HELP !!!!! totally stuck

[renegade]

I wonder if anyone has any ideas on a problem i have with my Xjr 1300sp,Ive had the carbs off and cleaned due to fuel filling the airbox and leaking everywhere ,put new air filter in new plugs ,oil and filter changed,new throttle cables fitted ,had new battery about 6 months ago,carbs refitted ,pilot jets done to correct settings etc.

Now bike starts pops a bit for a few seconds then sounds and runs great until ..............the engine gets warm /hot then the revs drop and it cuts out. I'm not overley mechanicly minded so looked on line and things pointed to the coils might break down when hot,so i have fitted some new( second hand) coils today exactly the same .

I am now at the point of pulling my non existing hair out.

Any ideas PLEASE >>

[Lee]

This is an unusual fault but the fact that you’ve had a fuel leak reminds me of a similar fault I had.

Dip your oil, or sniff at the oil fill up hole. Does it smell of petrol ?

A diaphragm failure on the fuel tank, causes fuel to flow the wrong way along the vacuum hose.
Fuel flows back to the manifold and slowly seeps through your carbs and in my case, eventually into the bore.

One of 2 things happen,
Fuel will end up all over the floor, or it will seep through the bore and fill your crank cases with petrol.

With the diaphpragm not working correctly, the bike may start for short periods amd then cut out after10-30 seconds.
I had it happen on a blackbird... I opened the oil filler plug and petrol came horsing out !

If when pulling the vacuum hose off the tank, and it’s full of fuel, then that’s a sure sign of diaphragm failure (provided you’ve got fuel in the tank)
Failing this, just check your vacuum hose for perishing or splits.
Both of which will cause your bike to cut out after a short period of running.

[renegade]

Thanks Lee,a few months back i did have the problem of petrol in oil also flooding the airbox and pissing out all over the place,i took the carbs off and a friend who knows carbs found that everything was like brand new except one emulssion tube was blocked ,this was cleaned and carbs put back on,while this was taking place i put a new filter kit (diaphram ) included into the fuel cock along with all the other parts prieviously mentioned ,this last week started leaking again and i put another kit in and noticed the spring wasnt strong enough to push the plunger seal in tight enough ,so sorted this out.

Sunday took bike out for about 15mins to try it ,was going great,last night i took it for a longer run about 40 mins again to try it,was going brilliant until i got back home where the revs died and it cut out again strong smell of petrol no leaks sounds like only running on two cylinders ,started this morning runs ok gets warm cuts out .

Anyone hearing a loud explosion dont worry its just me throwing a match on the bloody bike !!!!!!!!!