scorpion end can

[sonic242]

Hi All

My name is Dave and I based in Scotland UK. I have a 2001Suzuki gsx750f or 750 katana for you guys over the pond. I have fitted ascorpion end can to my bike and it feels very flat in the mid-range. I had the bike on the dyno and they told me thatthe bike is running rich on main and lean on needles. I don’t want to spend the £300 ($500) + ongetting them to set the carbs up. Cananyone give me some advice on what to do next?


Thanks Dave

[92xjunker]

this is a guide to use for tuning reference, also you can turn the a/f mixture screws up a little. being that you have a uk model your settings may be different.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

[sonic242]

Thanks.

[sonic242]

I have been reading a bit about carbs setup and have found some conflicting information which someone with more knowledge than me could answer. The pilot screws on the back of the carbs I always thought that the further out you screw them the richer the mixture is this correct? I was reading mikuni 101 carbs theory and it seam to imply the opposite unless I am reading it wrong.

[Kreylyn]

I have been reading a bit about carbs setup and have found some conflicting information which someone with more knowledge than me could answer. The pilot screws on the back of the carbs I always thought that the further out you screw them the richer the mixture is this correct? I was reading mikuni 101 carbs theory and it seam to imply the opposite unless I am reading it wrong.

It all depends on where the screws are located.

On the katana carbs for example, they are on the engine side. So when you adjust them you are adjusting fuel.

On other carbs they are on the air box side. In those cases your adjusting air.

So location tells you what your adjusting, and it's always more of that when your turning them out from seated.

Krey

[edromero]

Hi All

My name is Dave and I based in Scotland UK. I have a 2001Suzuki gsx750f or 750 katana for you guys over the pond. I have fitted ascorpion end can to my bike and it feels very flat in the mid-range. I had the bike on the dyno and they told me thatthe bike is running rich on main and lean on needles. I don’t want to spend the £300 ($500) + ongetting them to set the carbs up. Cananyone give me some advice on what to do next?


Thanks Dave

you don't have a high-flow air filter do you? If so, replace with stock filter.

I recently had this same problem between 4000-6500 or so (different pipe though) and with the guys' help on this forum I got it sorted out by adjusting the needle heights. it's very easy to do, took me 10 minutes, and you don't have to take the carbs off the bike.

1) remove tank
2) open black top of carbs (2 screws each)
3) remove diaphragm
4) remove needle
5) move retaining clip down 1 notch on each carb needle (raising needle to make richer)
6) replace everything

I am not a mechanical person, but after seeing how easy it is to do this adjustment, you'd be angry at yourself for paying someone 300 quid to do it for you.

[sonic242]

Thanks I have adjusted the needles but been to busy to go out for run the bike is 2001 so I think that out should mean more fuel. When revving the bike hard in neutral it does miss and will not rev to the red line. At the moment it idles ruff too. I will take it out for blast and report back.

[sonic242]

Ok progress I was out on the bike today and the flatness in the mid range has gone. However it feel like running lean on small throttle opens at low rpms. I have the air screws set 2 turns out on 1 and 4 and 1.5 turns out on 2 and 3 as per the manual. I am thinking of going to 2 turn all round?


Cheers Dave

[edromero]

Ok progress I was out on the bike today and the flatness in the mid range has gone. However it feel like running lean on small throttle opens at low rpms. I have the air screws set 2 turns out on 1 and 4 and 1.5 turns out on 2 and 3 as per the manual. I am thinking of going to 2 turn all round?


Cheers Dave

the guys on this site will probably tell you that 2.5 turns for all carbs is preferred, but there may be some difference for overseas models. i'll defer to their advice once they come along

[Kreylyn]

I'd just suggest using the drop down method and tune them on the bike. The engine will tell you exactly what each one needs to be set at that way.

(carb drop down method) google that for details on procedure.

Krey