Bandt cuts out

[captnhooks]

Bike flat out dies at anything above 4100 rpm!!

Riding along at 44 to 5k and it just shuts off, like the kill switch was touched, pull in clutch, speed reduces let clutch out and blaaaaaaam she comes back to life. Hold at 4100 and it wont die, anything above that it will WHAT THE HECK??

[captnhooks]

its a 2000 B12s i have bought new carbs and new factory airbox, new hoses, and what not because it did this with the old carbs on as well!! Cleaned the tank lines as well and rebuilt the petcock. Any one have this issue??

Im beginning to think there is nothing wrong with fuel delivery at this point because it just cuts off, as if the kill switch was tipped.

[ventYl]

if the engine cuts off, in the time until you pull the clutch, does tacho show engine RPM or the needle falls down to 0?

[captnhooks]

To Tell you the truth , I Dont recall. Ill have to look again, but Im Pretty sure its shows some RPM because its still turning the motor at 70+ mph. Thats a dern good question

[ventYl]

Yes but with B12 engine tacho is driven by ICU. If the ICU losses signal from engine crankshaft sensor or some failure inside ICU is present, tacho may drop to 0. While probably all of the ICUs for all Bandit ever made contain CPU which controls things like spark advance and rev limiter i don't expect that some analogue part of ICU is broken and for example rev limiter is dropped down to 4100 RPM.

If this test will be negative (e.g. tacho still shows RPM) then next step will be to connect stroboscope to spark plug wiring and rev the engine with bike on stand. This assumes that this problem is reproducible with bike standing still. If after going over 4100 RPM stroboscope shuts down then problem is in ignition, otherwise in fuel system.

Personally... I bet that problem is in ignition because fuel system problems are often not bounded to strict conditions and vary with impact and triggering situation. If the problem is really so exactly triggered then the problem should be of electrical origin. Unfortunately I never saw B12s ignition so closely that I can provide some narrower help.

edit: if not for any other reason; fiddling with ignition is more safe than fiddling with fuel. less chance to burn fuel fumes when no hoses are disconnected.

[captnhooks]

Yeah I head ya on the fuel comment!! Sadly I Hate Electrical issues, as it could be something so simple as a wire touching somewhere. Ill See if I cant take it to a buddies shop and place it on a dyno roller. Its good to know peeps sometimes, but its still never free!! Lol Thanks for the advice bud!!! Ill keep this posted as I discover what the issue may be!! I too am Leaning towards an electrical problem... UGH

[captnhooks]

Crazy Story!!!  I Put my Bandit up for sale about a week ago as im really tired of dealing with the bike cutting out and I just cant seem to figure it out!! This older gentleman shows up after calling me to come take a look at the bike!! I Pull it out of the cuby hole from my garage and fires right up, always has since the new carbs were put on! Guy asks me if there is anything I need to be alarmed about. I told him about the issue, and that I will miss the bike as I have put a ton of time and some money into it!

He revs it after it warms up looks over a few things we talk some more. Then he looks right at me, and says "If I tell you whats wrong with it, will you keep the bike?" Sure as long as Im not dumping another $300 at it. He then grabs one of my paddock stands and lifts the rear up as my bandit has the 1 inch lift so the tire sits on the ground on the center stand. Grabs the clutch and pops it in gear, goes all the way through the gears. Looks at me and points down, So I walk around the bike and he just barely touches the kick stand .... BLAAAUAUUGH..... Silence! He then tells me what i need to do, Shakes my hand, and tells me that there are many more years of bike time with "Dad" still to come

Turns out the switch was just barley touching the side stand and the vibes and wind can more it just enough to kill the bike for that split second. Hence why the bike would start up every time afterwords!! It also turns out he is a neighbor that has seen both my son and I and my wife and I on the bike. Did the loop and rode the shiet out of it tonight!! Not A Single hickup!! Who needs the damn side stand switch anyways, hell who uses the side stand when we have center stands!! LMFAO

[djnatedogg]

I like hearing stories like this that verifies there are some decent people out there still!  Glad you figured it out.  Now take that guy out for a beer!!

[captnhooks]

All ready took him a case of PBR . LOL Even delivered it on the bike!!! So damn happy this issue is fixed!!

[djnatedogg]

Good man!!