Monday, 8 June 2020

Z250SL radiator replacement

After replacing the forks I found the radiator was leaking. The radiator had looked suspiciously wet for a while bu I put it down to the constant damp conditions we get here in the UK for most of the year, and never really looked into it because it's easier to just park the thing up at work or home and go inside. After sitting still for a few weeks after the fork testing episode it was clear the radiator was leaking quite badly, so once again I searched ebay (what did people do before it??) and found a nice looking example from a bike with 10K miles on it for only £29.50. Once again I was in business! Obviously the price for a replacement from Kawasaki was ridiculous.

Since these rads are of particularly low quality (just like the wiring, the stator, the suspension, the brake calipers..) I'll make this more of a guide so that others will know what to do when their own rad breaks up. I don't think mine's especially prone to failure, I'm just ahead of the curve..

First, remove the silly useless belly pan. It's amazing the amount of jobs that require this thing to be taken off!
Next remove the cover to the right shoulder pad, we need access to the radiator cap so that the system will be able to drain properly.

Next it to drain the coolant, or what's left of it. The drain bolt is underneath the pump:
You will probably find that you need to undo the bolts for the bracket of the belly pan so that you can move that bracket out of the way and actually get a socket on the drain bolt. Just another little thing in the way..
This is what came out of mine after 3.5 years and 21865 miles, assuming the first owner never changed it. I can only describe it as tea?
It also smelled foul. Whatever antifreeze Kawasaki are using, it doesn't work very well.

Next up is unbolt the coolant expansion tank, that's the big white thing. You'll have to do this to be able to remove the radiator cap so that you can get a socket on the bolt holding the radiator in place on the right side..
Next remove the cover from the left shoulder pad so that you can pull the hose off (difficult..) and access the bolt holding the radiator on this side.
Undo the bolt holding the bottom of the radiator in place, this will allow the rad to swing on the top mounts and give you a little more room to get to the electrical connectors behind it.
Speaking of which, you'll need to disconnect the connectors for the temperature sensor (I think? The one on the rad) and for the fan which is nestled way in there. Best of luck!
With all that done, it's now a fairly simple case of removing whichever hoses you need to remove (depending on the replacement rad you've bought and how the breaker has sent it to you!) which is done by removing the two top bolts, one either side.
You may find it helpful to slacken the bolts that hold the reg/rec in place so that you can get a socket directly on the left side bolt.


With those two removed, the radiator should basically fall off. If it doesn't then you've probably left a hose on somewhere! Old one on the left, newish one on the right..
One of the top mounts was slightly bent/twisted on the newish radiator so I set about bending it.. I think I could have done it with my fingers. These things are made of cheese! Anyway, installation is almost the reverse of removal, just bolt it back on and fit all the hoses so your new coolant won't fall out all over the floor. Then mix yourself up some lovely blue stuff (or orange if you're fancy) and console yourself that at least it's not tea.
You will need 1.2 litres of coolant, simply fill the radiator right up to the neck (keep squeezing the hoses and leaning the bike side to side to get the bubbles out) and chuck the rest in the expansion tank when you can't fit any more. You'll have to put the radiator cap on before fitting the expansion tank in place otherwise the tank is in the way. Remember to bolt the tank into place so your precious new coolant doesn't spill everywhere!

This concludes radiator replacement for the Z250SL. If your rad starts leaking then let me know about it in the comments so that others will know what to look forward to!

Z250SL fork strength testing and replacement

And so, back in February 2020, after 11.5 years and something like 135,000 miles of riding, I had my first RTA involving a member of the public. Behold!
Who's fault was it? I shouldn't have been filtering down the middle (well, I do so at my own risk) but the van does a sudden U-turn without checking his mirrors. The driver is apologetic but quickly becomes more distant after we decide not to go through insurance because I can get some forks quite cheaply, Mr Paul Wilson of Sapcote you are a nasty and selfish piece of work. Anyway, the aftermath:
Mr Wilson suggests he used to be into bikes innit and his mate can get me some cheap like. This never happens (surprise), nor is any money forthcoming to cover the cost of replacing the forks myself despite it being agreed as I helped him keep his job and keep his insurance payments lower by not going through insurance (more surprise). Luckily there were a good pair of forks on ebay available for £75, so here we go. This was a fairly straight forward swap so no in-depth instructions this time..

We begin!
The state of these forks at 3.5 years old and 21865 miles is beyond belief. Things started off badly when the mudguard wouldn't come off, I hate these stupid allen button head bolts. Also notice the drip from the radiator, that'll be my next blog post..!
I'll sort that out later..
A bit wibbly wobbly without a rear paddock stand, I should get one. Or, y'know, stick to the promise I made to myself to never buy a bike that doesn't have a centre stand ever again.

These rubbers that hold the headlight clamps/ears in place are a bear to slide up off the stanchion. I found it best to lever the rubber away from the chrome and squirt some light oil/maintenance spray down there, this helped them slide much more easily. Still very difficult and time consuming though.
Forks out..
Kinked where it bent at the lower yoke. These couldn't be straightened even if you wanted to. Disturbing given the slow speed of the incident..
Aha, fresh meat!
Aaaand in.
Now, what about that stupid bolt? Hmm can't really attack it from the inside, the rest of the mudguard is in the way..

