when pulling clutch at high rpm engine dies

[zeffer111]

Hi everyone. I just bought a 1991 GSF400 a month ago.
This is my first bike and have to say generally riding it has been a blast. I've put on around 700km in the last month.
I have been lurking in the forums for a little and see there are many helpful people around.

I have been experiencing a problem with the bike. When I pull the clutch with the engine is running at high rpm, lets say, above 6k rpm, the engine dies. I have to release the clutch while in gear to "bump start" the bike while rolling.
To manage to not stall the bike, I have to quickly pull the clutch, downshift, let out clutch, and repeat till 2nd when stopping for a stop sight.
This has been happening more and more frequently recently.
It also seems to happen more when I and riding more aggressively.
Today on the last 60km of a 200km ride I was driving in 6th at around 80km/h I tried to speed up, but couldn't, and ended up having to pull over the bike because it just slowly died.
I had a couple of liters in the tank, but put it on reserve anyways.... still wouldn't start. I took out the PRI screw and turn to PRI for a couple minutes. Turned it back to res. and it started... thank god. I rode home normally.

Does anyone have any ideas as to what the problem could be? I have a 650km trip planned in another 5 days and would hate to cancel it.
Any help appreciated.

thanks

[gsxr400 racer]

try checking out your plugs if they are black get some new

[interfuse]

Why are you in sixth gear driving 80 km per h???? You are probably lugging the motor. These bikes like to have the snot reved out of them. They make NO power below 8k rpm. 6th gear is highway only... I rarely ever shift into it.

[zeffer111]

Why are you in sixth gear driving 80 km per h???? You are probably lugging the motor. These bikes like to have the snot reved out of them. They make NO power below 8k rpm. 6th gear is highway only... I rarely ever shift into it.

I was just cruising through a small town and was being noise conscious, it was when I was leaving that I wanted to speed up.

[zeffer111]

try checking out your plugs if they are black get some new

I'll pull the plugs tomorrow and check them out.

Is it possible that there is a vacuum issue with the petcock (possible clogged) and that when driving quickly in a high gear, the carbs can't pull enough fuel?
I really am pulling at straws here... I'm no too mechanically inclined.

thanks for the help.

[Banditmax]

Why are you in sixth gear driving 80 km per h???? You are probably lugging the motor. These bikes like to have the snot reved out of them. They make NO power below 8k rpm. 6th gear is highway only... I rarely ever shift into it.

Dunno what your bandit makes power like but i can accelerate smoothly from 80k in 6th if im just cruising away.

[interfuse]

Dunno what your bandit makes power like but i can accelerate smoothly from 80k in 6th if im just cruising away.

I can't say I've ever tried. The only time I ever use 6th is when I'm running out of RPMs in 5. Bandit 400s are no fun driving around low rpms. Might as well get off and push.

[gsxr400 racer]

Dunno what your bandit makes power like but i can accelerate smoothly from 80k in 6th if im just cruising away.

I can't say I've ever tried. The only time I ever use 6th is when I'm running out of RPMs in 5. Bandit 400s are no fun driving around low rpms. Might as well get off and push.

have you ever rode a 250 ninja 

[PitterB4]

Some of your symptoms also sound like they could be a blocked or kinked vent from the tank.  The next time it does it, open the tank and see if you get a whoosh from air entering the tank.

[gsxr400 racer]

 :congrats:Thats a good one and real simple but yet real important often over looked

[zeffer111]

ok, so far this is what I'm going to do.

-replace the spark plugs, because I have no idea how old they are and I would to eliminate that possibility.
-replace the inline fuel filter that I found. It was on of the clear type and I could see there was some rust deposits.

I removed the tank and petcock and tried to remove as much of the fuel as I could. What came out was orange, with lots of specks in it.

In the next couple of weeks I plan on cleaning the tank out completely and applying something like KREEM to it.
Does someone have a better product or method to recommend?

[VW_NUT]

KBC Coatings makes a nice tank seal kit.  It sealed hangin_biposto's tank up, and it was really really bad.  I MIG welded the whole bottom of the tank.

[andrewsw]

Clutch? Who uses the clutch once you're rolling? 

watch out that *none* of that sediment gets in the carbs!!!

[zeffer111]

Ok, I replaced the plugs and replaced the inline fuel filter.

I took out the air filter to clean and oil it and noticed that there was a small pool of oil at the bottom of the air box!
What do you think caused that, is it normal, should I be concerned?
I just bought the bike so I don't know too much of the history, but it could it be that they simply oiled the air filter too much?

thanks

[PitterB4]

A little oil in the bottom of the box is normal.