Hesitation issue

[Ripken]

Now that the weather has warmed up I've noticed an issue of hesitation for the first mile or so on the 1250. But it doesn't happen all the time, only the day after I fill up with gas. I typically take a long 200+ mile ride on the weekends. Upon returning I will stop and fill up at a gas station a few miles from my home. The next morning, all is well, but that afternoon when I start the bike to head home from work it will hesitate badly in anything more than 3rd gear for the first mile or so.

I park the bike in my garage, so when I crank it up in the morning it is nice and cool, whereas it sits outside in the hot sun all day while I'm at work. I admit that I tend to top off the tank to maximize the amount of gas I'll have for the weekly commutes. Is the gas expanding in the tank during the hot day so much that I am creating a pressure issue that is affecting the fuel pump? The bike runs absolutely hesitation free the rest of the week, experiencing issues ONLY the day after my latest fill-up each week.

Thanks in advance for any assistance the folks on here can provide.

[MetrickMetal]

Originally Posted by Ripken

Now that the weather has warmed up I've noticed an issue of hesitation for the first mile or so on the 1250. But it doesn't happen all the time, only the day after I fill up with gas. I typically take a long 200+ mile ride on the weekends. Upon returning I will stop and fill up at a gas station a few miles from my home. The next morning, all is well, but that afternoon when I start the bike to head home from work it will hesitate badly in anything more than 3rd gear for the first mile or so.

I park the bike in my garage, so when I crank it up in the morning it is nice and cool, whereas it sits outside in the hot sun all day while I'm at work. I admit that I tend to top off the tank to maximize the amount of gas I'll have for the weekly commutes. Is the gas expanding in the tank during the hot day so much that I am creating a pressure issue that is affecting the fuel pump? The bike runs absolutely hesitation free the rest of the week, experiencing issues ONLY the day after my latest fill-up each week.

Thanks in advance for any assistance the folks on here can provide.

This sounds as if your experiencing a problem a lot of 1250 owners have when they fill their tanks up, and if the gas tank gets heated from sitting out in the sun, or parked in a hot garage, the fuel can get pushed up into the EVAP canister, then when you take off and shift into either 3rd gear or higher, the ECM energizes the EVAP canister control valve, which would normally just suck the gas fumes back into the intake system to be burned, but instead it now allows the liquid gas to get sucked back into the engine which can cause the problems your having and even make the engine stall out.

Removing the EVAP canister and the associated plumbing will eliminate this problem, and remove about 3 1/2 lbs off weight off of your bike, and removing the PAIR system removes another 1 1/2 lbs of weight, and with both of these systems removed it really clean up the top of the engine.

http://i247.photobucket.com/albums/g...e/IMG_1136.jpg

[Ripken]

Thanks for the answer MM. I wish I lived close to one of you gurus so that you could help me with and/or perform the necessary work. Am I doing any damage to the engine? By the timing, I'm guessing if I don't fill it up with as much fuel the problems will most likely go away.......would you agree?

[Tazman2]

Correct. I usually just tank up while I'm out riding and I know it won't be out in the sun for hours, etc!

[kewwig]

Originally Posted by Ripken

Thanks for the answer MM. I wish I lived close to one of you gurus so that you could help me with and/or perform the necessary work. Am I doing any damage to the engine? By the timing, I'm guessing if I don't fill it up with as much fuel the problems will most likely go away.......would you agree?

Anything that pushes gas in a liquid form into the engine will contribute to bore wear as it has a flushing effect on the fine coating of oil. May be something you never notice, but in theory it's not a good thing.

[Ripken]

Thanks for all the answers guys. I appreciate the help!

[achesley]

Worst bike I ever had for that was my '95 R11GS BMW. If you over filled it just a little, it went to the canister and fed to the intake system. La YUK!. Till I dumped the system and vented the gas tank to ground. Oh, I didn't say that.

[1CAMWNDR]

I am having the same problem with my Bandit, but in all gears below say 3,500 rpm. My EVAP and PAIR have already been removed. I guess I am going to try and mind how much fuel I put in closer and see if that eliminates the issue.

