tzr 50 keeps breaking down?

tzr92 · Derestricted Danger Joined: 29 Mar 2009 Karma :

I have a 2003 tzr 50 and my bike has recently broke down. When I take the bike up to 9000+revs it starts missing a lot and it holds back as i cant take it over 10000 revs. It does it most of the time but recently when it has started cutting out all together and the revs just drop until I stop and after that it is hard to start. the starter motor turns the engine over but it wont start. It will eventually start after 5 mins or so until it breaks down again. I realised when it started missing and i put the choke on it suddenly pulls away so i looked for air leaks on the manifold but there was none. Can someone help please.

I have already changed the spark plug, plug lead, the coil and I have checked and cleaned out the carbuerator and connectors for the coil.

I tried a colour tune in it and it was still sparking when it cut out but not igniting so I dont think it is getting enough fuel. I am going to try another carbuerrator at the weekend. If it is not that I think their might be an air leak inside the crankcase.

Does anyone have any other ideas that I could try as I was not wanting to open my engine up

tzr92 · Derestricted Danger Joined: 29 Mar 2009 Karma :

No one have any ideas

Faraz · Nearly there... Joined: 26 May 2007 Karma :

Exact same thing was happening to mine.

Have you done any "mods" recently?

I moved the clip on the carb needle to the top. Mines is working fine now.

This was after a 70cc bore kit, technigas exhaust and a 110 jet.
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tzr92 · Derestricted Danger Joined: 29 Mar 2009 Karma :

I have not done any mods but its derestricted. Might have happened with you because you put a new jet in and didnt tuen the carb to fit the new jet and big bore kit.

tzr92 · Derestricted Danger Joined: 29 Mar 2009 Karma :

could it cut out if their was a leak in the crankcase?

baldy · World Chat Champion Joined: 15 Feb 2004 Karma :

Are you sure that when you turn the choke "on" you are not turning it "off"? Is there a chance that you got the settings mixed up? It sounds like a fueling problem, but when you said the choke made it better, it gave me the idea that on is actually off if you know what i mean.
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tzr92 · Derestricted Danger Joined: 29 Mar 2009 Karma :

Im sure the is in the right position as the bike used to run fine before and it has an on and off position. That would also mean I have to switch the choke off to start it on cold days lol. I know I have the choke the right way.

It means the mixture isnt right if it goes better with the choke on. So it must be too little petrol or too much air. I dont know what would cause this as I have checked fuel flow and checked for air leaks in the manifold