Multi-problemed bike (electrical + ???)

ImaginativeFig · 01-22-2014, 11:25 PM

I don't even know where to begin... I have a 2003 GZ250 with 8,046 miles on it that I suspect is having multiple problems. It broke down back in October when I was on my way out to the Texas Renaissance Festival, then some friends who work out there said they'd see what they could do, but they were busy and only got around to ruling out a couple of things before the Fest was over. By the time I got it back it was finals, then I went back to Oregon for winterbreak, so my bike's been sitting around worsening.

The current (haha) most pressing issue is that the battery is losing charge super fast. I had a friend come over to help me poke around at it and he brought a tender over, the tender would charge it up, then we'd stop it and watch the voltage plummet about a tenth of a volt per second. It would always slow down eventually. Before we hooked up the tender, the lights would turn on and it would try to start, but various times after that the lights were barely visible. I started following the service manual trouble shoot guide for battery running down quickly

I have no accessories
The current between the negative lead and negative terminal was 0.24 mA (which I understand to mean that the battery isn't leaking)
I couldn't measure the charging voltage since the bike won't start...
I started to try and check the stator resistance, but it got dark and I called it a night

In addition to that, I've got a fair amount of oil on the cooling fins, much like kongje did in his thread "Source of oil leak?" It looks like the respondents to that thread said to tighten the exhaust bolts (I guess these are the same "EXHAUST PIPE BOLTS" mentioned in the periodic maintenance section of the service manual?) and there was a bunch of talk about gaskets and o-rings which were variously disputed... but would a leak there cause oil loss when the bike isn't running? I could have sworn I had oil back when my bike broke down, but I don't appear to have any now (yes, I checked with the bike upright, I even leaned it to that side.) I haven't noticed any fluid spots of any sort under my bike, where could the oil have gone? :confused:

Other than that... the bike doesn't go. Even when the battery seems to have a charge (lights turn on, and start-y noises happen [my friend said it sounded like it was turning over]). Spark plug's new, carb's been cleaned, I believe my Rennie friend said something about spraying starter fluid somewhere and it not helping. His conclusion was that I needed to do a compression test, but I guess first I should get my electric system in order... right?

I'd really like my bike to be running when my next job starts in 2 weeks... do y'all figure it would be more likely to happen if I sent it to a shop or can I try to fix it on my own (/with help from more knowledgeable, better tooled friends). My fears with sending it to a shop is that they might take a long time to fix it (since they have other bikes to deal with) and/or, they might cost so much that I can't afford it (I'm tight on money until this job starts up)... my fears with attempting to do it myself is that I might mess it up and/or have to send it to the shop after all anyway.

Sorry for being super long winded. Conciseness has never been a strong point of mine.

Actual Problem and Lessons Learned
(So someone coming on this thread later doesn't have to read all of it [spoiler alert])
The actual problem keeping the bike from starting was that the cam shaft had snapped in half. This was found after running all the basic easy tests (new gas, check for spark, etc), I checked for compression with a compression kit borrowed from the mechanic down the street, found it wanting, checked to see what the valves were doing, they weren't moving at all, checked to see what was up with the cams and found the problem. Pictures of that mess on pg 14. Suspicion is that the break was either due to shearing force caused by parts not moving right because of low oil, or perhaps due to manufacturing flaw.

The battery problems described above were fixed by taking it in to be charged at the mechanic, we must have failed to charge it correctly with my friend's charger.
Lessons learned: (added as I review the thread)

