Ninja 250 coolant leak.

[Benq]

Hi everyone. I recently just bought my ninja 250 2008 and it has a problem. It died on my yesterday and it started fine after I jump started it but after a few minutes the rpms were reving very high, close to 9000 rpm without me touching the throttle. Then it started leaking all over the ground so I shut the bike off. Does anyone know what the problem could be? I'm new to bikes so don't have an idea yet.

[Triple Jim]

Welcome to the board, Ben.

The coolant leak may be from overheating, from revving to 9,000 rpm on a hot day without the bike moving, causing it to lose coolant out the overflow tube.

As far as the revving, with the engine off, see if you can find something that made the throttle cable or linkage stick. Other possibilities are things like the carb slides (internal carb parts) sticking up.

[Benq]

I didn't rev the bike myself however. It was in neautral warming up when it started reving by its own. But I'll defiantly check out the other things you mentioned. Thank you.

[Alex]

/moved to new-gen tech area

[DannoXYZ]

Welcome Benq!

You've got multiple issues.

First is warm-up and choke operation. Turn choke ON to start, then gradually turn OFF as engine warms up and idle-speed increases. Does it rev to 9000rpm with choke OFF?

next is cooling system related. Cooling system is sealed, meaning it's like a milk-jug, you can tip it upside down and fluid stays inside. If stuff inside is getting to outside, there's hole somewhere. When coolant is leaking, where is it coming from? Get a bright flashlight and trace path of coolant from ground up to source.

Third is radiator fan and thermoswitch. When coolant gets hot enough to leak, is the radiator fan coming on?

These additional details should help you track down the problem and fix it. Take pictures and post them here to help with diagnosis.

[Triple Jim]

Originally Posted by Benq

I didn't rev the bike myself however. It was in neautral warming up when it started reving by its own.

I understood that, and didn't mean to sound like I thought you did it on purpose.

[Benq]

Haha its okay

[KikRox]

Originally Posted by Benq

Hi everyone. I recently just bought my ninja 250 2008 and it has a problem. It died on my yesterday and it started fine after I jump started it but after a few minutes the rpms were reving very high, close to 9000 rpm without me touching the throttle. Then it started leaking all over the ground so I shut the bike off. Does anyone know what the problem could be? I'm new to bikes so don't have an idea yet.

two unrelated issues. first the reving is probably an issue with your carbs, choke plunger is a target of interest other places to look are vacuum leaks. Make sure all hoses are routed right to the fuel enrichener, if you put the wrong vacuum line on the enrichiner it will *hang* if thats not it perhaps you're running lean and to find out you will need to pull a plug. your idle circuit may be dirty and just need a cleaning. (pilot jets)

coolant issue, who knows man.. you got some hunting to do, isolate where the coolant is leaking from and work your way from there. random note the oem hose clamps on the ninja are pretty crappy and strip easily so if your hoses are swollen they will end up leaking. good luck dude!

[Benq]

It's okay I solved the problem. When I start my bike I leave the choke on. That's when it started reving and leaking, I turn choke off after a few minutes of starting it and it dosent leak or idle high. Everything's good. Thanks tho

[KikRox]

But did you stop the leak? cus it sounds like once you start rocking out at higher rpm its going to p*ss coolant, and thats not good. (unless its coming from the over flow which doesnt really matter then)

[DannoXYZ]

Yeah, multiple issues. The leak is completely un-related to high-idle with choke-on. Next time engine gets hot, like trolling around in slow-traffic, it's going to spew again!