[CWG]

Sounds a little similar to what I have, but only at lower revs. Haven't equated it to the full tank yet, though now I'll pay attention.

Any of you guys have experience with their 1250's with an aftermarket exhaust causing surging, stumbling? I bought mine recently with a two brothers slip on and it sounds great, but was told it might lean out the mixture too much and make it run not smoothly.

Dealer told me to put on a power commander, which would help with mixture, but not sure he doesn't just want to sell me some more stuff.

If you guys have experience with it, I'd love to hear..

CWG
2007 Bandit 1250

[1CAMWNDR]

Originally Posted by CWG

Sounds a little similar to what I have, but only at lower revs. Haven't equated it to the full tank yet, though now I'll pay attention.

Any of you guys have experience with their 1250's with an aftermarket exhaust causing surging, stumbling? I bought mine recently with a two brothers slip on and it sounds great, but was told it might lean out the mixture too much and make it run not smoothly.

Dealer told me to put on a power commander, which would help with mixture, but not sure he doesn't just want to sell me some more stuff.

If you guys have experience with it, I'd love to hear..

CWG
2007 Bandit 1250

Get a hole of Dale at Holeshot Performance. He will sell you the Power Commander and tell you what settings to use with it.

[CWG]

Appreciate it!

[Tazman2]

Originally Posted by 1CAMWNDR

Get a hole of Dale at Holeshot Performance. He will sell you the Power Commander and tell you what settings to use with it.

"hole" lol pun intended by accident!? Anyways he doesn't sell the Power Commander he sells a different unit either way great guy and great results! Also if you have high mileage (I have almost 17k) it could also be the throttle bodies need a sync big time! They are suppose to be done twice already for me and I haven't done it even once and I'm starting to pay for it!

PS: You can also check for too much play in the throttle it might need tightening! I've done mine maybe 5 times already!?

[CWG]

I was looking at a Power Commander, but thanks to 1CAMWNDR and speaking with Dale yesterday, he talked me into his kit. Should be shipping out today. Pretty hard to believe he speaks to each one of his customers, but very cool.

I've heard a lot about syncing throttle bodies. Is that a big job?

I'll look into the throttle linkage as well.

Thanks for the advice. Nothing like first hand testimonials.

[1CAMWNDR]

Originally Posted by Tazman2

"hole" lol pun intended by accident!? Anyways he doesn't sell the Power Commander he sells a different unit either way great guy and great results! Also if you have high mileage (I have almost 17k) it could also be the throttle bodies need a sync big time! They are suppose to be done twice already for me and I haven't done it even once and I'm starting to pay for it!

PS: You can also check for too much play in the throttle it might need tightening! I've done mine maybe 5 times already!?

HA! Totally accidental but totally cool. LOL!

I forgot that Dale's tuner is something else. DOH!

[CWG]

To keep it going, hopefully it will solve the "hole" problem.

I'll be doing Stage II. Really looking forward to it.

CWG

2007 Bandit 1250S
Two Brothers Slip On
Soon to be Stage 2 Holeshot
Ear to Ear Grin

[Tazman2]

Aside from the intense power/noise increase at higher revs the bike will run tons smoother even on throttle transitions. Dale really has the kit down right I refuse to ever sit on a pre stage 2 Bandit ever again!

[CWG]

Tazman,

How is the Zero Gravity Shield?

I'm 6' and the stock shield isn't bad, but could be taller, I think.

[Squid4Life]

Perhabs i could help you..i am 6'2 and im using the zg touring shield....way better than stock(needless to say) but i still get some buffering, my biggest complain would bethat it doesnt push air to the sides as much as i would like.

[1CAMWNDR]

Meh, pull the windsheild and fairing off and install a big ole 7" headlight. At 6'7" I don't think any windshield would have kept the wind off me. I love the naked look; and it gives me an abdominal workout holding myself upright on the interstate at 75mph!

[CWG]

LOL. Not much going to protect you except sidling up to the back of a semi.

I'll look into the ZG shield. Not looking for the Goldwing experience, just a little bubble to get behind on a long ride.

CWG

2007 Bandit 1250S
Two Brothers Slip On
Soon to be Stage 2 Holeshot
Ear to Ear Grin