FZR 250 floods and cuts out when taking off?

[SHapeshifter]

Hey there i recently got a FZR 250 and im having trouble with it heres the story...

Starts fine in the mornings and when ever the bike is cold i just give it the tiniest bit of gas and it starts right away.

But once its warm and been riding it a bit and I turn it off for 10+ or so minutes when its started again it wont rev and if i let go of the throttle it just dies, the only way Ive been able to get past this is revving it as low as possible until it sounds like it wants to go again then i stab the throttle and rev it quite hard and it seems to be good as new again.

I have also noticed sometimes when taking off the bike does the same thing again and refuses to go faster than walking speed (very annoying at the lights and roundabouts etc...) i then have to pull over and redo the revving thing all over, although it doesn't take nearly as long as when its been sitting for a bit

Ive looked all over the net and these forums but the only thing i can find is that its either the carbs or the fuel pump but i really don't have any idea what the problem could be, and i dont really want to pay a heap of cash to get everything looked at

Any help or suggestions would be great!

[CookMySock]

Is the inside of the exhaust pipe real white or real black?

Steve

[SHapeshifter]

Rubbing my finger along the inside of the exhaust turn out very black, what does that mean? i thought it would be normal for there to be stuff inside it.

[The Pastor]

hmm unforuntaly the nick name for the fzr250, fizzer is well justified. Just are lemon bikes mate.

I think the fzr has some kinda of "exup" exhaust valve. From memory they are prone to failure.

I'd start buy checking the spark plugs and air filter - unlikely to be sole proplem, but a clean air filter and plugs go a long way to making things better.

Then i'd find out about the exup valve. I dont know to much about them, but someone on here will.

If its not the exup exhaust valve, it'll be the carbs - to get these looked at (and dont expect them to be fixed first time, there are lots of things that could be wrong with carbs and you never know) cleaned and balanced - i'd say about $200 from a good shop.

[SHapeshifter]

Well i can definitely rule out EXUP valves because i know my "87 model was made without them, only the "88 version and up came with it

[CookMySock]

Rubbing my finger along the inside of the exhaust turn out very black, what does that mean? i thought it would be normal for there to be stuff inside it.

When its giving you problems, does it blow any smoke from the exhaust? What colour is the smoke?

It sounds like lots of fuel in the wrong place, but all the carbs are doing it together - not just one. Does it do it only with a full tank of gas, or with any level of fuel in the tank?


Steve

[SHapeshifter]

When it is having its little moment it blows white smoke, its not very bad but when it idleing/revving normally it makes none

Also seems to make no difference how much fuel is in the tank but i dont really think about that when it is doing its thing so cant be certain

[CookMySock]

Ok I wonder if you have a head gasket problem. That sounds like water vapour to me. It might be fuel yet. That is all I can think off at the moment. Let some other KB'ers comment before you do much else. There is a gadget that can be put on the water-cooling system to tell you if there is combustion gases in the coolant. Does it use any water? Can you take the radiator cap off (cold engine only!) and start and idle it and see if it blows bubbles? If it doesnt blow bubbles, give the throttle a wee blap and see if it does then.

Steve

[SHapeshifter]

Ok I wonder if you have a head gasket problem. That sounds like water vapour to me. It might be fuel yet. That is all I can think off at the moment. Let some other KB'ers comment before you do much else. There is a gadget that can be put on the water-cooling system to tell you if there is combustion gases in the coolant. Does it use any water? Can you take the radiator cap off (cold engine only!) and start and idle it and see if it blows bubbles? If it doesnt blow bubbles, give the throttle a wee blap and see if it does then.

Steve

By using water do you mean radiator fluid? It doesn't seem to be blowing any bubbles even when revved and the radiator still seems very full.

[Dargor]

Are you using the choke to start it. If bike is warm, Dont.

[SHapeshifter]

Are you using the choke to start it. If bike is warm, Dont.

Never had to use choke hot or cold, starts perfectly its just the whole not revving thing that is the problem

[98tls]

Bloody hard without being there but possibly a sticking float as in its flooding.Then again if its only going pear shaped when hot it could be the likes of coil breaking down.

[CookMySock]

By using water do you mean radiator fluid? It doesn't seem to be blowing any bubbles even when revved and the radiator still seems very full.

Ok it seems that white smoke is more likely lots of fuel. Does the bike have a vacuum fuel tap or a vacuum operated fuel pump? If it does, I wonder if it has a hole in the diaphragm.

Steve

[SHapeshifter]

Umm how would i find this out? Not really the best when it comes to engines

[CookMySock]

You really need a parts manual for it, or else just pull the tank off and have a look.

Let someone else comment also. I don't know that bike exactly.

Steve