petrol make a diffrence ?

[flearider]

on the smaller bikes would the grade of petrol make a difference ?
to speed ?

[arry]

If you're talking octane rating - extremely unlikely.

[Rogerborg]

Higher octane might decrease your top speed a little on a 4T 125.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[rpsmith79]

Would need to be a high compression engine to even make use of the higher octane rating (reduces knock at high compression) and would either need to be tuned to use said higher rating fuel if old school carb'd, or could possibly retune itself if injection, as long as it has some sort of knock sensor and the ability to change the fueling/timing based on the output of said knock sensor
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Current Bike: Honda CG125 ES4 // Honda CB600FS Hornet // Triumph Street Triple R

[flearider]

I'm finding the gsx s 125 a lot slower than my old cb125f
I was told it could do 80 .. and taking it easy it just seems to hit 60
now the cb125f could sit at 65-70 all day ..
just seems strange a £3200 bike can't match it
and yes I know it's still wearing in but with 300 miles on it I'd of thought it was most of the way there ?

[The Shaggy D.A.]

[c_dug]

Hitting 80 on any 4t 125 won't be done by taking it easy - try not taking it easy and see if it'll show you 80 on the speedo that way.
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[Baffler186]

I'd go out on a limb and suggest that keeping your chain clean and well lubed will get you more to end mph than using premium fuel. And we're only talking 2 or 3 mph as well. These are tiny figures. If there was a cheap, easy and legal way of getting more speed out of 4t 125s (L legal) then everyone would have done it by now.
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Current: 2009 SV650 S, 1990 Kawasaki GT550
Previous: 2009 CBF125, 1998 GSF600, 2004 FZ6 Fazer, 1978 CB400a Hondamatic

[flearider]

[Suntan Sid]

[BusterGonads]

[Fizzoid]

The kids on the 125 FB groups all claim their bikes go faster on SUL, so it must be true!
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Rogerborg wrote: It'd certainly make it easier to ego-find my own posts on pages, given the number of fags (gay like traps) who insist on putting my name in their .sig

[Teflon-Mike]

ISTR that the running in advice on my brand new 125, nearly 30 years ago was, to keep it under 40mph for the first 100 miles, then up the revs 1000rpm for every extra 100miles, or something like that.
Basically I don't think it got to 60 until it's first service!!!

80mph? On a 4T-125? Err... yers... 'indicated'... perhaps.

Thunk for you... the 1977 CB125Twin, at 17bhp.. two and a half braying donkeys more than max permitted for A1-Licence regs, was probably THE most powerful four-stroke 'production' 125 ever made.. it could just about nudge 80, through two-way times traps; the 'aerodynamics' offered by the fancy party frock on a GSXR-125, might help a tad... but are probably off-set some by the drag of the fat tyres!

Either way, 80mph is pretty optimistic for a four-stroke-single-125....ESPECIALLY one that hasn't merely NOT been run in yet, but hasn't even clocked half the run in mileage!

And you are ragging the crap out of it, trying to find out whether the mag-propaganda holds up?

Before its first first frigging oil-change

And you are wondering if Super-Unleaded would make a difference to regular?

The mind just boggles.

And that's before it strays to ponder, this is at least the chaps 2nd 125.. and about the most expensive one on the market... WHY!?!

If 'fast', or even 'cool' is the imperative here; why no tests, licence and a bigger bike?!? I mean, if under 19 and stuck on A1 'cos of modern licence regs... how long until A2 could be done, and something like an SV650 could be bought, PROBABLY for, oooh.... less than the new-bike depreciation rolling GSXR-125 out the blinkin show-room! And NO bike looks 'cool' with an L-Plate to belie the fact its just NOT a 600 or anything but what it is; a little commuter bike in a party frock! If over 19 and A2 and a big bike a possibility? WHY even go there at all!!!

But hey... not my money... actually probably not OP's either.... likely banks, finance companies or Daddies... so who cares.... well... until the bill to replace the fancy fairings or rebuild the motor comes in... carry on.. its a learner-bike... one way of t'other, you gonna learn... maybe.. we can hope!!
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[Rogerborg]

Nothing about improving the rider? No revving out in every gear?

