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!

[JWR]

If the battery is low on power, it will not start.
The engine will turn over, but not fast enough.

I can not help you on the running problems, I have never had any issue with mine.


Jerry

[alantf]

I know you've drained the tank, but when you said that you'd run out of fuel, it set me thinking. The gz has a reserve of sorts, so you should have been able to keep going. Attached to the petcock (inside the tank) is a short pipe. In "run" fuel flows into the top of the pipe, until it drops enough to be level with the top of the pipe, when no more fuel will flow down it. Switching to "reserve" lets you use the fuel that is sitting at the bottom of the tank, below the top of the pipe. This is also where the gunge sits, waiting, so you could have got some "bigger" gunge in the carb than the carb cleaner could shift. Also, it's not unknown for the pipe to fall off, so that you're ALWAYS using the fuel from the bottom of the tank, & you have, in effect, no "reserve". BTW don't forget that the LONG side of the petcock lever points to whichever setting you want.

You may well have an electrical problem (battery?) but it also seems like you may have a fuel problem too. Best of luck. :2tup:

[Easy Rider]

Originally Posted by alantf

You may well have an electrical problem (battery?) but it also seems like you may have a fuel problem too. Best of luck. :2tup:

:plus1:

Some thoughts:
Your (main) starting problem is the weak battery. If you let it get TOO low and stay there TOO long......you can kill it. So, yes, by all means, charge it up good as a starting point. Sounds like you might want to invest in a Battery Tender or similar "maintainer" (which is different than a plain charger) if the bike will sit un-ridden for more than a few days at a time.

Starting it and letting it run every few days is NOT a good practice; one reason being that it will not sufficiently recharge the battery at idle.

Unless it is EXTREMELY cold....like below 30F, starting usually works better with 1/2 to 3/4 choke. Full choke (closed is the term) should only be applied for a couple of strokes of the engine......then opened a bit.

When you drained the tank, did you also drain the float bowl ?? If not, you probably should.

If you don't know the age of the air filter, I'd advise a new one....even though they are rather expensive.....they can become clogged and you can't really tell it. NOTE: it works backward from what you would expect and the dirt actually accumulates INSIDE......so to clean, you blow on the outside and shake out the center.

Pipes could be a factor; won't know for sure until you find a set of stockers. Stock air filter is more important than stock pipes.

If all else fails, my personal recommendation is to get the Seafoam OUT and use some "real" carb cleaner. If you haven't seen my opinion on that in a previous post, I'll be happy to repeat it. :whistle:

Your post was perfect......in that (I suspect) you didn't leave out ANY important details.
Much better than most. :roll:

Keep us posted with your progress.

[varatiki]

Originally Posted by alantf

I know you've drained the tank, but when you said that you'd run out of fuel, it set me thinking. The gz has a reserve of sorts, so you should have been able to keep going. Attached to the petcock (inside the tank) is a short pipe. In "run" fuel flows into the top of the pipe, until it drops enough to be level with the top of the pipe, when no more fuel will flow down it. Switching to "reserve" lets you use the fuel that is sitting at the bottom of the tank, below the top of the pipe. This is also where the gunge sits, waiting, so you could have got some "bigger" gunge in the carb than the carb cleaner could shift. Also, it's not unknown for the pipe to fall off, so that you're ALWAYS using the fuel from the bottom of the tank, & you have, in effect, no "reserve". BTW don't forget that the LONG side of the petcock lever points to whichever setting you want.

You may well have an electrical problem (battery?) but it also seems like you may have a fuel problem too. Best of luck. :2tup:

Just to touch on this one really quick. I ran out of fuel while in the "On" position when originally bringing it up from Oregon. I just ran her up to over 200 miles on the tank and was expecting a low-fuel light as I am accustomed to (brain fart). Once I switched it over to the reserve tank, I got it fired back up, stopped by a gas station, switched the petcock back over to the "On" position and drove the rest of the way home without incident.

When I drained the tank, I know that it was as empty as I could get it and only drops would have remained (the tank was physically detached from the bike and I rotated/shifted it until all the fuel was out and I couldn't hear any more sloshing or motion inside). I also recall that there was a screw in what I'll call the top of the engine that I removed that further drained a little fuel after tracing the fuel line from the tank into the top of the engine.

[Easy Rider]

Originally Posted by varatiki

I also recall that there was a screw in what I'll call the top of the engine that I removed that further drained a little fuel after tracing the fuel line from the tank into the top of the engine.

I wouldn't exactly call it the top of the engine but that's probably the drain screw on the carb float bowl. Sounds to me like you got a good drain.

[JWR]

I may have missed this, but spark plug???

What color was the end... brown I would think.

Jerry

[mrlmd1]

You can jump the bike with a car battery all you want, but DO NOT have the car engine running or the car's alternator output can fry all the electronics on the bike. Any 12v vehicle battery can jump the bike to start it, just leave other engine off.

[alanmcorcoran]

Varatiki,

I am whatever the opposite of a mechanical genius is, but a lot of your issues are similar to ones I experienced on my GZ. I can't say for sure, but I think they were ultimately resolved by a thorough cleaning of the carburetor. Unfortunately, there was a lot of other stuff done (with valves, the emission canister, even a prior carb cleaning) so the waters were muddied. There are lot of posts on here about the dangers of drilling holes in the pipes and messing around with the exhaust in general - most having to do with adjusting the richness of the mix, and your shortened pipes may have contributed to an improper fuel mixture - which, over time gunked up your carb. I tried a couple cans of Seafoam to clean mine, but it took a dealer actually getting in there (twice, or three times) to get to get me back to clean running. I think I effed mine up by over filling the oil, but I'm not sure about that either.

In any case, if you feel competent enough to do a thorough cleaning of the carburetor, I'd recommend that. Make sure you use the appropriate amount of choke and your idle is set properly, etc. (sounds like you have that covered.)

The carb problems lead to idling problems and starting problems, which lead to the battery drain, and it sounds like you have been right down the same path.

[trykemike]

You have received some good answers. I noted that you stated that the exhaust had been modified. On all motorcycles any change in exhaust requires a corresponding change in fuel mixture to a richer setting. There is a post in the How-To section describing carburator modification in detail. The bike runs lean from stock. I experienced the same "gasping" sensation on my bike stock but richening the mix solved that issue. Jump starting proved that the battery is currently low.