GZ250 hard to start

[GZ250]

Hi guys,

First post here..

Recently picked up a gz250, I love it! - and since im on my learners it's as big of an engine as I can get for now.

It's in great condition, and apart from the rear brake having a loud squeal the only issue at hand is starting the sexy red beast.

It simply doesn't start from cold without a fair number of attempts (maybe 20+).
Even with the choke on full it still wont start. I've checked the idle adjuster and tried all positions the choke can do across the range and it still wont start and stay running.
It turns over, then after one or two seconds it dies.

Once it finally is running, it has a rough idle till its warmed up a bit. Then its mint.

I can restart it straight away if its turned off, even up to a few hours.
But once its completely cold, its hard to start again.
It's garaged and its not too cold in Auckland at the moment either.

Any ideas?

Also, as lame as it sounds the rush from taking a bike up to 50kph for the first time is quite amazing!

It has the same engine as a GN250, so I assume the solution between bikes would be the same

[j_redley]

Theres a few things you can do here. Check the compression when the motor is cold, and again when its hot... If you dont have a compression gauge, try starting it with a can of start yah bastard when its cold. If it starts first try using that would tell you the compression is low and the motor is getting tired....

Could also pay to check the carbs... couple of jets might be blocked up.

[_STAIN_]

don't open throttle while cranking

[Gibbo89]

Also, as lame as it sounds the rush from taking a bike up to 50kph for the first time is quite amazing!

wait till you add another cylinder, or 3

welcome to kiwi biker.

hope the bike gets going well again soon

[GZ250]

don't open throttle while cranking

I assure you there is no throttle at idle, I realise given the way it functions how pointless it would be

[GZ250]

Theres a few things you can do here. Check the compression when the motor is cold, and again when its hot... If you dont have a compression gauge, try starting it with a can of start yah bastard when its cold. If it starts first try using that would tell you the compression is low and the motor is getting tired....

Could also pay to check the carbs... couple of jets might be blocked up.

If there is a wide range of compression across the board from hot and cold, would that mean its best to replace or repair, or leave the engine be as it is?

How many jets are there and how could I tell if they are blocked? - also how to clear them up?

[breakaway]

Check the simple things first.

Next time when you try to start it from cold, crank the choke on full, as far as it will go, and hold down the starter until it runs. It should start and start idling at about 3-4000 rpm or higher.

Perhaps you just haven't gotten the starting procedures down. There's a trick to starting every bike.

[imdying]

Perhaps you just haven't gotten the starting procedures down. There's a trick to starting every bike.

What he said. Don't panic till all else fails. For example, some bikes absolutely will not start if you even dare look at the throttle before it's running (and others like you to blip it as you crank etc etc).

[j_redley]

If there is a wide range of compression across the board from hot and cold, would that mean its best to replace or repair, or leave the engine be as it is?

How many jets are there and how could I tell if they are blocked? - also how to clear them up?

ok, what everyone else said first... then start looking at compression.

If there is a wide range between cold and hot, then it depends on you and money and everything else as to what you do. Personally seeming as I'm in the mechanical trade, I'd look at replacing the rings myself. For those who arn't, I don't know how economical it is to do so. How many k's has the bike done?

If you do take the carb's off, I think there's either 3 or 4 jets in them? Easiest way to clean is with compressed air.

But like everyone else said, full choke and crank till it starts first, and check air filter restriction...

[molex]

Try ask them :

http://www.gz250bike.com/forum/

[The Everlasting]

Yep definitely stay off the throttle,even if it seems like it's not starting,I used to apply some throttle when trying to start it,and I ended up just killing the battery.

[FROSTY:Me]

Its based on the GN innit? Ok I'd like to propose you try something totally different.
With the engine in the non starting state connect a set of jumper leads from a car battery to the bikes battery and try starting the bike as you have in the past.
You either will or wont notice the difference straight away. Ie the bike will fire up within 5 seconds or so or it wont.
If it does fire up right away then I'd suggest you may be coming up due for a new battery and its dropping amps as it sits for awhile.
Also I'd suggest your starting method may be wrong. Try this seperate from the above idea I'd try 1/2 choke and about 1/8 throttle when you push the button. I could be totally wrong on the throttle front mind you