It's due to heat buildup,
I fought this for 25K miles. Fireman turned me onto this bolt on, I forgot PN but like $42 Autozone it's a K&N air cleaner, as pictured RC 1980 K&N??? Paul correct me if I am wrong.

If you don't have a BAK now you will need to re jet. So Price of Jet kit and time.
And, shave off the pump, run line to carb, and do the Suzuki PN 2.5 13370-08F50 Float valve ($30)and no more puke!
(How to on this is in Tech Section, going pumpless. For some reason it's not under Carbs.)
I have been in Very high temps and extended riding and shutting on and off every 10 min all day long and no flooding or puking after doing this.

And people swear the &N does not FOD out in rain I haven't pushed it I made a caver out of a Baby Wipes container.

I stopped at every dealer in the country I passed, none have a cure, they know about it but Yami cured it with FI in 08 and left the rest of us out in the cold. Just lose the pump!

I have been turning off the gas at the tank when I shut off the bike, I ride out here around Palm Springs in 104+ heat and have no problem so far.
I am running everything stock except for the V&H Long shots exhaust.

i have a 07 1700 also,mine used to do that and i re-set my float level as per instructions from the clinic........no more problems

bullfrogsierra wrote:
i have a 07 1700 also,mine used to do that and i re-set my float level as per instructions from the clinic........no more problems

Thats what I've been telling everyone. Those shutting the petcock are only stopping the symptom and not stopping the problem.

I shut the gas off because I have tried all the fixes,and still occaissionally get a puke. The float is adjusted, the bike is jetted the fuel pump works as it should, the fuel line is shielded and not in contact with the cylinders, the vent line is clear, the bike has a BAK and still once in a while she will spit up. Something sticks somewhere and the pump runs continuously and fuel runs down out of the carb down the side of the engine and onto the ground. If you shut it down and wait a minute she starts up just like nothing happened. I have just learned to live with it and love my scoot in spite of her peculiarities.

Crusierbob wrote:
I shut the gas off because I have tried all the fixes,and still occaissionally get a puke. The float is adjusted,


Where is the level of the float adjustment? Above or below the mating surface? Maybe some dirt in the needle valve and not shutting all the way? Ok, carb is jetted, is it jetted correctly?, too lean will also add to the problem since it will cause excessive heat, then add heat of outside ambient temps.

My float was adjusted all over the map, every suggestion here and then some, it still did it, But if you DIY it's a free try.

I have an 06 with 25,000 miles on it that I bought new. I have Cobra Speedsters, BAK, stock manifold, no AIS, at sea level, Main - Mikuni 170, needle 4th groove, Stock 35 pilot, PMS 2.5 turns out. I have run this configuration for over 22,000 miles, get 38 mpg city, 44 highway. I have changed plugs regularly at 8,000 miles and they are slightly ash gray to white, no erosion of the electrode, with some black on the inside of the threads indicating somewhat rich in idle circuit. She WOT's out perfectly so no lean. I have not put her on a Dyno, but from the way she runs the mix is pretty good. As for the float an 04 and up the level should be as I recall 1mm above the mating surface and that is where mine is. I have had the carb off at least twice to check the needle valve and it is clean. I have not experimented with lowering the float level, but that is probably the only thing I have not tried. Thanks for the help, but feel like I have pretty much tried it all short of replacing the fuel pump and pressure sensor. This is not a regular occurence it happens perhaps 3-4 times per summer so not such a problem. I am sure it related to heating of the carb and expansion of fuel...I have thought about shielding the carb and seeing if it solves the problem. You will see my name on puking strings for the last 2-3 years, but always open to new ideas.

Crusierbob wrote:
As for the float an 04 and up the level should be as I recall 1mm above the mating surface

Forget what the book says, bring it down to the 1600. mating surface or 1mm below. Not one person can explain why the 1700 carb has it set that high compared to the 1600 carb. I also don't know anyone with a 1700 carb set to lower float level having issues. Also a float level too high can also cause a loss of mpg's. I don't know why they made the 1700 carb to be so much richer, not only in float level, but main jet, and air bleed jets too. 3 changes to carb they made and all 3 make for richer conditions.

Since that is the only thing you have not done, float at or below mating surface, try it. To me 3 or 4 times is still too much. I've, multiple times have been in 100 + degree, even at a snails pace and have yet to have gas overflow. Trust me, it is not a fuel pump issue.

I've been reading about this puking problem for a while and have seen many theories of what the problem is. I never had the problem until I jetted my carb and bumped the float. When I found that problem I fixed it with float hieght found here in the tech article. I didn't like the results of the jetting so I went back to the stock main jet size for a 07 1700 which is a 182.5 I have a speedstar BAK and still got a carb cough just off idle no matter what I did. so I put a 45 pilot in it set @ 2-1/4 turns on the screw and it runs perfect plugs are all light tan. don't know the mileage yet. Point being I know I'm not running hot from a lean condition. So I took some temp reading from the cyl heads with a infared thermometer. Temps are intake side of eng 205F, exhaust side bottom of jug 215F-220F, carb area 165F. After I returned to current carb jetting and float level the puking went away.
If someone that has the puking problem and has rejetted could take some temp readings in the same area as I did, we could do some comparisons to see if it is heat that is doing it.