WD-40

Anytime I have to wear a suit I wear the trousers and shirt and put the gear on over that and then fold the suit jacket and put it in the top box. I think it's a 50L Givi box. It's not ideal but it does the job

If a young lad really wanted to do modify his 125 with a big bore kit or some other major mod he'd do it no matter what anyone said. I don't think a few people on a forum giving sensible advice could put him off the idea if he was really serious about doing it

The over tightened chain would only really be a problem if you rode it with it very tight. If you didn't ride it it shouldn't be a problem and it would have nothing to do with a fuel problem. The main thing is check the oil level, see if it's high. You could check any leaks or the puddle that was left on the ground by feeling it with your fingers. If it's oil it'll feel slippery and stay on your fingers, if it's petrol it'll evaporate.

Snapping the chain adjuster bolt wouldn't have anything to do it a fuel problem. Is the oil level high? Does the oil stink of petrol? You could take the spark plugs out and see if one is soaked in petrol. Petrol in the oil on a carb bike is usually from a float valve being stuck open in the carb.

If you haven't done it as dynax said you could take the spark plug out and check if it's got spark. If it doesn't have spark you could swap the spark plug on the bad cylinder with a spark plug from a known good cylinder and see if the problem moves to the good cylinder. If the problem is still on the same cylinder as before swap the coil on the bad cylinder with the known good cylinder and see if it moves. If it's still not firing on the same cylinder I'd do a compression test and compare the compression on the bad cylinder to the other known good cylinders. If the compression is good I'd give the carb a clean.

There's the procedure from the owners manual. https://2rom-prd-data.hondamotopub.com/om/HMEE/CB125F/2017-2018-2019/CB125F_32KPNB11_0.pdf Checking the Engine Oil 1.If the engine is cold, idle the engine for 3 to 5 minutes.2.Turn the ignition switch to the (Off) position and wait for 2 to 3 minutes.3.Place your motorcycle on its centre stand on a firm, level surface.4.Remove the oil fill cap/dipstick and wipe it clean.5.Insert the oil fill cap/dipstick until it seats,but don't screw it in.6.Check that the oil level is between the upper level and lower level marks in the oil fill cap/dipstick.7.Securely install the oil fill cap/dipstick

A float valve not seating properly or float height problem would explain your previous question about being too rich causing black spark plugs https://www.themotorbikeforum.co.uk/viewtopic.php?f=5&t=72700

If I was you I'd contact the dealer you bought it from and report to them and follow their instructions, then if something goes wrong with it in the future they can't say it went wrong because of something you did

If you only want to change the can you could measure the diameter of the exhaust and get a universal fitting can with the same diameter and make it fit. You can get fake Akrapovic cans really cheap. One of them might do the job. If you want to change the full exhaust it's a different story. You would have to find one made for your bike.

Was it ok and then all of a sudden it started rubbing or has it always been rubbing?

I tell you what, if you ever write a book let me know because I'll buy it

Ahh I follow you now

I beg to differ I actually tested this with some bearings I got for my wheel balancer It came with some cheap ones and I ordered quality ones and the difference was night and day and this was with dry bearings So you're saying the quality bearings that you put in were better than the cheap ones that came with it? So we're agreeing then aren't we? Buy good quality brand name bearings not cheap Chinese ones. I thought the point of that video was to prove that the cheap Chinese bearing was better than the more expensive German one? And he was proving that by showing that the German one spun longer so it was worse quality than the Chinese one or did I not understand it right? I'm saying if you wash the grease out of a bearing it'll spin longer like in the video so the video doesn't prove anything

Yeah no probs. Took a year tbh and I was still learning when I sold it (though I did get comfortable riding very fast indeed) but no problems with it or my abilities touch wood 14k miles later. Maxed it out, ground down my pegs (on closed roads of course). Fair play. Not easy to go from a 125 to 1000 and be able to ride it properly. I still think it makes more sense to go up the CC gradually rather than go up in one huge jump. When you're learning to do anything you don't generally go from beginner to expert in one jump you have to build your ability over time but I guess some people can do it.

Best of luck with her

That video doesn't really prove anything. All he's done is wash out the oil in the one that keeps spinning or he added oil to the one that slows. All roller bearings will spin like that if you remove the lube and put no load on them. He could even be comparing two identical bearings from the same packet just one has lube and the other doesn't. You could prove it to yourself if you've got one of those fidget spinners. Spin it dry and it goes forever. Add some oil or grease and it slows down a lot quicker because the lube is causing more drag. A free spinning no load test like that is not really valid because bearings are designed to have a load on them so you have to test them under load. Best to stick to the quality name brands and buy from a proper source.

The ones I've used are SKF, FAG, Koyo, NTN. All you need know to get the correct replacement bearing is the code that's printed on the side. Go into a proper bearing shop with the code and they will give you the correct bearing but if you're interested in knowing more, all the main manufacturers produce bearing catalogues to help engineers select the right bearings for their application. There's great information in them. https://www.skf.com/binary/77-121486/SKF-rolling-bearings-catalogue.pdf http://www.nsk.com/common/data/ctrgPdf/e1103a.pdf

Can I ask are you any good at riding it? And how long did it take for you to get comfortable on it?

A relay can switch on the 0V earth side or the 12V it doesn't make a difference. It's just a switch causing a break in the circuit so current stops flowing. It doesn't matter if the break is on the 0V side or 12V side If you look at that diagram above at the starter motor. The triangle symbol below the starter motor represents earth or ground or 0V. The black wire is the 12V wire so in that circuit the relay is switching on the 12V side

Better off starting on the 650. A novice on an R1 is asking for trouble.

Falling over on a u turn is a rite of passage for every biker Nothing to worry about. Especially if it's not your bike

There's some information on them. Don't know if it's correct. https://2fiftycc.com/index.php?threads/shindengen-regulator-rectifiers.10005/ I think there's a lot of fake shindengen reg/rec sold on the internet so be careful who you buy from

What's your general location? That would help

I use a basic one like that with an extension on it to get past the exhaust headers. Works fine. You have to make sure you buy the correct diameter for your filter

There's a parts list. I wonder could we figure out the connections from that https://www.3xmotorcycles-superstore.com/home/SAPZZ125/ZZ-125-Parts There's some pictures of his loom https://www.ebay.co.uk/itm/SFM-ZX125-zx125-Wiring-Loom/174300460531?hash=item28951df5f3:g:SBoAAOSwzxBe0ki1