S.O.S Bandit 1200

gammaguy21

gammaguy21

Well-known member
My brother bought himself a 2004 Bandit 1200 a couple of years ago.
Last year it started acting up and then wouldn't start at all.


I figured I'd give the carbs a clean and we managed to get it started.
I had the petcock on PRI when we stared it and it ran until gas started coming out the bottom of the air box!


508ee06c-b0cf-4f27-b77f-092add886cfa_zpsoq6rnhn9.jpg



It was late and I didn't check the engine oil for gas, but I'm concerned that gas may have gotten into the engine?


1) Should I change the oil, pull the plugs and give it a few cranks, before I try to start it again?
2) Anyone know what stock jetting is? He's got an aftermarket exhaust and a hole cut into his airbox... so, I'm guessing his jetting is no longer stock.
3) I guess the needle float valves need to be changed? Is Bikebandit best for parts?
4) I had to slide the carbs out the side because the stupid airbox wouldn't come out. Any tips to get these out easier? What a pain!


Here's a pic of his plugs as well... they look rich.
20160312_183722_zps9xl57pfu.jpg
 
the carb floats need to be set, they are overflowing....

Yes, check the oil - change it - if its been fouled with fuel. Those plugs look worn - put in a set of plugs.
 
Is that a trick of the camera or is the side electrode on plug #3 actually bent? The plugs also appear to be mismatched - I'd chuck 'em.

And don't mess with the jetting yet, it is not the cause of your current problem.
 
Thanks guys.
New plugs on the way... TwistedKestrel, I didn't notice anything odd with plug #3, but I'll have a closer look now that you've mentioned it.
Oil change on the list too.

Input much appreciated.
 
edited

if gas is "flowing" out of your airbox i would say your float(s) aren't just leaking (though it may be) - i would say the float(s) are "stuck open" . this is like a toilet that doesn't stop running until you shake the handle. this can easily happen when putting the carbs together after service. sometimes you can just tap each of the carbs smartly with the blunt end of a screwdriver to dislodge the hung up float (try this repeatedly from different directions-sometimes you get lucky) for 1-2 minutes on each carb before going through the trouble of removing the carbs from the bike. otherwise you need to take carbs apart and make sure the float(s) aren't sticking/stuck or leaking at a dirty or worn needle/seat junction. when you cleaned the carbs did you remove the floats and check / clean the float valves too?


edit - when you have the carbs off the bike, try not to hold them upside down or too far sideways or using them for juggling. as the float(s) can get "hung up"

also make sure when you put the carbs on that all the boots are sealed perfectly and don't make any rips in the boots ... this is a common oversight - take your time so another issue doesn't compound things.

the more carbs you r & r the easier it gets -
 
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I won't worry too much about the gas in the oil, it will burn out when you run it at operating temps. 2 of your cylinders are running rich. They might not even be firing at all. Is the engine running smoothly?
 
Thanks guys.

boyoboy, do you mean not to hold the carbs right way up with the floats dangling in the air?
I'll try tapping the floats and make sure I've got a good seal on the boots. Was going to test for air leaks once I had it all up and running.

Rockerguy, from what my brother told me it was running ok, and then progressively got worse until he couldn't start it.
He had the carbs cleaned and the valves set by a local bike mechanic, but the issues started soon afterwards, and he ended up with some sort of gas leak.

Come to think of it, the float on carb #3 was a few mm out (about 16mm), and I had reset it to the 13mm suggested height. I wonder if that had anything to do with it?

I found a e-copy of the workshop manual, so I now know what his stock jetting was supposed to be. I won't change anything until he's ridden it for a bit.
I've come across some sites that suggest his setting are consistent with the air box mod and aftermarket exhaust.

