i Recently purchased a 99 busa, it sat for roughly 3 years. i could smell the bad gas as i started it, it ran for awhile then cut off, ive changed plugs clean lines clean tank cleaned injectors and bike still want start. i was told i may need ecu. has anyone ran into these issues? bike will start shooting ethanol into intake


I don’t think it’s the ECU, sounds fuel system related, fuel pump, fuel filter clogged something along those lines. Also make sure you didn’t foul the new plugs. Can you hear the pump prime with key on?

Kiwi Rider

You need to check fuel pressure at the pump outlet, and fuel delivery at the injectors.
I also have a 99 model, they have an external pump and are known for clogging the mesh screen and also can vapor lock as well if the pump's insulation is missing or too thin, pump overheats and the fuel cavitates causing problems.
ECU issues are very very rare.
As others have said, search the forum.

Mr Brown

For that model I believe the fuel filter is in the tank, will have to pull the tank, flip it over and pull the assembly to check the filter. If it is clogged or deteriorated that could cause your issue. Would at least look at it before I purchased another ECU.
I was thinking 99 had an external fuel pump.
99 and 00 models have external pumps in a really bad location. Design changes in 01 rectified that, fuel pump has been in tank ever since.


Donating Member
my bike sat for a while and the bad gas wrecked havoc inside the tank the cable to fuel pump actually broke off and it only sat for 7 months. take the pump out for inspection the yellow gel covering the fuel system and the condition of wires may give you chills

Kiwi Rider

I love all those emergency threads where people (who don't even introduce themself) need immediate help and never update us on whether it was helpful/ fixed or not...!
Yeah, I reckon word must’ve got around that there’s a few tech savvy dudes on this forum and they come looking for a second opinion or even a helping hand for free.
They are the sort that don’t want to join in and be part of the community here.
It’s cool to offer assistance to strangers though.... who cares if they never return.

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