Author Topic: Re: my GSF400P problems  (Read 7737 times)

Offline banditopocket

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Re: my GSF400P problems
« on: January 10, 2016, 05:02:15 AM »
Hello,

I just got my bandit at $3000 dollars.

its $$&%$#@ing expensive here but I love it.

The problem is:

When I turn on my signals, all of the other light(Brake light, headlight, neutral light) flashes with it. any idea whats the issue? I went to the mechanic and he said that it was supposed to be like that.  :duh:

I seem to have problems taking my B400 for long distance rides. It always die on me after 20 minutes of riding after which it just dies then i would crank the engine and it just wouldn't start. The mechanic says it's an issue of the fuel tap so i swapped it costing me $150 %$#^@#ing bucks and it still occurs. He recommends that i change my fuel cap now. Any idea if the fuel cap have any other function than to keep fuel in? The previous owner painted the fuel cap.

I am really new to such bikes and any help will be much appreciated !

Offline Squishy

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Re: my GSF400P problems
« Reply #1 on: January 10, 2016, 05:28:53 AM »
Congrats on the b400!

.. But I have to ask.. $3000? Unless it was in mint condition with 10000kms max.. I don't see how?
Over here they go for $500-$1000.

Anyway. The cap can cause issues when the small vent hole gets clogged. Your carbs will eventually (like after 20min) suck the tank into a 'vacuum' and it won't be able to get any more fuel from the tank. You can simply test this by going for a ride with the cap slightly open.

I don't see why he would recommend to replace the cap though. You just have to clean it.
Same goes for the fuel tap. Why would he tell you to replace it for $150 without diagnosing whether that's the problem?
It's pretty easy to test whether the fuel tap/petcock functions properly.

About the blinkers, sounds like you got some wire harnass problems. I'd suggest looking at the wiring diagram in the manual. Maybe someone else has some experience with the same problem.

Offline banditopocket

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Re: Re: my GSF400P problems
« Reply #2 on: January 10, 2016, 06:28:12 AM »
Wow, thanks for the swift reply.

I'm from  asia so 3k in a different currency .

I tried to start my bike with the fuel cap wide open but it doesn't work. Waited an hour and tried again with choke and fuel cap open, doesnt work. I was reading about that and found that i should be able to expect a swooshing sound with air going in when i pull open the tank cap but i heard nothing.

He replaced the fuel tap because there wasn't an option to off the tap. My previous fuel tap had On and Res previously. Now it comes with an additional option to Off at $150. -_-

Offline Squishy

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Re: Re: my GSF400P problems
« Reply #3 on: January 10, 2016, 07:05:04 AM »
Wow, thanks for the swift reply.

I'm from  asia so 3k in a different currency .

I tried to start my bike with the fuel cap wide open but it doesn't work. Waited an hour and tried again with choke and fuel cap open, doesnt work. I was reading about that and found that i should be able to expect a swooshing sound with air going in when i pull open the tank cap but i heard nothing.

He replaced the fuel tap because there wasn't an option to off the tap. My previous fuel tap had On and Res previously. Now it comes with an additional option to Off at $150. -_-
The original fuel tap is vacuum controlled - meaning that the fuel tap is always in the OFF position, unless the engine is running and the carbs are sucking the fuel tap open (there's a hose connected from carb to fuel tap).
In fact the original fuel tap has 4 options - default OFF, ON, RES, PRI (pri might not be mentioned but it is UP on the fuel tap).

edit:
Yeah if it has sucked vacuum you will hear a swoosh sound.. but this only after riding.
When the bike has been sitting the tank will likely lose vacuum because it is never perfectly air-tight. Should give no problems after it has been sitting.

You can check whether there's fuel in the carb bowls? Slightly open the drain plug on the bottom.
What kind of fuel tap is the new one?
If it is not vacuum controlled - what did you do with the vacuum hose from the carb mentioned above?
« Last Edit: January 10, 2016, 07:11:14 AM by Squishy »

Offline ventYl

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Re: my GSF400P problems
« Reply #4 on: January 10, 2016, 09:01:39 AM »
Isn't there some auxiliary fuel filter mounted in between fuel tank and carbs? Wrongly placed filter might cause problems similar to yours. With the filter even tank vacuum levels which normally won't produce hearable sound when cap is opened might cause engine to stall. I've had filter which caused the engine to stall with cap which was okay. Also, how is the fuel line routed? And how old is it? It might be cracked on inside causing slowed down fuel flow.

The electrical problem, I assume that you have somewhat moist climate so it would be the best to strip the bike completely and clean all harness connectors. Some of them might be rusty, or not tight enough causing voltage drop across contacts causing flickering. In your case most probably it will be somewhere around negative connections. Either light circuit harness or battery itself.

I don't think it is generator issue because in case of generator failure the condition of electrics would get worse over time due to battery being discharged by the lights and starter. It might be issue with aged battery but in such case you'd experienced voltage drop after many attempts to crank the engine.
Bandit 400 1991 - stock except of swap from GK75B to GK75A

Offline bdouvill

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Re: my GSF400P problems
« Reply #5 on: January 11, 2016, 05:43:35 AM »
Issue of engine dying after 20 minutes (so when hot) makes me think about an air issue. Might be the carb pipes not properly tighten. Check pipes on the engines, carbs off, the collars holding the carbs on the pipes (typical issue).

Also once, I had the same behavior because on the washer on one of the spark plugs went on the side on the spark plug thread instead of staying flat. So big air problem on one cylinder after 10-15 minutes of riding. But this one is more unlikely than the pipes.
Benoit.
Bandit 400 1992, 1st bike.