So I'll attack it from the outside!
I stopped at this point because the pressure I was applying was starting to crack the mudguard. Now, maybe one of those easy out left hand thread thingers will work..
Of course it didn't, they never do. So I stuck the leg in the vice and drilled it proper. I was quite pleased with how this went, since I did it by hand!
There was even enough thread left in the bracket for another bolt to fit and tighten up. Job done!

Run her up and go for a little test to see if the forks are boinging like they should, oh no what now..
It was virtually trickling out. Back to ebay..!

Sunday, 17 May 2020

Z250SL stator trouble

On the morning of the 15th of January 2020 the faithful(ish) Kawasaki struggled to start, turning over rather slowly. But it had been a cold night and I figured it might just be one of those things.

Later that day when I came out from work the starter solenoid merely buzzed, which led to the great disgrace of having the second-in-command push me up and down the cap park trying to get the thing started. It didn't want to know until I'd borrowed a screwdriver off him (further disgrace) and removed the connector block from the headlight as there is no switch to turn the light off. After this it fired up no problem and, after refitting the headlight (my eyes!!) I managed to ride home. The light was dim, the dash flickered and eventually died, but I did make it home - I had less than 9v in the battery by the time I got to safety.

I decided this was likely due to the battery being well over 3 years old and being a cheaper Thai Yuasa, I'd once had a battery fail similarly on the CB250 - that one could barely power the neutral light after a warm day sat outside. So..
Those reading this from the UK may know that it is illegal to sell batteries with the acid still separate as certain scummy elements of society can't be trusted to not squirt it in people's faces. This was sold as "acid-added" but it wasn't. I'm okay with this, I just found it amusing. It's not like the police are going to check what's being sent through the post! Anyway, running voltage with the light in:
I have a sneaking suspicion that 12.4v isn't quite right. Also the light looked decidedly yellow:
If it jumps considerably when I disconnect the headlight that may mean I have a charging problem..
14.2v. Bollocks.

I refitted the headlight and decided to give it a run to work anyway, perhaps it'll charge happily at higher revs? It did not, running along read 12.7v and by the time I got home I had around 10v, no doubt helped by the new and freshly charged battery. Time to check the resistance and AC voltage of each of the stator coils.. Which means time to take the tank off yet again. I'm becoming quite good at it now!
The connector is a big one at the front left with 3 yellow wires running into it. When running some coils produced 39VAC while others managed 25VAC, and one set of coils (i.e. one wire in the connector) read 10 ohms of resistance while the other two read 2.8 and 3.2 ohms. Yep I've got my first stator problem to deal with, superb.

So, here's a guide of how to replace the stator on your 250SL. I have a funny feeling this might be a popular post in the future! Start by removing the stupid belly pan that does nothing but get in the way, then remove the front sprocket cover and the cover of the reducing gear for the starter motor. This is all straight forward, just bolts. Also remove the neutral wire because it'll just be in the way if you don't.
You will also need to drop the oil as the alternator on the 250SL runs in oil, so when you take the cover off all that oil will fall out. This is made particularly fun because the bike does not have a centre stand so it will keep dripping for as long as you leave the cover off.

Now, how to get the cover off! Remove all the bolts that hold it on (including the two that were behind the starter motor reducer gear!), unclip the 3 wire connector and unthread it from the rest of the wires that work their way up the frame aaaand it should pull off. I tried this to no avail. I tried rubber malleting it to no avail. I tried levering it off against the starter motor to no avail. In the end I used some washing line and brute force..
A good couple of tugs had it free. There is a seal around the starter motor shaft that is very tight, KLX250 owners have the same problem.
Hmmm. Doesn't look too good.
This bit seems alright though, thank goodness. What a pain that would be to get off the crank!
So, simply remove the two JIS screws that clamp the wires in place and then remove the three caphead screws that bolt the stator in place.
There was no threadlock on the bolts, they were just tight. Do use the correct bit for the screws, if the driver cams out and you mess them up you could have a real job on your hands. With the stator free you can closely inspect for damage (as if you'd need to!).
Well there's your problem. At least I was right! I managed to get hold of a replacement stator from an ebay breaker who had broken a 1500 mile bike, mine for £78.95. I noticed there were also some Chinese units for sale for around £50 but I cannot comment on them, though the pictures looked exactly the same as the Kawasaki ones. Bolt the stator in place and clamp the wires without pinching them (which seems to be all they want to do..). Don't bother with torque specs, the fasteners aren't new and the threads aren't clean.. Just do them up so they won't come loose.
Right, time to put it all back together. Simply replace the alternator cover complete with new stator and bolt it up. I actually bought a new gasket for this but the original didn't tear when I pulled the cover off so I just put it all back. The gasket part number is 110610891 if you're paranoid. Also watch for the way the flywheel will pull the cover into place and the way that the wires love to get trapped between the cover and the crankcase - don't chop them up by tightening all the bolts down! I nearly did..

With the cover bolted into place the only other difficult part is refitting the starter motor reducing gear. This is difficult because you need to get the teeth to line up, for reference the gear needs to go on this far:
Just keep trying until it fits. After that simply bolt everything back on (no I didn't use any sealant or gasket on the reducer gear cover, no it doesn't leak), reconnect your electrical connectors and put the tank and all the plastics back on (if you're confident). Refill the engine with oil and it's time to give the starter a prod..
Job's a good 'un. What'll be next I wonder..?