What Warchild and the others have said. I don't know why I have such shitty karma, but after NEVER having a flat on a motorcycle tire, I have gotten a flat on EVERY one of the 5 rear tires I have had on my FJR. The last was 125 miles after I mounted a new rear Avon. Shit!
So, I am saying I have a bit of experience, and here's my recommendations:
I would continue using it, but get it PROPERLY repaired. By that, I mean finding a shop to do it if you can, and having them install a
proper plug/patch from the inside of the tire. This procedure also entails drilling out the injury on the tire, and is the only method of repairing a tire that the tire manufacturers accept. Even then you lose your speed rating, but I don't worry about that too much. I think that's due to liability concerns. Now this cost's me about $45 to have done, so if the tire is near the end of its life, just replace it, or ride a while with a do it yourself patch, which I will get to later.
Here is what the proper repair looks like on my stock rear Metzler:
I was going to buy one of these totally awsome Tech Uni-Seal tire repair kits, but the cheapest I could find one for was like $170.
And some items, like the rubber cement have an expiration date. So scratch that plan. I had 3 of my 5 flats repaired in this manner by my local Yammie shop.
Do-it-yourself tire repair kits.
First of all, I don't recommend riding a tire repaired with a do-it-yourself kit for long distances unless you can't avoid it. It may be ok, and sounds like some above have had no problems, but thats more than my personal level of safety thinks is prudent. Do note however that on a recent flat during the Cal24 rally, I rode another 1500 miles on a do-it-yourself kit until I got home and replaced the very worn tire.
Stop-n-go plugger - I used to recommend this kit, but no longer do. Save your money. I have had mixed results, but on two occasions, the kit would did not hold the repair past a few miles. I did make several repairs with this kit that held for several hundred miles until I had the shop make a proper repair, but the approximate 60-75% success rate I have personally encountered is not acceptable to me. Even the kits warnings say not to ride at high speeds past 50 miles I think, and that it should be considered a
temporary repair.
The mushroom plug the Stop-n-go plugger kit uses is soft. Too soft IMHO. Someone once told me the kit was designed to repair atv/golfcart tires and that is why the plug is so soft. It was designed for a different type of application. You want to know what I think? Well, I am going to tell you anyways. I think that with the soft Stop-n-go mushroom plug, the sharp steel or nylong belts of the tire where it was punctured sever the plug. No bueno.
Anyways, I now recommend the sticky worm type do-it-yourself type repair kit that so many others swear by. Compared to the Stop-n-go, it is cheaper, weighs less, and takes less space. I got mine at Wallyworld, though I will look for a specific and compact m/c kit in the future. I have only used it once so far, but I rode it 1500 miles - as I mentioned earlier. And this was after initially using my Stop-n-go kit which deflated after 45 miles, while traveling at 70mph. It is relatively simple to use, and is self-vulcanizing as Warchild mentioned above. I have now ditched my Stop-n-go kit.
So there you go. My only hope is that you have better luck than I when it comes to FFTs (F***ing Flat Tires). At least I have never had a flat front tire, and most of my flats I encountered with the bike parked in the garage.