]

spraying compressed air and carb cleaner just doesnt cut it. first ultrasonic clean the carbs, then replace all the internal o rings in the carbs with viton o rings, these little 400s ar a bit of a carburation nightmare, if its been standing for any period of time at all, the carbs clog up. other things to check are the ht leads where they go into the ht caps, age and heat makes the leads shrink and go brittle, if they will unscrew, take them out, snip a bit off the end of the lead and then screw it nice and tight back in. also check that the tank is clean and rust free inside, finally, check all your earths and wiring connections on the bike. i know its different to the 400 kat, but thee problems seem awfully familiar to anyone who has owned a small watercooled katana thats been in storage, they just all seem to do this.

[johnr]

On 12/9/2018 at 10:46 PM, Scareraven said:

Floats were adjusted, and she fires right back up every time. Choke or no choke. Thanks for asking. Still trying to out think the problem.  

this may be  clue. starts hot or cold without choke? if its flooding the carbs due to o rings perishing or shrinking then its worth changing them. these 400s run really lean as normal. ive never seen one that doesnt require chok to start from cold when its set up right.

 

[Scareraven]

On 12/10/2018 at 9:05 AM, El Gringo said:

Mine wouldn't run/rev without them in

I went round and round in circles for ages, emulsion tubes made the biggest difference

I read your write up. That’s an amazing bike. Fantastic work. 

I have the carbs off now and will check the emulsion tubes before I put them back on. I have the exhaust gaskets but it is 33 deg this morning and my garage is not insulated. As for the flooding question, that was once the bike has been running. From cold I have always needed the choke. 

Next question: so if I’m sold on the ultrasonic cleaner, what size should I be looking at, and what kind of cleaning solution will I need?  Thank you all for your input. 

[El Gringo]

Ideally one big enough to do the full bank of carbs in one go but they're daft money

You may be better off finding someone who can do it by post

[Madb]

About 150-200 pounds should get ya one big enough. On Eblag. Make sure they're 40hz tho. You can get proper carb solution off net. @Yoshijohnny is the man to ask on here.

 

Edited December 15, 2018 by Madb
Mistake, like me

[Fula28]

Ive just read this bandito issue,s . I built b400 LTD ,one few years back the carbs are very very sensitive, To say the least I bought three sets of carbs and ultrasonically cleaned them all, New vitton o Rings in carbs  through out! New float needle seats , and check diaphragm for splits holes, My biggest problem was float cage would fall off if you hit a bump in road or just shocked it.So we used slightly bigger o rings this helped a lot, as it would bog on quick throttle  openings. Any ways like guys have said check the top of emulsion tubes for where needle passes through .Any ovaling or polish marks on needles  is a no no, Piolet jets are tiny and get blocked very easy.

So good strong solution in bath will help to clear this, try it at least 3-4 times to clean them .i run a 6ltr Gt bath. £100 ish its heated and has a drain too.

Edited December 22, 2018 by Fula28

[Scareraven]

Ok. Due to injury and wood splitting most of the summer so I have winter heat..... I’m just getting back on the ball. She lives!!

I used a hot pine sol bath for a few hours and then cleaned them until I could not smell pine sol. The choke plugs then seized up. I pulled them out and polished them all and they work a treat now. Getting everything back together let her actually roar through the rev range for the first time!!!  Response is a little fluffy, but I will balance them to clean it up. 

I put the tank back and I could barely get it to idle cleanly and it revs shitty. The clear fuel filter showed me that it was starving for fuel. Tank off and iv fuel line back on, she runs fine. 

New petcock ordered. 

Mom dying to get this thing on the street!

 

thanks to all the suggestions and help!

[Captain Chaos]

great success!