I have just bought an old 81 GSX750.
Bottom line give me more power and cool style at a cheap price!!!
More power in order of cost:
1) 4-1 exhaust. I personally like the look of a megaphone pipe on our older bikes, since it is correct for the period, but you can semi-easily add any can you like to the header you have by fabricating a new mid-pipe to suit the header outlet and your new canister inlet. Not free, but pretty cheap overall. Depending if you want lots of noise or not, you can use almost any current sportbike can. Stock canisters for GSXR's and Yamaha R's are available for a few $$ off E-bay and will flow more air than your 750 will ever need. They are light, high quality (unlike some aftermarket stuff I have seen) and quiet, which is good for keeping your neighbors happy...
2) Pod filters and rejet. Rejetting is not that hard, but it does take some experience and fiddling time. If you are not willing to spend a few afternoons tinkering, don't go there. I had my carbs apart 5 times (near as I can tell from my notes) for main jet and needle height changes before it was right. Took me a total of a several nights and one weekend tinkering in the garage to get it there. One thing to consider with pods - it is a snap to pull the carbs with pods installed and a serious PITA with the airbox in place. For that reason alone I switched to pods sooner than I had planned.
Really #1 and #2 go together. If you are only doing one of them, add the pipe and rejet with the air box. You can also remove only the back half of the air box and add a single large K&N filter in place of the stock one. That makes power in between the full box and pods, but is easier to rejet for.
3)Degree your cams. This really costs nothing but time and a set of slotted sprockets, but you need some mechanical experience and tools to get it done. The stock cam timing is notoriously inaccurate and you can easily find 5-8hp if your cams are way off from the factory. My intake cam lobe center was off by about 9 degrees as I got it and that is a world away from correct. Yours may be too. As a bonus, you can use different lobe center setting to tune the power to suit your riding style and preferences.
4) Cams. Now you are talking $$$, but you can gain significant power here.
5) Flatslide carbs. More $$$, but combined with cams, pipe and pods will add a major power boost. You can also use larger CV carbs from a newer GSXR or Bandit motor (all the oil cooled GSXR and Bandit motors share the same bore spacing and many parts with the 4 valve GS motors). You will have to rejet the CV's as well (I can't imagine they would work OK as they come) and for that you will be on your own in terms of the combination that will really work well. Could be easy, could be tricky, depending on your luck and which carbs you get.
As for chassis mods, again in increasing order of cost (roughly):
1) Progressive Suspension fork springs, new seals and oil. Your fork likely has not been rebuilt in years and could use freshening up. Set the static sag (bike weight, no rider) to 20mm (from forks fully extended) and the laden sag (bike + rider) to 35mm using internal spacers above the springs. Try about 15wt oil to start and you will feel a huge improvement over the stock springs and oil.
2) New shocks. Progressive Suspension are the best value and then there are Ikon, Ohlins and Penske in order of increasing price and performance. Set rear sag to 10mm static and 25mm laden. I got my Ikon's made +1" longer than stock to raise the back end for quicker steering and extra cornering clearance.
3) New brake pads and a caliper rebuild. The old ones are likely tired and need replacing anyway. This is a pretty cheap thing if you get some pads off E-bay (mine were $10USD for 2 pairs) and do the rebuild yourself. It is easy to do and you learn more about your new bike.
4) Braided stainless steel brake lines. Huge increase in feel and power over the mushy stock rubber lines.
5) New tires. Again, the old ones are probably shagged or hardened with age (or both) and could use replacement. I recommend Bridgestone BT-45's. Stick great, work well in the rain and wear like iron. I have about 5000km on mine and there is no wear noticeable yet on the rear tire. Hard to beat that...
Last, get a manual. No, make that GET A MANUAL. There are so many questions on this forum that are clearly answered in even a Haynes manual, that it should be mandatory to have the manual first. They only cost a few bucks and are priceless for maintaining and troubleshooting your bike. Considering the cost of ANYTHING done by a dealer, the manual will pay for itself the first time you solve a problem yourself instead of taking it to a shop.
Mark
