I don't understand

[JHONNY_ICE_420]

I find it strange that there is very little info in the EXHAUST & MOD section on ACTUAL POWER MODS. There seems to be a ton of info on how to mount xx pipe on xx bike, but I assumed that this section would be about power produced by a certain pipe vs. another (yosh vs. two brothers vs v&h vs stock)
SO I have a question on power-- I have a 89 kat 750 w/a full yoshi system. I would like to replace the worn emulsion tubes in the carbs, get the right needles, and put pod filters on the carbs, but how much jetting needs changed? just the mains?
I would also like to take the baffle out of the exhaust if it flows better, not just for noise. do I need to rejet for the exhaust mod? Do I need a timing advancer to bring out everything this thing has? Any other ideas for cheap power?

[RoadRacer61]

Ignition advancers are fairly cheap and easy to do and seem to make a noticeable difference. If the bike already has a full Yosh system on it, chances are it's already been jetted, but don't bank on it. When you pull the carbs apart to do the tubes, look at the jets vs the factory numbers and see what you have.

There's a lot of people on here that will discourage the use of pods, and there's a lot of people on here that like them. I run them, I like them, but that's me.

Depending on the Yosh you're running, it might be a straight through design to begin with. If that's the case, you prolly want to leave the packing in it. It's not going to do anything but make it louder. But then again, louder is faster right? If it's acceleration you're looking for and not top end, an easy way to achieve a harder acceleration is to either drop a tooth off the front sprocket or raise the rear by two teeth. I wouldn't suggest going any more than that because you lose your drivability on the interstate and such.

That's just my two cents....

[md86]

Pay for the dyno time and pipes , and you can put any exhaust you want on my bike to test them back to back ....

[Kreylyn]

A properly choosen exhaust isn't going to make a noticeable difference on power for the Katana overall. Tweaking your flow will put the power band curve higher or lower depending on what you want as a best case senario. This is why there just are not many "X brand is better than Y brand".... the differences are negligable, and not everyone who rides is going for the most power in the same range.

Some want more take off... some want higher top speed.

For the cost/time vs improvements that are worth it... most choose...

Any after market exhaust prpperly designed for the CC on the bike.
stage 1 jet kit
advancer
adjusted counts on the sprockets.

And that would be why you don't see alot of focus on the exhuast alone for power mods.

Edit to add... the primary reason for this is there are very little things you can do to change the engine (unlike many cars) that would require a need for a change in the exhaust.

Krey

[JHONNY_ICE_420]

Good replies, good explanations. I want less of a flat powerband. my bike just gets a little more as it goes up in rpm. It starts to get good around 5k and just gets stronger as it gets to 10.5k, but it's not very entertaining. I grew up on 2-srtokes and I would LOVE a lightswitch style power spread like "It's dead untill 8500 then OH MY GOD it comes on so strong!"
Any suggestions?
BTW IM LOOKING FOR A TRANS THAT WILL FIT MY 89 KAT 750

[Kreylyn]

Good replies, good explanations. I want less of a flat powerband. my bike just gets a little more as it goes up in rpm. It starts to get good around 5k and just gets stronger as it gets to 10.5k, but it's not very entertaining. I grew up on 2-srtokes and I would LOVE a lightswitch style power spread like "It's dead untill 8500 then OH MY GOD it comes on so strong!"
Any suggestions?
BTW IM LOOKING FOR A TRANS THAT WILL FIT MY 89 KAT 750

If you want something for general street riding (still not much of an issue to putt around town with out having to use high rmps on take off) then just do the list I mentioned.

If your needing something more race responsive (high rmps most of the time, no power low rmps) then your probably looking at a stage 3 jet kit. Warning... it literally is almost unrideable on the streets with a stage 3... well tuned, mine wanted to bog down (flood out) under 6k for any take off. Riding around town was nearly impossible to do without flagging every policeman down and saying "pull me over please!". But when it hit 8.5k... well lets just say you better make sure your helmet is strapped on...

Krey

[scottynoface]

Good replies, good explanations. I want less of a flat powerband. my bike just gets a little more as it goes up in rpm. It starts to get good around 5k and just gets stronger as it gets to 10.5k, but it's not very entertaining. I grew up on 2-srtokes and I would LOVE a lightswitch style power spread like "It's dead untill 8500 then OH MY GOD it comes on so strong!"
Any suggestions?
BTW IM LOOKING FOR A TRANS THAT WILL FIT MY 89 KAT 750

You need either a GSXR engine swap, or to go out and buy a GSXR. The Katana isn't a race bike, so it doesn't come with that huge wallop up top. It's still there, just not as ridiculous.

[CenCalKat]

Or swap in some 89 gsxr 750 cams with the jet kit and advancer. then go to the dyno.