1999 Bandit 1200 needs mechanic

[rphillips]

Recently purchased 1999 Bandit 1200 S. Great bike "BUT", while just crusing, just maintaining speed, 40, 60, 75, engine misses & blubbers constantly. As soon as the engine gets in the slightest pull or strain, give the thing the slightest throttle or start up a moderate hill, the engine smoothes out, purrs, pulls, & runs like a perfectly tuned engine. I've ridden it appx. 1000 mi. & it doesn't seem to be hurting anything yet, I haven't noticed any differences so far, but I know it can possibly keep getting worse. With mechanics charging towards $90 pr hr. won't take many hr. labor & it may not be worth fixing. Just looking for suggestions. Thanks

[Nessism]

Does the bike have a modified exhaust and/or intake system? Is the air filter clean?

[rphillips]

V&H slip on, orig air box & clean filter, don't know about carb jetting.

[bonanzadave]

If its anything like our old GSs even a small air leak can cause trouble. Is the airbox lid tight ? Are there leaky boots or gaskets between the engine and carbs ?

[Nessism]

I'd try tweeking the pilot screws, assuming the bike has them. Most likely the exhaust has messsed up the mixture.

[rphillips]

I've got far enough in life my eyes, hands, fingers, & brain don't work like they did 30 yrs. ago. I've tried to see the boots were straight & all the way on, clamps were tight, & covers were properly in place. Everything looks good & unmolested, but I'm not sure of anything

[rphillips]

Wondered about the exaust, a complete system should affect the carbs but figured a slip on was for sound & weight.

[Jedz123]

Check you float heights. These bikes are temperamental as crap with that... Trust me check em!. 14.7mm is the sweet spot. While your in there make sure your still running stock mains. 102.5 off the top of my head.

I'll tell you though I'd recommend upgrading to a K&N filter with 2" hole. In the air box. Run 127.5 mains and 35mm pilots. Also add a shim to the stock needles. It will be a new bike trust me... good luck!

[blowerbike]

i had a guy who's pilots would close up twice a year on his 1200 and i would have to clean them.(lack of riding)
if you had a set of rs36/38's to toss on it and go for a ride you will see it's a carb problem.
just my opinion.

[rphillips]

Thanks guys, Of course I baught it like this so I don't have a clue how long it's been like this, Don't have a clue when the V&H was slipped on or if it's been running like this since then, or may have sat for an extended time, then when got out & fired up it may have been like this. 8000 mi. on a 13 yr. old bike, it's sure sat sometime, no way to know when or how long. Also not sure of jets or shims, I got no history as I baught the bike from a "used car lot", of course they knew nothing about it. I apreciat the opinions, that's what I was was wanting, but if anyone has a guaranteed fix, come on down & I'll pay you to fix it. Thanks again guys

[Jedz123]

+1 with Terry. Clean out your carbs first. Sounds like she's starving in the pilot circuit. You can try running seafoam through a couple of tanks but a proper cleaning is definitely in thr cards. Also get you floats to the proper height. I was chasing a similar issue on my old B-12 and it was the float heights the whole time. To avoid the issue run Stabil marine formula every fill (blue Stabil). I cleaned my carbs once on my B-12 and never cleaned them again after all the adjustments were set..of course the bike never sat and saw 10-15k Miles a year...

FYI...

[Tazman001]

Little help with pics

Check you float heights. These bikes are temperamental as crap with that... Trust me check em!. 14.7mm is the sweet spot.

can you post a pic of that? I'm goin' thru the carbs on mine right now and want to check. X2, the pilot circuit got gummed up after the last go round.

[Jedz123]

Love too... But I sold my B-12 to Lurch awhile back.

Currently looking into doing a partial trade and my coin for HJFisk's ZRX 1100 but if that falls through I'll be bringing my monies to someone with a B-12...
Then I could post some pics.

[Homie]

V&H slip on, orig air box & clean filter, don't know about carb jetting.

I had a '98 B12 for a while and I know exactly what you are talking about. It too would "surge" ever so slightly when the throttle was held steady during highway cruising. The induction and exhaust system on mine was completely stock. As they came from the factory the bikes were jetted boderline lean. With the V&H slip-on I imagine your's is a bit more leaner than stock and that is showing up in the steady state "surge" and occasional "burble" while cruising. Bump the jetting up a notch and I would say the problem will be resolved.