(26-08-25, 05:26 PM)vitman Wrote: Hi everyone. I’ve recently become a happy owner of a 2005 FZS1000. The bike is awesome, and I’d like to improve it further. Unfortunately, when I went to service the EXUP system, I discovered that the valve had been removed and the muffler welded. In Estonia and neighboring countries, it’s very difficult to find a header with this valve.
So I’ve got a question before I start. How badly does the absence of the EXUP system REALLY affect low-end performance? I ride about 80% in the city, and I’d really like the engine to pull well at low RPM right away.
I found a company on eBay that makes jet kits for the Fazer and other bikes as well. They’ve sold over 100k kits and have around 40,000 reviews. From what I understand, they select the kit based on the bike’s setup.
So here’s my main question: if I order a kit for a completely stock bike but with the EXUP disabled, what will come out of it? Will everything run fine, or is it better to restore the EXUP by any means?
Thanks
Jet KIT 6 SIGMA
Hi, and welcome to the forums, I'm glad your enjoying your Fazer. Under the "Important Threads" section you will see a FAQ for the Gen1 Fazer 1000 which I'd encourage you to read as a new owner as it has lots of useful information.
To answer your questions with the EXUP valve missing your bike is not going to be ideal for town use as it will be missing the low down torque that the EXUP system is designed to provide so will instead be quite flat at low revs and then take off at higher revs. Unfortunately the only way to resolve this is to restore the EXUP system which as you say can be difficult / expensive to source. There are no jet kits specifically for a FZS1000 without the EXUP and the only jet kit likely to be recommended on these forums is the Ivan's kit which is mentioned in the FAQ but even this won't restore the low down pull that the EXUP valve provides.
If replacing the EXUP isn't going to be possible but you still want to improve the bike, then looking at the rear suspension would be a good place to start, especially if the shock is still the original one, as replacing or refurbishing it will make a noticeable improvement on the handling.