Struggling for speed

Hi,

I've just bought my first motorcycle (a Chituma CTM 125) and it's
struggling to get above 50 mph. I was hoping someone here could give
me a hand with where to start figuring out what's wrong with it.

Thanks in advance.

 

What leads you to believe that its top speed should be in excess of 50mph?

 

Is it brand new? Are you over 15 stone?

 

A 125 single cylinder custom bike ? Sounds about as much as you can
expect to get out of it to me.
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

A chinese copy of an ancient japanese 125 probably won't do much more than
50mph

--
Alex

"I laugh in the face of danger. Then I hide until it goes away"

www.drzoidberg.co.uk www.ebayfaq.co.uk

 

Silly bastard.

 

I think Bike reviewed this one in November last and reckoned it was good for
about 135 tops. It was making 95bhp at the wheel, 105 with the optional
Akras. IIRC, the only faults they found were the height of the bars (too
low) and the monoshock, which was too high. If it's only getting to 50, and
it's been correctly run in, I would suspect a faulty water/oil metering
nodule or possible a thrust phaser out of whack. BICBW.

--
Rich
==============================

2001 Disco II ES auto
1971 S2a 88" petrol
2006 Bandit 1200S

Take out the obvious to email me.

 

Hey, Jonny Loundeye, you come to light prace. You buy Plemium Chinee
moto-sickle, eh? You rearwy expeck it to do more than fiftee of your
miwes per hour? You havin' fuckin' gweat raff, Jonny.

Frow the fucker off Beachy Head, Jonny. It then go same speed as all
those CG125 POS that lie at bottom of criff, washed every day by
shitty North Sea, that even south coast pikeys won't wheel off beach
and sell on ebay.

**** you, Jonny Loundeye. Even my sister hate you, rong time.

 

--
Rich
==============================

2001 Disco II ES auto
1971 S2a 88" petrol
2006 Bandit 1200S

Take out the obvious to email me.

 

Is it a new bike?, if so, change the oil for something that doesn't resemble
camel tallow. Any 10/40 recommended for motorcycles will do.

Now, don't thrash it until it has done 500 miles, then change the oil again.
These bikes really do need the oil changing at 50: 500: 1000, and then
every 750 miles. They only take a litre, so it won't break the bank.

They are under geared and easily pull an extra tooth on the front sprocket.
If you are quite light, try two extra teeth on the front. Sprockets for
these are the same fitting as the blessed CG <MSOHPR> and are only a few
quid each.

They are set to run too lean, almost dangerously lean. Raise the carb needle
to its highest setting. This richens the mixture up on full throttle, flat
out running and gets it close to where it should be.

The original sparking plug is not much use, nor is the original metal plug
cap. Replace these with NGK.

Check the valve clearances. They don't come accurately set from the factory.

If you want to stay in the seat over bumps, and don't fancy sliding about on
wet roads; replace the tyres with Metzler ME22s and replace those ghastly
rear suspension units with some that have a semblance of damping.

Fit an inline fuel filter. The fuel tank has a lot of overspray inside and
the paint flakes off and clogs the float valve.

HTH

 

Its a Chinese copy of the Honda CG125. If it is brand new then the engine
will be a bit tight so it won't achieve its maximun speed for 500 miles or
so. Don't thrash it too much straight away as it needs to be "run in" for
the first 500 miles. It will also be worth checking what sprockets it has
fitted. You may find that a slightly larger front or smaller rear sprocket
will improve top speed (at the expense of acceleration). However, even at
its best dont expect more than around 60 to 65 mph.

 

Nope, CG125 copy

 

Did it go any faster when you test rode it?


--
Beav

VN 750
Zed 1000
OMF# 19

 

Oh, yes I see. Only the CTM 50 is a 'custom'.
Interesting to see that the official factory web site only claims 85
KPH. So as others have said possibly under-geared as standard.


--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

You are wrong. The thrust phaser was only introduced on the 250 version
before it was withdrawn from the market following a few deaths caused
by the fact it was 115bhp on a 250cc lump.

 

You daft bugger. VBG.

 

Raising the needle won't affect full throttle - that is determined by the
main jet. Needle affects 1/4 to 3/4 throttle

One thing that I didn't mention in my other post is that the exhaust may be
double-skinned with an undersize interior tube that restricts outflow
(possibly to meet some kind of emissions requirement in one of their
markets). Replacement with a cheap CG125 exhaust from David Silver may help
improve performance overall. They do one for the CG125 K1/B/C/E for £29.95
that should be a simple replacement requiring no modification.

 

Fewer pies.

HTH

 

*snort*

 

Chicken Chow Mein with Prawn crackers please.