My FZR 400 doesnt like starting, sometimes it starts no problem, but most of the time it just doesnt want to fire.
When it does start i need to hold throttle half open for it to idle, any more or any less it just cuts out. It clears after a while of holding it at tick over, tonight it was running on 3 and then suddenly started running on 4 then went back to 3, it runs ok after 4 thousand revs.
Just wondering if anyone could help me?
Thanks.
Doesnt like starting.
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0G0R3K-15
- Settled in member
- Posts: 64
- Joined: Wed Jun 09, 2010 9:41 pm
- Bike owned: Yamaha FZR 400 Genesis 1986
- Location: Sunderland Tyne & Wear
Re: Doesnt like starting.
What's the condition of spark plugs? i had almost the same with mine and replacing spark plugs helped.
btw, replacing them is a disater as u need o take radiator off. And the access doesnt help
btw, replacing them is a disater as u need o take radiator off. And the access doesnt help
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Evilchicken0
- Site Supporter
- Posts: 5374
- Joined: Tue Apr 29, 2008 8:59 pm
- Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
- Location: Lundin Taan
Re: Doesnt like starting.
Do you know the model of FZR ???
Sounds to me like it's the valve clearances. As the engine spins at up to 14.5k rpm the valves get hamerred into the head ... well you can guess how many times it happens over a few thousand miles. Anyway the valve stems stretch and eventually touch the camshaft so they don't seal to the head and the bike doesn't run until it gets warm. Then the metal expands just enough to get a seal and it fires.
It's curable though you just need the valve clearances done.
Bad news is this is time consuming so if you take it to a garage expect to pay about £300.
To get a better indication you need to compression test the engine. If you get low or no compression on the first test add some oil to the cylinders, if it doesn't help it's probably the valves, if the compression goes up then it's probably the piston rings.
If you've got some experiance with the spanners get a copy of Practical Sportbike there's a how to guide with pictures have a look and see what you think.
Sounds to me like it's the valve clearances. As the engine spins at up to 14.5k rpm the valves get hamerred into the head ... well you can guess how many times it happens over a few thousand miles. Anyway the valve stems stretch and eventually touch the camshaft so they don't seal to the head and the bike doesn't run until it gets warm. Then the metal expands just enough to get a seal and it fires.
It's curable though you just need the valve clearances done.
Bad news is this is time consuming so if you take it to a garage expect to pay about £300.
To get a better indication you need to compression test the engine. If you get low or no compression on the first test add some oil to the cylinders, if it doesn't help it's probably the valves, if the compression goes up then it's probably the piston rings.
If you've got some experiance with the spanners get a copy of Practical Sportbike there's a how to guide with pictures have a look and see what you think.