engine stuttering when hot - fuel press regulator?

lensflare

Registered
Hi,

i have a problem i can't fiz by myself on my '00 Busa...

every summer, a strange problem come back to nag me, when the weather is hot, and
i take a ride in the city, in the typiucal situation of low speed and high temperatures, the engine begins to have a strange behaviour:
at low rpm's, all is ok, but, if i want to drive hard and accellerate over 5000rpm the engine goes bad
and seems to have problems in revving fast.
expecially if i accellerate suddenly, opening full throttle, the engine stutters and stumble trying to
gain rpm's, it seems like someone has moved the rev limiter to 5000-6000 rpms.

i have noticed somewhat strange when this happens:

if i shut down the engine and turn again the key, when the check is going, the "zzzzzzz" sound of the fuel pump is
replaced by a STRANGE "BUBBLING" SOUND in the fuel tank, like someone is blowing in the tank with a straw...

i'm thinking that this problem could be caused by a faulty fuel pressure regulator, that, when hot,
become crazy and bypass the fuel in the tank.
in this scenario, at low RPM the fuel is enough, but when i accellerate hard, there is not enough fuel to keep engine running high.

naturally, in the cold days of the winter, this problem disappears completely.
it appears only in summer, when the weather is hot and particular road conditions (light stops, traffica etc.etc.)
make the engine compartment very HOT.

naturally, if i take the time, shut off the engine and wait for the engine to return cold,
when i start the engine, the problme disappears.... until next overheating...

anyone has experienced this kind of trouble?

are there some check i can do to fix it, or some indications from someone that has solved this problem?

thank you.
 

pbghost

Registered
this is pretty much the problem that I'm having too, same sounds & symptoms on my '00. stalled completely a few times this trip, no error lights. just approach 5k & it tries to stall, same if I do anything but ease on the throttle. not a good thing in traffic! please chime in before I start doing exploratory surgery
cool.gif
 

Supergank1

Registered
didn`t the 99 and 00`s have fuel pump /fuel pump screen problems? maybe check the fuel pressure when this happens, could be vaporlocking.
 

cw344707

Registered
i have a 2000 too and i have recently been having this same problem.only in the hot weather, after riding for a while. it will start to stutter in low rpms and then fine after that. but once this starts the bike will actually totally shut off and will not start back up until given time to cool down.i bought the bike about 4 months ago only happened recently.recently its been really hot in ohio and i havent been able to ride. i was going to get it basemapped to see if its running right with the powercommander because it has a boz brothers exaust. i also took out the sparkplugs and they were black so i replaced them a couple weeks ago and i thought that could have been it but then i got stuck on the road again yesterday. any help would be appreciated greatly
 
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