Hi There! From what you described it might be running on one cylinder at times. There can be many reasons for this and certainly if the bike sat for a while a dirty carb or fuel system might be one. When you put gas in it it may have stirred up some nastiness in the tank and washed it into the carbs. This is just speculation I guess, but it is consistent with what your local mechanic said.
Cost? Depends on the shop and it depends on the bike. Some bikes are easy and take less than an hour. I've never worked on your model so it's hard to say. Some can be quite a lot of work.
That said if you want to do some basic troubleshooting here are some things you can try:
From cold, start the bike. Monitor each exhaust header temperature - either with your hand or a good thermometer. Do they both heat up relatively the same?
Do you have access to a spark tester or timing light? Clip one on each plug wire (or try one and them move it to another..) Start the bike and see if it lights up. Is it similar on each cylinder, or is one darker?
The bad smell in your garage might be unburnt fuel or rich mixture, second only to the smell of hot rubber and fresh air!
Cost? Depends on the shop and it depends on the bike. Some bikes are easy and take less than an hour. I've never worked on your model so it's hard to say. Some can be quite a lot of work.
That said if you want to do some basic troubleshooting here are some things you can try:
From cold, start the bike. Monitor each exhaust header temperature - either with your hand or a good thermometer. Do they both heat up relatively the same?
Do you have access to a spark tester or timing light? Clip one on each plug wire (or try one and them move it to another..) Start the bike and see if it lights up. Is it similar on each cylinder, or is one darker?
The bad smell in your garage might be unburnt fuel or rich mixture, second only to the smell of hot rubber and fresh air!
