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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #1 ·
Okay. So this is my bandit 1200



Here is my problem. Carbs are clean and very close to a proper tune. The bike will bog only when I initially but once I open the bike up it doesn't do that again. Is only when I start moving the bike. That isn't the issue. The issue is let's say I'm riding on the highway. I can't ride the bike for a long period of time over 4,500 RPM without the bike sounding like two cylinders go dead. The exhaust sounds deeper and my power is cut in half. If I pull the clutch in and coast for a mile or pull over and kill the bike for a minute and start back up its fine. But the minute I go over 4,500 or 5,000 rpm the problem happens again. When the problem first starts I can crack the throttle and the problem will stop but only for a second. Then throttle position becomes irrelevant and the problem continues. Petcock is new. Float levels are proper. I feel like maybe the float bowls are running dry or something.. I know the bike is running rich but not so rich that its using more fuel than it can handle and my bowls on my outer carbs are drying out. But that's what I imagine is happening. Any ideas..

Also. Haven't seen any of you guys since my gar drag fighter. Glad to be back and hope you all are well...
Tank
 

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Basement Fighterer
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420 Posts
If you know its rich maybe drop the needles a half position. Only takes 20-30 mins to do. When my bike sat over the winter it seemed like it loaded up with fuel because I had to run it like 10 mins before it would rev above 4k rpm. It was shooting flames and sputtering quite a bit but after that it was fine.

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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #5 ·
If you know its rich maybe drop the needles a half position. Only takes 20-30 mins to do. When my bike sat over the winter it seemed like it loaded up with fuel because I had to run it like 10 mins before it would rev above 4k rpm. It was shooting flames and sputtering quite a bit but after that it was fine.

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Running rich in the sense of my pilot circuit being rich and running rich at cruising. Is fine at wot. Utili get this problem. Seems like fuel starvation
 

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Premium Member
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1,336 Posts
I would mess with the needles. My Bandit was sloppy and loading up at highway cruising speeds, so I dropped the needle down a position to lean it out. It fixed it for me.
 

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Old hand
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54 Posts
Have you access to a spare pair of coils ? I had the same problem on my 7/11 once.

One of the coils would get hot and break down leaving me to run on 2 cylinders until it had cooled down.
Something that may help - when it goes down onto two , place your hand (carefully !) near the headers - are all 4 the same temp ? - if one or more are cooler than the rest , it may help you trace the problem

Lee
 

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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #8 ·
I would mess with the needles. My Bandit was sloppy and loading up at highway cruising speeds, so I dropped the needle down a position to lean it out. It fixed it for me.
I'm gonna check where my needles are set. I'm just worried about it though. My motor seems to run hot already as it is

Have you access to a spare pair of coils ? I had the same problem on my 7/11 once.

One of the coils would get hot and break down leaving me to run on 2 cylinders until it had cooled down.
Something that may help - when it goes down onto two , place your hand (carefully !) near the headers - are all 4 the same temp ? - if one or more are cooler than the rest , it may help you trace the problem

Lee
No spare pair of coils. I thought that to. Had the same problem on my gs1000 and it was coil related... But I ride this bike in alltypesof weather. Same problem is happening when it's 30 degrees out. And based on the fact of how it happens. Consistently over a certain rpm. I think it's a carb thing. I'm trying to get ideas. Like I said I can crack the throttle and get the problem to stop at high rpm and it will be fine for a few seconds. Then it will bog horribly. Like I'm getting fuel starved. Then I have to kill the bike and let everything catch up. I think it may be starvation of fuel. Like I said I'm just trying to get ideas here

I have a lazer thermometer I am gonna start carrying with me and when it does this again I'm gonna hit the headers and check the temp
 

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Premium Member
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1,336 Posts
check the emmulsion tubes . sometimes they go bad and people miss it in there diagnosis
I always forget about emulsion tubes. Definitely check those for "ovaling." It seems that Mikuni thought it was a good idea to make those out of overcooked noodles for several years. If they're toast, Factory Pro should be able to set you up with a new set.
 

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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #11 ·
I always forget about emulsion tubes. Definitely check those for "ovaling." It seems that Mikuni thought it was a good idea to make those out of overcooked noodles for several years. If they're toast, Factory Pro should be able to set you up with a new set.
Emulsion tubes could be a possibility. The one on bank 4 was leaking gas at one point!!!!
I ended up taking clear epoxy and dabbing it on the spot where the tube meets the carb and sealed it up. How do those things even come off? They look like they are pressed into the carbs and don't exactly look removable. How would I change those?....
 

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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #13 ·
After you remove the main jet they just press out from the bowl side.
I just realized I was talking about something else. The emulsion tubes are in perfect order. I picked up this bike for 800 bucks with only 4000 miles on it. I was referring to those tubes on the outside of the carbs the look like burnt noodles. Haha
 

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Finaly Joined Up!!!
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153 Posts
Discussion Starter · #14 ·
this bandit is unfortunately long gone and i have been out of the country. just got back about two weeks ago. although i did figure out the problem. believe it or not very tiny cracks in the nipples of the carb hats. the cracks got bad enough that they were letting so much air in the slides on carbs 2 and three would drop unless you were at wot thanks for all of the input guys. i have an old/new project i will be posting in the member bike section. looking forward to any help and input...

~Tank
 
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