GN250 speed

[T J Crunch]

Hi,

thanks for any advice, I have recently started riding a Suzy GN 250, the top speed I can get is maybe 90 Kph...

is this right.... I thought maybe it would do 110 ish... the bike is an 83 model, has done just over 30k, and has been parked in my shed for the last 18 months...

have given it an oil change, removed and cleaned the tank as best as practically possible, and added a little injector cleaner to the fuel,

Cheers, Tim.

[Captain_Salty]

Are you sure your in top gear? Should do a little over 100.

[Drew]

I imagine the carb will need a proper clean. A new plug, and check the valve clearances.

[T J Crunch]

in 4th gear... on a straight, a newbie to riding, but had the confidence to try a little more than 70- 80 kph, at full throttle all I get was just over 80...

[T J Crunch]

ok, thanks, I was tempted to have a go at cleaning the carb myself, have done it a few times on old cars, but it has been awhile... not sure if I would need new gaskets...

[jellywrestler]

in 4th gear... on a straight, a newbie to riding, but had the confidence to try a little more than 70- 80 kph, at full throttle all I get was just over 80...

if it's from Featherston there's likely half a kilo of methamphetamines jammed either in the fuel tank or tool box, take that ou and it will have a better power to weight ratio...

[T J Crunch]

if there was some speed in the tank it should go faster ??

[Akzle]

down hill. with a tail wind.
and have beans for lunch...

[haydes55]

in 4th gear... on a straight, a newbie to riding, but had the confidence to try a little more than 70- 80 kph, at full throttle all I get was just over 80...

How fat are you?

Yea na, no more piesies for you.

But seriously I'm almost certain gn250s have more than 4 gears. Unless the vintage ones are different (I thought the design stayed the same hence the cost of them).

[Captain_Salty]

Yea I thought my 86 had 5 gears, but was a while ago now. TJ does your GN have the gear indicator lights?

[fridayflash]

i had an '82 a couple of years ago, def a five speed, i went one tooth down on the front sprocket from stock
giving it lower gearing and enabling it too pull harder in top, was always good for 125/130kph
as previously recomended, clean carb, fresh plug and check/set valve crearance
easy stuff, you wont need gaskets for carby

[Transalper]

Clogged or stuffed air filter could be another issue to check too.

[unstuck]

if there was some speed in the tank it should go faster ??

Only if it is fresh, that shit will slow you down if its been in the system for awhile.

[GDOBSSOR]

in 4th gear... on a straight, a newbie to riding, but had the confidence to try a little more than 70- 80 kph, at full throttle all I get was just over 80...

In 5th gear, it should do 110kph at full throttle, more if you're a confident rider (albeit not for sustained periods of time). If you're not an experienced rider, try getting someone who is experienced to give it a decent road test. If it's still not right... Clean the carb, make sure the clutch isn't slipping, make sure your drive chain/sprockets are adjusted and in order.
To the person who asked whether the vintage ones are four or five speeds... Mine has five gears.

[ducatilover]

I imagine the carb will need a proper clean. A new plug, and check the valve clearances.

Yup.
I may be able to help out early this week if I get time and I have two GN carbs for parts somewhere in my garage and a few other bits floating around

All GNs are 5 speed