Start-Up / Loss of Power Problems - HELP!!!

[varatiki]

Hi. I'm new to the forum, and am in some need of help with a few issues that I have with my wife's 1999 GZ 250. Not entirely sure if there is any overlap between the two main issues aside from loss of compression... but I'll get into that shortly after I give you as much background as possible. I’ll apologize in advance for the length of this post, but I figure the more information, the better.

About a year ago I picked up this bike used with a branded title as a beginner bike for my wife. Although I knew that it was considered totaled previously, it checked out mechanically after inspecting it and running it around a bit. I bought it in Portland, then drove it 300 miles up to the Seattle area in the rain without any problems aside from running out of gas a few miles from home (mental note, no low-fuel warning light like my bike). Since then it has run well until the beginning of the summer.

I think the awareness of problems started with the bike dying occasional when it came to a stop. This has since gone away as far as I know. I wasn't there at the time, but it sounded to me like it slowly sputtered to a stop, and then would take some effort to get started again. The second problem that got me to do some work on it happens when riding at freeway speeds. At 60-70mph, it seems to lose fuel to the engine and cut back quite a bit, almost as if there was a fuel governor on the bike. After the speed drops a bit (or perhaps the time passing is the remedy) it catches again most of the time and can carry on. Once or twice the loss of power occurred at 30-35mph. My wife says that she can feel it coming on, but I don't know whether she was simply cruising or accelerating when it happens. My guess for the cause of this is the fact that the previous owner chopped off a good chunk of the exhaust pipe to make it "sound" better... but is killing the back compression. This power loss issue still exists (I haven't replaced the exhaust yet - and will go back to OEM).

However, as a result of this, I tooled around on the bike a bit. In July with about 12,500 miles on the bike, I changed the oil and filter, replaced the fuel line, inspected the brakes, cleaned the air filter, and tightened, cleaned, and lubed the chain. It seemed like this fixed the problem initially but found later that it still exists. Next round of repairs in late August included completely draining the fuel tank to get rid of any water in the fuel (because the problem seemed to only happen when the fuel tank was about a third full or less). FYI, the timing was horrible on this because the tank was near full when I did it. YET, when done, I couldn’t see any signs of water in the fuel at all (I emptied it into a large pan). Just to finish the job though, I added SeaFoam to a new tank of gas. Since then I have installed a new battery (that I fully charged for 8-10 hours or whatever was specified on the trickle charger that I used) and replaced the spark plug. The bike seems to run better, but same problem on the freeway. Again, my guess Is that a new exhaust pipe might fix this. Your thoughts?

Now, as of tonight, the bike won’t start on its own. The bike wasn’t driven for 2 months, but was started and ran for at least 15 minutes every 7-10 days or so. I last ran it 5 days ago after having to jump start it because my wife couldn’t get it to start and drained the battery. Slaughter me now, but I didn’t know that jumping it with the car on is a bad idea… and I’ve done this a few times in the past because it failed to start before draining the battery. Anyway, it’s been dipping down into the 30-40 degree range at night, but was 52 degrees out when it didn’t start tonight. Pre-starting it, I set the fuel to “PRI”, fully opened the choke, and then hit the start button. I couldn’t get it to start at all. Usually starting the bike takes a bit of an effort and the starter(?) has to crank over quite a bit before slightly catching, then dying. Repeat, then catches a bit more… dies. Repeat while cranking on the throttle a bit, then it possibly catches and runs this time or the next. That’s normal for the bike (or with whatever problem causes it not to fire up right away – if this isn’t normal I need help here too). After reading through the forum, I saw that somebody describes the starter as making a “whirring” sound. Not the case here. If it’s meant to be a “whir” this bike emits a much slower turn as it “normally” starts. Like counting: 1.. 2.. 3.. 4.. 5.. In comparison, tonight it sounded like 1…………… 2…………… 3……………… 4, THEN sounded as if the starter had turned (on each count, it sounded like it tried, but didn’t quite get there). I didn’t check to see if the headlight completely dimmed when I was trying to start it, but the bike didn’t run out of juice as if the battery was dead before I gave up. The green ignition light came back full every time and I was able to repeat the process multiple times. I tried setting the fuel to both “On” and “PRI”, and yielded the same result. It definitely felt different from when the battery has died previously. I gave up on the bike starting itself, so I tried jumping it with the car (again… oops because I had the car on). Once hooked up to the car, it fired right up. I then ran it for probably 10-15 minutes before shutting it off. After turning it off I waited about a minute, then tried starting it on its own without being hooked up to the car. Same exact problem starting it that I had at the beginning of tonight.

Obviously I am trying to avoid taking it to a shop, so any help would be much appreciated!!! Should I try fully charging the battery with the trickle charger again? Otherwise where should I start? I don’t yet have a voltage meter so I haven’t checked the battery or the electrical system (will have to look up how to do this or re-read a few posts on here to learn how to do this).

THANK YOU!