i need help quick the season is almost over

[squid]

when bike is warm and at operating temperature, at a stop the bike will stall and not restart, usally killing the battery, once it is boosted it runs fine. the other problem is i have a vacuum hose from the top of the carb air horn and i dont know were its home is could this be related??
so any suggestions would be great.

[Lucky]

The first one is easy, Assuming the hose your speaking of is comming out of the right side of the front airhorn (top) it goes to the airbox flapper.  If you don't have an airbox flapper, I wouldn't worry about it causing a big problem, just cap it off so that you don't have an unfiltered source of air entering the carbs.

For the stalling problem, I'm guessing your not losing the electrical system when it stalls, (headlight is still on, etc)does it happen as soon as the choke is off, or fully warmed up?  your carbs might be out of synq, needing a rich mixture to run at all, and as the bike warms up, it leans out, and once the bike is running low rpms (carb is using idle (pilot) circut), it stalls out.

other things to check would be Pilot adjustment, a vacuum leak, & be sure to check the YICS, fuel pump & petcock for leaks too.

other things that come to mind are fuel starvation (do you have a filter installed, is it clogged? is the petcock screen clogged?) or Ignition failure (do you have a spark when your trying to start it? could be ignition switch (nor real common, but it happens) pickup coils (rare, but possable) or just a bad charging system (on it's way out, charges at only at a higher rpm, or not at all.  run the Electrex flow chart.

I hope this gives you places to start looking, if you can test some of these theorys, & let us know the results, then we could narrow it down some more.
--Lucky

[squid]

when this happens the headlights etc are ok. it appears that there is no spark, the petcok screen is clean,and i cleaned the carbs as soon as i got the engine, the yics box is new and not cracked, and this problem only seems to happen when fully warm. it has lots of cranking power and before it stalls it almost feels like i lost spark  ???

[QBS]

Get a phillips head screw driver and go for a ride with the petcock in the prime position.  The next time you experiance your problem, immediatly put the bike on center stand and open each of the carb drain screws and watch for fuel flow out of the overflow drain hose.  No flow means that your fuel tank isn't venting and what you are experiancing is fuel starvation.

Another variation on this diagnosis technique would be to do the same test at home with the bike cold.  Remember, the petcock must be in the prime position for these checks to render valid data.  Cheers.

[squid]

ok, so now i got this demon to occur in the shop, at operatin temperature it will stumble and die, cranking power good, fuel out of the carbs....good, spark......no go, so could this mean the ic box has gone south???once it cools down it is a okuntill hot again

[Lucky]

Did you check the charging system?

[Rick G]

I don't believe its the TCI box , get a load test on the battery and check the charging system using Eletrx's chart! Don't assume that the YIKS bos is ok , pull it off and  suck on each hose in turn,  if you can pull air from either it needs some work. Also  inspect all the  vacuum hoses  for rot ,cracked ends or looseness on the fittings.

[squid]

I finally got that demon out of my life, i found the problem (well it fixed it cause it aint doin it nomore ;D) this may be hard to swallow but hey the bike ran long and hard on sunday and never stalled and always started, it appears that the flasher had fallen out of its retainer and was hangin upside down, so when i put the new engine in i decided to shampoo it and polish it up, what had happened is that the flasher fillled up with water and from as far as i can tell, it either grounded out sent a feedback signal to the magic box. so once dried out and cleaned up  everthing o.k.  ;D
thanks for the advise, only a few short week of riding left and now i can finally enjoy it 8)