WD-40

I like your ambition but you're living in fantasy land. No one is going to do that work on a 4 stroke 125 road bike unless they're completely bonkers

Here's one for pz carbs. Might be of some help. http://www.ccwthariders.com/uploads/9/7/7/9/9779070/pz_carb_tuning_manual.pdf You would probably need the workshop manual for your model bike to get the exact setting

Sounds like a good plan to me. Check for tight links in the chain too. If you've got tight link you should replace the chain. And check for wear or damage on the front sprocket. The front sprocket wears faster than the rear

There's a manual for a 90 - 97 ZZR600. The chain adjustment and wear info is on page 10-4 and 10-5 https://www.dropbox.com/s/bu43di24gaiwcgi/Kawasaki%20ZX6%20ZZR600%2090-97.pdf

I googled those numbers and I can confirm that is definitely an oil seal

If you've got a car you might as well play it safe and take the car

It looks dodgy doesn't it? It's up to you if you think it's safe or not. I think the axle and the axle nut are taking all the force so you should be ok but I would order that bolt now and replace it asap.

If you can get the chain slack in spec and the wheel straight you should be ok to ride it. But you have to be careful not to over tighten the chain. You can do a lot of damage if it's too tight. You could ruin the bearings in gearbox or snap the chain which could cause a crash. You tightened that adjuster a long way. Usually they only need a turn or two on both sides to get the correct slack. Your chain could be way too tight now. If it is don't ride the bike. I would order the broken bolt. It makes no sense to weld the old one if it's so easy to replace it

There's a nice picture of the adjuster. You would take the two bolts out and take the plate off and the threaded bolt that is snapped should come out, put your new one in and put it back together

I'm not sure if this is your exact model of bike, check it out yourself but I had a look at the parts manual in the link and it seems that on a ZZR600 you can replace just the bolt that you snapped by itself which is handy. Take the axle out, take the adjuster out, take the broken bolt out, put it back together. Should be easy. https://www.oemmotorparts.com/oem5.asp?M=Kawasaki&T=ZZR%20600&Y=2004&L=KA-ZZR600-8&O=Swing%20arm&F=KA-ZZR600-8_BF&L2=KA-ZZR600-8_BF You could still ride it the way it is if you really have too but you won't be able to take the slack out of the chain. It could be too slack to ride safely. If it's very slack you would risk it jumping off the sprocket. It's up to you if you think it's safe or not.

What bike is it? If you can find a workshop manual, it will tell you what the standard settings are for the carb and you can check what your one is set to. Someone could have adjusted the idle mixture screw or raised the jet needle or increased the jet size

I've not got much trust in chain since I saw this video a few years ago.

It could well be fake. The CE looks quite close together in your picture. According to that article the genuine CE marking should be spaced apart with the E starting in the mirror image of the C

https://support.ce-check.eu/hc/en-us/articles/360008642600-How-To-Distinguish-A-Real-CE-Mark-From-A-Fake-Chinese-Export-Mark

You are getting 9 quality screwdrivers for that price. No more chewed up screws and they should last a lifetime for an average diy home mechanic. It's a one off investment that what you have to tell yourself

Nice work That's the cleanest wheel I've seen.

I've heard these Vessel JIS screwdrivers are very good quality and reasonably priced. They're also impact drivers which is a bonus https://ruggedroads.co.uk/JIS-Screwdriver-Vessel-Megadora-IMPACTA-P3-x-150

Are you getting a "big girls bike" @gymwitch lol. For a very little money a JIS screwdriver can be bought from Amazon or the bay and I would strongly recommend you get one as using phillips or pozidrive will cost you fastenings and cause growling lol. Cheers Ian Here's a top tip. If you've got the factory tool kit that comes with the bike there's a JIS screwdriver in there

I think you need to bring it to a proper mechanic and get them to checked it out in person. They will tell you what the damage is and if it's safe to be put back on the road or not. Don't take a risk with it.

I have a pipe off a trampoline that's come in handy a few times for a bit of extra leverage

It's as raesewell said it depends on the beam pattern that they're putting out but if you look at the sales brochure they are definitely marketing them as fog lamps https://www.kawasaki.co.uk/en/accessories/lighting/Versys_650/2020?UidCat=01FFWUYNBkU9Iw&UidSubCat=0546WlhZXFhaWllYWFlYWVhcW1pZRg0GRT0j&CodeBaseInternal=0177IyQtXl1Y&Uid_Model=0894XFBaUQpYXlkMWloOXFFbDQkMCV5fDlhdCl4OUFwJXlo&Uid=0957XgkLXg1RXFwOX15YXAlbC1EMCl1eCl5aWgkMCw4LXw0

ah now I follow. I thought you were trying to convert the standard fog lights that come on the bike into running lights. Didn't realise you were talking about aftermarket bolt on lights.

haha

It's an interesting idea. I wouldn't do it because you'll have to spend the money to buy what you need and you'll have to cut into the bikes wiring and at the end of it they'll still be fog lights. Just dim ones

I'd check the oil level is good, drain the tank, new fuel in and a new battery and fingers crossed it fires up. Then do a big smokey burnout for your brother