Bogs down with throttle

[Bandit400]

When i apply throttle it reverses the affected it revs down till it stalls

[bullet5]

Do the revs drop smoothly, or lumpy?  Will it rev upwards at all?  If so does it rev then stutter it's way down (Sound as thought it's missing?) after a while of running?  Has this problem been there since you bought the bike?

It sounds like 1 of 3 things to me. Either the throttle cables are attached the wrong way around, the fueling is massively rich, or your bike is suffering from carb icing.

All the best,
Bullet5.

[Bandit400]

It goes down smoothly but i think its running madsively rich cause it does t start anymore whats stock turns for air/fuel cause i cant get it started anymore

[bullet5]

It goes down smoothly but i think its running madsively rich cause it does t start anymore whats stock turns for air/fuel cause i cant get it started anymore

I see you've had a play with the throttle cables on another thread. I'd double check that before playing with anything else.  As for your air/fuel ratio, what year/model is your B4 and is it a VC or slingshot engine?

Bullet5.

[Bandit400]

Im sorry what do you mean slingshot? Or vc?

[Bandit400]

By the way its a 1992 bandit 400

[TJS]

Take this to the 250/400 forum for more help.

Do you have a jet kit, pipe, K&N filter? All stock?
Did you check the cable routing as mentioned above?
Did you accidently put a permanent bend in the cable when installing it at the carbs?
Is their gas leaking from the bowls?

All looks good?

Raise your clip by 1 or 2. This will lower your needle.
Turn your air screw to 3 turns out

[Bandit400]

I have it 3.5 i have no clue if it has a jet kit or anything but the exhaust sounds mean its super loud so id assum i need more gas but on the needles it actually only has on level cant change it no gas leaking

[bullet5]

Im sorry what do you mean slingshot? Or vc?

There are two types of engine fitted to the 400's.  One is a standard engine with 2 valves per cylinder, the other has variable valves.  This opens just two valves (one inlet, one outlet) at lower revs (pre 8k) then after that figure the VC unit would kick in and would instead utilize 4 valves per cylinder (two inlet, two outlet).  This provides improved air flow, and helps achieve a more complete burn, which in turn produces more power.  Mk1 B4's had VC attached to both inlet and outlet cams. The Mk2's only utilized VC on it's outlet cam.

There are a few ways to tell apart a standard (non-vc) engine from a VC one.  Normally the standard engine is painted a sandy gold colour like so:



A VC engine is normally black with a red rocker cover, hence the nickname "Red Top".



The VC engine also has the letters "VC" stamped on the sides just below the rocker cover (as shown in the picture above).

Being a 1992 yours is a Mk1 bandit, so it should be running a Mk1 engine, however these bikes have been played with so much that it may have an engine from a Mk2 fitted.

On another note, having a "super loud" exhaust doesn't mean it requires more gas, it just means you've either got a race/straight through exhaust fitted, or you have an airleak in the exhaust manifold.

Bullet5.

[Bandit400]

I do not have a vc engine

[Bandit400]

Okay so heres the news i sent it to iron pony for a diagnosis cost me 156$ they said compression was 150 150 150 145 needed new clutch cable throttle cable coils and spark plugs(i fouled 4 sets already) the coils spark blue(i think) or atleast yellow should it still it start? Oh yeah theres also gas in the oil? I just changed it literaly, respol 16$x3 + filter. Full synthetic there estimate 1900$ unfortunately i dont have the money and it costs more than the bike is worth need help... Lol

[rider123]

That's actually pretty good compression values(which is a plus). I would definatley look at the carbs. With the shit they put into gasoline these days I'm sure it's not doing anything great for the diaphragms  or o-rings. If you wish, PM me and we can talk on the phone and I'll try to help you sight unseen and try and get you back on the road safely. I'm assuming you've done a plug check correct? The 400/250 series of bike were a little notorious with O-rings dying quicky which would cause a rich condition at certain rpms. Before you spend anymore money, it might be good to have a little chat. Nice looking bike BTW. Mine looks like hell, but boy did I make it go fast!(scary 1200). I can't believe they charged you $156 for a simple compression check, which is BTW  outside the norms for such a simple test. While I understand that we should support our local mechanic, having people charged for such a simple procedure should be dismissed. My friend owns a motorcyle shop and the is no goddamned way he would ever charge that kind of money. If you need help please PM me, I may not be able to fix the problem completely, but I will can at least point you in the right direction. That is completely  a ludicrous amount of money. Let's look at the problem, not the symptoms. The invitation is open.

[Bandit400]

Thanks for the offer but i actually sold the bike and went with a 1992 fzr 600

[rider123]

Great bike! I'm glad you resolved the issue. I'm assuming that you're going to the FZR sites now,however if you still need help, don't be afraid to ask,. My friend owed an FZR, brand new in '87(God I feal old) so if you need some support do not hesitate to ask.

[Bandit400]

Yes i am recently the wind pushed it over into my friends bike and it actually bent both of the mirror stays so i cant do anything till i buy those used theres one minor problem it idles at 2k when completely hot?