Eva, the ZXR250 bitsa.

I've got a mate coming over this weekend and we're going to test the battery and the voltages coming off the leads.

I took a quick look over my battery and it seems very small in comparison to my friends EX250, I don't think it's the right battery.
I left it to charge overnight last night and I can only start the bike 3-4 times before the battery runs dead flat.

I also saw a little but of burned insulation on one of the yellow wires to my regulator. is there any way of preventing that from happening?

Also she wouldn't idle properly this morning, it was beginning to caught and sputter, just like before when she wouldn't start. I'm going to have a look at the plugs later today and see if they're all gunked up.

 

Good news. I got a new battery, and now pretty much all my problems are solved.

All that's left is to tune the carbies.

Does anyone know what the stock settings are for the carbs?

 

Well. Good and bad news everybody.

After 4 months of work, I took her in to get a roadworthy.
And she failed on 3 things.

The front fork seals are busted. The carby got all gunked over on the ride there and she kept stalling out, and they couldn't find the engine number.

about $400 for all that stuff to get fixed, and hopefully in the process they'll find the engine number.

 

Bad fuel, i think the tank had some gunk in it and the fuel that was left in there for about a week and a half.

she was ok on the ride there, but apparently the guy doing to roadworthy stalled it about 6 times. Apparently only when the clutch was in and the bike was in 1st and when coming to a stop.

 

You were right Huntsman. They cleaned the carbies, but not the fuel tank, and in the time it took me to ride her home after getting registered, she was so full of gunk that she stalled and refused to start.

I got home, cleaned out the inside of the fuel tank with rust remover and hot water, flushed it with more clean fuel but she still wouldn't go.

I had to throw on the battery charger and keep turning her over till she finally idled, but if i take her past 4krpm she stutters and begins to die, so I threw in some carby/injector cleaner into the fuel to see if that would help and it did a little.

I'm going to open up the carbies tomorrow and give them a good clean again.

What do you guys suggest to clean the tank/carbies?

 

Well, I ripped apart the carby today and cleaned it all out with some aerosol carby cleaner, took out the jets and gave them a good clean as well.

But when I reassembled her and put her all back together again, she still stuttered at the 4-8k mark.

She only stutters under load, and it's only occasionally. Sometimes i can cycle through the gears and have her sitting at 2krpm @ 60kmh, other times she just stutters all the way up to 60.

Sometimes when i'm cruising at 60 (without moving my write) the will begin to slow down, and then get a massive surge of power and she just does that over and over.

I tried bench tuning the carbs too, but i can't get my first carb to the same place as yours in your tutorial. the first carbs butterfly valve is completely covering the top pin hole.

Currently the carbs are sitting in a bucket of vinegar, I'll check them out tomorrow and hopefully everything should be cleaned out.



That's what the jets used to look like. The one on the left is a clean one, 3 of them came out of the cars looking like that, the one on the right is all brown, but not gunked up which was surprising. Even after cleaning them, she still wouldn't run properly.

 

The tank is more or less clean, it's a lot cleaner than it was, that's for sure (I forgot to take pictures)

I just reassembled the carbies as the jets and carbies were all clean (apparently they were clean to begin with) The issue could be the because the bike is running extremely rich, so rich that all the unburned fuel caught fire inside the exhaust.

You wouldn't happen to have a guide for tuning a carb? I have no idea what I'm doing. I've got a service manual open, but the image quality is so bad I can't make out what piece is what.

 

The fuel tap is set to reserve at the moment. I've got the pilot screws turned 2.5 turns out.



Just making sure that's one of the pilot screws.

The jets from left to right are 125, 128, 128, 125. Thanks for making me check, i discovered that originally they were put in as 125, 125, 128, 128 and every time I've disassembled and reassembled the carbs I've always put them back where I found them. They're back in now with the larger 2 between the smaller 2.



That link you send GI says 'Download not Avalable".

 

When I bought the bike, the owner said that he's blown the original motor, and had a replacement motor thrown in, he said it was from a 1990 model. So I assumed it's an A model engine in a C model body, but I haven't been able to find out for sure, as far as I know the A model engine doesn't fit a C model frame.

That and there are a few weld marks across the engine where things seem to have been cut and welded to fit. also the engine number has been ground off and replaced with a different engine number (probably from the original engine)

As for the o-rings, there were none on the jets originally since i've owned the bike. I think I might have to invest in a kit.

Now that I look around the carby more, there seam to be no seals at all. None on top of the carby to the air box, none on the bowl, the only seals this carby has are the dust covers for the choke plunger.

As for the blue stuff, as far as I know that's gasket glue, previous owner had put that on because he couldn't find the right seals.

I'm about to order some of those seals now.