Be prepared for your repair to take waaaaay longer than you expect. Patience really is a virtue
Keep up with maintenance (especially, keep an eye on your oil!)
If your battery's being weird, get it charged/tested, most places will do it for free
Yes it's fine to change oil cold if you can't turn the engine on, it just takes a bit longer and it's harder to tell if you got precisely the right amount in
If you have the OEM spark plug tool, never lose it, also, be kind and pass it on to the next owner. To get mine out, I used a 18mm long socket and an extender, but at that point my deal was so long, I had to take the gas tank off.
When loosening a bolt, make quadruply sure you are actually turning it the right way, especially if you're getting at it from a weird angle.
(Related to above) don't mess up fasteners (bolts, screws, w/e) on your bike. Just don't.
The oil drain plug is an M14-1.25 (meaning it's metric, diameter of 14mm, pitch of 1.25, the OEM part is also 12 mm long, stainless steel, with a 17mm flange head) If your bike shop doesn't have it, the auto stores will, don't let them tell you they don't. It's the same as 2009-2012 F350/450/550 Super Duty truck, among others.
If you're ever having trouble finding a special bolt like that, get one of the customer service peeps to give you the specifications (particularly diameter and pitch) and then google those and see what else uses it
Yes, the starter plunger (choke) should come fairly freely when you unscrew the nut that holds it to the carb, if it refuses, it's probably gunked up and the spring's probably being crappy. I let WD-40 sit on it and eventually worked it out (I have since learned the wonders of penetrating oil and would imagine that would do even better)
Buy penetrating oil (I got P'Blaster) and degreaser (I got DuPont for chain and sprocket). Just do it. They're great.
GZ250s' gas system is vacuum fed, there is no off switch, but on or res will keep the gas from flowing if you disconnect the hose from the carb, conversely pri will make it flow freely.
There is a drain screw on the bottom of the carb, unscrewing it will let gas out the float drain tube so that your disconnected carb doesn't randomly spit gas at you
After reconnecting your carb, prime it for a few seconds to re-fill the float...
Before you prime the carb, make sure the float drain screw is tightened, unless your floor is thirsty for gas. (Around page 10 are lots of good carb tips that I'll probably need again later)
The screws that hold your float bowl on are JIS #2 because Japan hates you. (Getting a JIS screw driver may not actually help you, however, because your carb hates you too)
If spark's good, battery's good, the bike's turning over, the carb's clean, and starter fluid sprayed in the air box doesn't make the bike go, check compression (you may be able to borrow a compression test kit from a mechanic if you're friendly and willing to leave a deposit)
GN250 cylinder head (along with most other parts) is interchangeable with GZ250
Ebay's great and all, but make sure you get and look closely at pics from all angles before you buy
When putting the generator cover tighten down the two long bolts that have the cylinder cans around their holes first, just until the cover is sitting on the bike, then tighten all the bolts evenly.
When any tightening bolts on your bike, first look in relevant sections for specific tightening instructions, if there are none, refer to the table on page 7-25 (222) of the service manual (the chart is also on page 17 of this thread)
If you have odd timing issues after putting the rotor back on, your woodruff key (the metal semi-circle that keeps the slots in the rotor and shaft aligned) has probably come out.
When pushing on the rotor by hand, turn the idle starter gear behind it to get the rotor snugged all the way back, then impact the nut on.

mainlinecoffee · 01-23-2014, 01:27 AM

The electrical could be generator stator or a short,if it's cranking but not starting it could be a safety switch in the kickstand or clutch.

alantf · 01-23-2014, 06:46 AM

First of all, test the battery. With your problems, it might be best to remove it from the bike. Charge it overnight at around 0.6 amps, remove the charger. Test voltage between terminals. Leave it for half an hour, then test voltage between terminals again. Let us know the results.

I had really bad starting problems a couple of weeks ago. I was convinced that it was a carb problem, but the test I've shown, above, showed a weak battery. Replaced the battery, and all the problems went away. But don't just guess - do the test and let us know the results.

ImaginativeFig · 01-23-2014, 09:35 AM

I do not currently own a charger/tender/whatever, I've been meaning to get one since they're pretty derned useful/important. Any recommendations on what to get? I'm low on money, but I don't wanna go cheap and get something useless.

Goose51683 · 01-23-2014, 12:20 PM

If you said you had a friend that put your bike on a tender see if you can borrow his for a day or two. It should only take a night to charge your battery and test it the next day.

In the mean time I would take another look at the engine and see if you can find any causes for your missing oil. Did you take a look at the spark plug recently? does it look fouled at all? Also, when you pull the spark plug you might as well check the compression real quick to either confirm its and issue or rule it out.

Just some thoughts.

**jonathan180iq** · 01-23-2014, 12:51 PM

Do you THINK you had oil in the bike before you let it sit or did you definitely have the proper amount of oil in the bike? That's a big difference when it comes to brainstorming, ya know what I mean?

To rule out the possibility of memory error, just change the oil. It's all of $10 and you'll know, going forward, that there is oil in the bike and that it's at the proper level. After you change the oil, clean the engine and fins and underside of the bike. This will allow you the opportunity to check for any leaks that might be there.

The bolts that people recommend torquing aren't just the exhaust bolts. Those are usually tweaked when people have an exhaust leak. The head bolts are what get snugged down when you're seeing more oil on the cooling fins. You remove the tank to access these, IIRC. Torque specs are in the service manuals.

But, to get to the real root of the problem, it's the battery. We don't have a complicated electrical system on these things. If your battery is dropping off its charge after just a few minutes, that simply means it's not keeping it. Even if you turned on your blinkers, held in the brake, and put the headlight on bright, the bike simply doesn't use that much juice.

Take the battery off the bike, drive over to Autozone or your other favorite autoparts store, and they will test the battery for free. I can almost bet money that it's bad. And even if this isn't the biggest Gremlin, it needs to be done.

The bike has been sitting for a long time, so even if every system was healthy, it's going to take some caressing in order to get it to start.

Is your gas fresh?
Have you pulled the plug just to give it a good little cleaning (replacing is only like $5)
Aired up the tires? ("Why? I want to it to crank" - just do it.)

Don't overlook the basic stuff too. You're not trying to start it with the kick stand down are you?

You can do this. You don't need to take it to a shop. We are all here for you.

ImaginativeFig · 01-23-2014, 01:51 PM

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