FZRSupport: the FZROnline Archive

Hi

I have put brand new spark plugs in my Yamha FZR 400R Deltabox, aswell as a brand new airfilter, antifreeze coolant, Carb cleaner in the tank, i dont know too much about bikes so havnt checked out everything, however with all this my bike is still not starting it will not even run start, the battery did go flat however i put battery acid in and the multimeter read 12.56volts however it still wont start, i am on the brink of sending the motorbike i to the get compression checked and the carbs and injectors cleaned reset and rebalanced as this seems to me to be the only thing left to try?? any idea's??

Thank you would help aloy.

Use your multimeter and start checking your connections. There's a wiring diagram somewhere here for a 400.

It seems to me 12.56 sounds low, I might be wrong. But I thought you needed more like 14 volts...... for cranking power.

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Ok - Lets take this from the top

The engine cranks over ? if it doesn't then the kill switch is set to "off" or the bike's in gear (neutral light ?) or side stand cut out isn't working
It sounds from your post that it probably does crank over though. So your battery sounds a bit low - recharge it over night and it should read about 13-14volts. If it's just 12 then it's a bit low and you might want a new one, the engine will turn over but a bit slowly. You can put some jump leads on it then try.
Next up - you've got new plugs in so they should be ok pull one out and put it on the engine block then turn the engine over to see it spark.
Now you need a can of carb or brake cleaner. Take the tank and airbox off the bike. You'll see the carb intakes gently lift them up a bit and squirt some cleaner in there (3-4 seconds) do that to all 4 carbs, choke half open but no throttle. This is to check fuel flow - if the bikes runs and then dies it could be the fuel tap is "off" or "on" when the petrol is at reserve level.
If this doesn't work then I'd suggest it's the valve tollerances. As the engine gets old the valves get longer until they eventually touch the camshafts and the engine looses compression - so you were right when you said next was a compression test. Has the bike been getting harder to start ??? If the engine is warm toough the head will expand just enought to close the gap and the engine may fire on three then four but then it will return to being a dog to start.

Never add acid to a battery; if your electrolyte levels are low, add distilled water. Try charging your battery, but I think you've screwed up the SG.

Valve clearances tighten up not because the valve stretches, but because the hard valve pounds itself into the softer head. Also, the valve 'tulips' or distorts under heavy use, sinking further into the head.

Yeah, I'm not sure even if his engine cranks on the starter or not....

Can we get a clarified OP?

"still not starting it will not even run start"

If the sidestand is down you must engage the clutch to create ground for start, if it is similar to 600 logical circuit.

Not if it's in neutral.
If you need to do pull the clutch in to start the bike (in neutral on the stand) then the neutral switch is dodgy

Good catch. That's correct.