I've read on two strokes gas leaking into the engine from a leaky petcock valve could cause a hydrolic lock and could create issues if you try to start it... which was my main concern.
 
gammaguy21 said:
Thanks guys.

boyoboy, do you mean not to hold the carbs right way up with the floats dangling in the air?
I'll try tapping the floats and make sure I've got a good seal on the boots. Was going to test for air leaks once I had it all up and running.

Rockerguy, from what my brother told me it was running ok, and then progressively got worse until he couldn't start it.
He had the carbs cleaned and the valves set by a local bike mechanic, but the issues started soon afterwards, and he ended up with some sort of gas leak.

Come to think of it, the float on carb #3 was a few mm out (about 16mm), and I had reset it to the 13mm suggested height. I wonder if that had anything to do with it?

I found a e-copy of the workshop manual, so I now know what his stock jetting was supposed to be. I won't change anything until he's ridden it for a bit.
I've come across some sites that suggest his setting are consistent with the air box mod and aftermarket exhaust.

I've read on two strokes gas leaking into the engine from a leaky petcock valve could cause a hydrolic lock and could create issues if you try to start it... which was my main concern.
Click to expand...

you can hold the carbs anyway you want - just be aware that the floats can hang up - and dont use the carbs for juggling before putting them on..know what i mean? i've edited my post in an effort to be clear. now, based on your mention of the gas flowing earlier, before the carbs were removed from the bike, i'm beginning to think your float valve(s) may be suspect. did you have the float valves apart for a close look when you cleaned the carbs? take a close look at the needle seat area for dirt or wear marks.
 
check all the carbs float valves carefully in the needle/seat junction area for dirt / debris / wear on seat or needle

you are on the right track - if you have concerns about gas filling a cylinder you can crank the motor over a few seconds with the plugs out to clear out any fuel. i would be sure to have the kill switch in the off (not running position) before cranking to clear fuel, to keep ignition spark gas explosions to a minimum). try not to leave bike in the prime position unless you are trying to start/work on the bike.

edit - let us know what you find when you check out the float valves. nothing wrong at all with correcting float height, but i don't think being out 3mm (which is a considerable amount) would be the source of the gas leaking. perhaps someone could chime in on this..

i would look extra carefully at the float valve of the carb that had the float height spec out 3mm
 
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boyoboy said:
check all the carbs float valves carefully in the needle/seat junction area for dirt / debris / wear on seat or needle

you are on the right track - if you have concerns about gas filling a cylinder you can crank the motor over a few seconds with the plugs out to clear out any fuel. i would be sure to have the kill switch in the off (not running position) before cranking to clear fuel, to keep ignition spark gas explosions to a minimum). try not to leave bike in the prime position unless you are trying to start/work on the bike.

edit - let us know what you find when you check out the float valves. nothing wrong at all with correcting float height, but i don't think being out 3mm (which is a considerable amount) would be the source of the gas leaking. perhaps someone could chime in on this..

i would look extra carefully at the float valve of the carb that had the float height spec out 3mm
Click to expand...

Great info boyoboy. I only noticed the #3 carb float just before I put everything back together. I'll have a look at that need valve specifically when I have them apart again.
 
Okay.
So oil changed, definitely had gas in it.

Dried all the gas in the airbox and pulled the carbs.
Got new needle valves for all four carbs and replaced them. Made sure the pins holding the floats were clean and the floats were moving freely.
Rechecked all the float heights. When I pulled the brass seat for the needles I did notice that #3 was really easy to pull, so I'm guessing the o-ring had gone.

Turned it over without the plugs and kill switch to off.
New spark plugs... but I forgot to check the electrode on plug #3.
Primed the carbs, pulled the tank and left the airbox off just to see if any gas was leaking.

Fired it up and it started without issues!
Gas tank back on and fired back up and no leaking gas.

Here's a pic of the needles, they are in order of carb.

20160319_171748_zpszd64tvxf.jpg


I have a couple of more questions before I can put this to bed... I'll ask later as I've a man cold so, going to get some rest.

Thanks for the help!
 
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