The perils of daytime drinking and falling asleep at the keyboard.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[flearider]

ok that's me up to date .. thx you all for your input
yes I think it will take 6 months for me to get full licence (well the money to)
so will be taking care of what I have
thx again

[Teflon-Mike]

[WD Forte]

https://i.imgur.com/rXdJ78p.jpg
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bikers smell of wee

[c_dug]

[stevo as b4]

Filling it with SUL and wondering if it will go faster smacks of desperation IMO and possibly a regretted purchase. Im no GSX 125 fanboi, but I'd also be running it in more carefully and with a couple of oil changes under its belt before trying for a top speed run.

Are you serious about wanting to tune this bike or are you desperately looking for something that isn't there, or trying to deny a poorly considered bike choice? If you are serious about tuning it then how much are you prepared to spend £1000, 2000? more?

I've got a 125 among my bikes that Im wasting money on tuning, and I don't even want it to go any faster. Im doing it for bloody mindedness and I've spent over £1000 just on parts so far, and I've still got the work and fitting to do, plus set up and dyno time. Im also fully prepared for regular engine re-builds, are you?

[Courier265]

[dydey90]

Look at the manual, it should tell you that you’re due a service after 600 miles / 1000km. It’s basically just a check over, but it will most likely be running on mineral oil from new, which is apparently not as good as synthetic due to natural inconsistencies.

https://rideapart.com/articles/how-to-break-in-a-new-motorcycle-engine

Have a read of that and report back in 1000 miles time. If the actual top speed is 66mph, it could well show 75-80 on the clock once it’s run in.

Unfortunately, 15bhp is all you can have right now so if you feel like it’s not enough, just treat it as a training period until you can get through your test. If money is the main obstacle for you though, perhaps buying brand new wasn’t the best idea. If you are having second thoughts, you should be able to return it within 30 days, although as it was new and has therefore lost significant value I don’t know how this would go.
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This post is probably not serious and shouldn't be taken literally.
Past: CBR125,ER6f NINJA 650, ZZR600 Current: VFR750

[Ste]

Try running your bike on super unleaded expensive petrol and see how much faster it goes.

[Old Git Racing]

It doesnt make it go faster, but it will stop all the ethanol crap bunging your carbs/ FI system up. I always put super unleaded in mine because I can and its better for the engine.

OGR
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2022 Tiger Sport 660 2019 Street Twin 2003 K3 gixxer 1000 1998 Srad 600 track hack

[Rogerborg]

+1 to bike speedos being for novelty purposes only.

[TheGazWaz]

I've seen the GSXR125 in the flesh and I have to say, I like it. I'm a bit bias but if I were 16,17, 18 or even 19 and someone said to me give us £60 a month and you can have this bike I would probably have done the same because shiny ruled my head when I was that young along with a few other things that can't be talked about on this family forum.

Only 6 months down the line do you realise I'd actually be paying it for the next 5 years when I'm in my 20's and would most probably not want to be on a 125.

When I was 18 I took a £2500 loan out. Bought an RD125LC (yup.. that long ago) it wasn't new by any means but it was a hell of a bike.

A week after I got the loan I was made redundant. Took me 7 years to pay that loan back. The bike was scrapped 8 months after I had it. Regrets. yup... Something to tell the grand kids though.
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Went like this.. 43 years old(2013) decided to do CBT to get a 125 for new job. Bought 2011 YBR, loved it for three months then hated it because it was too god damn slow. Did DAS 4 months later then bought RF600 Loved it, sold it bought Bandit 1200(K3). EFFIN lOVED IT. Wanted something a bit more sporty so got Triumph Sprint ST 955i (53). Not sporty enough so now on my GSXR 1000 K3 and absolutely love it. 1 year down the line, nearly died way too many times on this bike. Sold it. Had a 6 month break. Missed biking so now, Aug 2019 have a 1999 ZX9r. What a beauty she is too.