I am rideing a 2007 RS w? 12000 miles. I have had this issue on my bike from day one. I have had my bike back to the dealer 50+ times. Two weeks ago Yahama agreed to replace the fuel pump, installed a new factory card, rejetted the carb, tuned the bike up and changed the oil free of charge becaue of the pukeing issue. I rode the Bike to Blues bikes and BBQ last week it dumped again after a short 1 mile ride down dixen street 65 degrees out. I took my bike to the local Yahama dealer that has one of the top 5 rated mechanics in the country at the recamendation of the corprate guys at the event and was told the only true fix is to install fuel injection. At the same time this tech explained why this happes. Due to the amount of ethonal in the fuel it has a lower boiling point and when the eng or fuel gets hot it expand and pushes out of the carb and on to the hot exhaust. As ScottW has posted this tech confermed that heat shild tape on the carb and on the fuel line helps but is to a full fix as I have had this done and at 79 degrees back in kansas rode home from work, parked the bike for about 15min and it did it again. No hot stop and go trafic, NO extream heat out. At this point I think Yahama should be issuing a recall as this is a HUGE safty Issue as the fuel is hitting the hot exhaust and as indicated by ScottW can and has caused bikes to catch fire. I am a witness to this as I had all but flames comming off my bike in august in OK when it was 105deg out wit a heat index close to 115deg. I have seen it. When I ride W/ my friends they now refer to my bike as the CHAWAWA as it PISSES fuel all the time. I ask every one with this problem to pleaase call Yahama at 1-714-761-7300 ext 7484 and let TY know you to are having this problem. Just maybe we can all get Yahama to come up with a true fix.
When you insulate the fuel system the way i suggest with the same exact 2,000 deg insulating tape i use which are key factors doing that stops the puking at any temp,period.
Again,my bike puked fuel im 55-60 deg temps 4 of 5 times it was shut down without any involvement of elec f-pump at all & post doing the insulating fix i came up with in 2009 on my 06 R* doing it the way i suggest & also using the same exact insulating product i suggest my bike didnt puke fuel in 100-+ deg temps this past summer.
I got same resuilts when i did my fix on my friends 05 silverado ,no more puke even in 100 deg temps for him too.
A few other RSC memebrs tried my fix and they also had the same good results with no more carb puke too.
The problem is when some people insualte the fuel system they dont realize they need to use a high quality space age type insulating material due to extreem heate generated by the lrg aircooled R* v-twein motor so in that case the heat isnt properly dealt with hence carb puke isnt completly eliminated.
Then add to that most people only insulate the fuel line inbetween the cyls using on 1 layer of inferior insulating material and then say it doesnt work all the time,even when they also insualte the float bowl too.
Collectively not using an insulating material that can handle heat,no using dbl layers on fue line inbetween the cyls and on flaot bowl too,and not insualting the f-pump-fuel filter & associated fuel lines to reduce fuel temp entering fuel line inbetween cyls not getting that done the way i suggest with the same material i use will not get you consistant no puke results likle i got in 100+ deg HHH conditions ,end of story.
Last time,when you have a stock R* still running the lrg stock air cleaner and elec f-pump & fuel filter in stock location all of which sig reduce airflow/reduce cooling efficiency causing hi temps required to overheat the fuel in some cases litterally boiling fuel out of the float bowl that if in that case you use the proper 2,000 deg insulating material like i used ,use a dbl (if not tripple) layer of it on the metal fuel line inbetween the cyls using hd hi temp tie wraps to ensure it stays put,wrap 1 layer around elec f-pump-fuel filter -& fuel lines associated with them as to reduce fuel temps in those items not preheating fuel prior to fuel entering the metal fuel linel inbetween cyls,then also put a dbl layer of insulating material on all sides of float bowl,and then 1 layer on remaining portions of carb you can get attach more insualtion to without interfearing with proper throttle cable operation thats when the carb puke will be stopped for good.
You back off insualting a couple things not insulating everything i suggest along with maybe using an inferior insulating materal and the carb puke will likley be improved/reduced in frequency but it will not be totaslly eliminated like when doiong it my way with the insulating mterial i suggest.
Look at my carb puke fix like a cooking rcp,if you dont use the same ingredients at same amounts cooked at same approx temp & time the rcp/food dish wont come out tasting /looking the same each time if you leave something out like not insulating the complete fuel system like i did or use inferior ingredients etc the end result will not be the same/will not be as good,see what i am getting at?
Thats very likely why when the experienced Yami
tech you speak of insualted the R* it didnt stop it from puking all the time,just reduced the frequency of carb puke some depending on outside temp.
,when people remove/relocate f-pump and fuel filter doing just that increases cooling in between cyls enough in some cases to stop carb puke or to at least reduce its frequency to puking only hot to extreemly hot temps only.
Then add to that replacing the lrg stock aircleraner with a smaller aftermarket aircleaner increasing cooling even more inbetween cyls now being open at both left & right sides for much better airflow/cooling inbetween the cyls and esp at carb and carb puke should be history at that point with on insualting of fuel system required at all.