@jonne123

No disrespect meant from the start! But I’m guessing that you’re about 17 and haven’t ridden a great deal of bikes?
Every 125 Has been restricted to about 12bhp since the late 80’s AFAIK. Any bike that is significantly above that has been de-restricted and/or tuned.
You can unrestricted early dtr’s by ‘pinning’ the power valve open. This will give you higher bhp but will basically make the throttle an on/off button with terrible response.
Later bikes I don’t know as much. You can unrestrict them and the variable power valve will still give you better low rev torque/response (I’m guessing that is what you mean by throttle response?)

Do some reading up on deristricting your year model bike, then do some riding. Stop worrying about numbers bud, enjoy a wicked little bike for what it is, before yearning for more...

Kudos on doing your own thing bud. Too many people throw excruciating amounts of money trying to put a shine on an already overpollished turd! 🤪

Congrats bud! I thought it be painless in the end...

It WILL fire up with a new CDI, unfortunately online buying is a fukin shark feeding frenzy of a$$hol£s all caring about one thing. The amount of times I’ve been shafted on fleabay is unreal. Brought a headlight that came without the bulb holder or rubber, the bloke had the neck to tell me that I was confusing his with another listing, conveniently after his pics were down. The only reason I nodded was cause it was complete...
Another bloke changed the listing twice while I was between messaging. Once to up the price £40 then to change from 3 wire to 5wire servo! Same listing number an all...

4 strokes always have air movement in the case/block, the pistons pumping up and down displace air. You can get over pressure from worn rings/ piston blow-by...
You ain’t going mad, sanity is just a learning curve 🤪

Trouble is it could be any one of these switches:
Key Ignition
Handlebar kill
Sidestand
Clutch
Neutral

Or these parts:
Pulse generator/pickup
Fuses

Or just a break in a wire.

I’d start off by checking fuses, then doing continuity checks on the switches, then the wires
Check for volts at the coloured coil wires, volts at pick up while cranking the starter

If it’s connected to the ignition it could be the cause of your problem, specially if you’re neutral lights not working...

Wasted spark is when they both spark at top dead centre?
Have you not gotten any old coil off of another bike? Even a single one that you can get to spark? It would at least prove the rest of the circuit was on par...

Congrats! It’s nice to see someone doing their own thing! Nearly every ride I’ve ever had has been a butchers tripe mix of a thing. Mostly through necessity though!
I’d really love to do a street tracker out of an old Honda CB 200 twin. Nice & lite yet revvy & torquey enough. Think of Girl with the dragon tattoos bike with attitude ️
They aren’t easy to find anymore though...

There’s always Sod’s law as well. As soon as I get interested the price goes well past my shoe~string budget!! 🤪

I’d get a pump up spray bottle and squirt it down on a hot dry day. Start on the obvious ignition bits. Plug, coil, CDI. Try the sidestand switch as well maybe. My mate had probs with the sidestand/ignition relay as well. It would only start with the ignition switch off...

The high rev thing is weird though. Have you looked at the plug straight after it dies? See if it’s wet? Specially if you been playing with the jets...

Cheers bud, that’s something to work with. I’ve got a good 3bn, my reworked 3mb and another 3mb (that I forgot about till now) that is battle~scarred but otherwise original.

@declan
Sorry, didn’t mean to offend. Plus I gave up a looooong time ago!

In all seriousness, I’d like to know what the cc of a 3MB head is? Mine had to be reprofiled to get rid of piston ring explosion marks and I’m not sure if it was skimmed to the point that it kept the same compression ratio

@declan
Wow, I wish I lived in the same reality as you...
I think

I didn’t know bikes had any offset? I thought it was a car thing. I’ve seen it on bicycle back wheels where the spokes are more ‘straight down’ on the cog side.

Soooo, it’s an expander ring, for bores that have a bit too much clearance. Goes behind the thinner ring, on the bottom of the piston. Not recommended to be fitted if you have a nice tight fresh bore...
Got an email from PJME

Yeah. Mitaka. I called it something entirely different in the thread title and edited it to Makita. How embarrassing?!!

The barrel and piston have just come back from PJME so I trust the tolerance, ect. The barrel is a 3MB and it says TZR on the piston box. I’ve never had one like this before but I have seen them online in pics, ect.
The piston that was in before was a wossner. Both the rings looked identical, so I don’t really know what to make of it all. Just want to get it right, what with being the sixteenth ‘registered’ owner. I feel I have a duty of care for the old plodder

Hi! Just got my barrel and Bits’s back from pjme’s and have a question about Makita pistons. where does the ‘crinkly’ backing ring thing go? Top or bottom ring? I know that the top is a keystone ring and the bottom is plain, but i don’t know which one has the backing ring thing...

Yeah, they is diddly

Old Hondo VFR400, if you can find one these days. My tuppnies worth ️