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Fuel pump

Posted: Sun Mar 08, 2015 4:59 pm
by Timbot1
Hi all,
I'm new to the forum and a new FZR400 owner (well the Mrs is!) anyway I've only had the bike a day or 2 and it seems it has issues. First thing was an issue after the bike had got up to normal temperature whereby when coming to a junction and stopping when you pull off the power was gone and bike would stall. Second issue happened today fuel pump started to make a lot of noise when priming and now nothing won't start or even turn over :cry: Not sure if the 2 are interconnected ???? But rather pee' d off as the Mrs can't ride it now.
Any help or guidance would be greatly appreciated. Thanks in advance.

Re: Fuel pump

Posted: Sun Mar 08, 2015 5:30 pm
by willandrip
Take the tank cover off then the fuel tap handle (there is a X head screw holding it to the tap shaft. Do not be tempted to forego this, you will regret it when you snap the tap/handle.)

Undo the supply to the carbs,remove the tank and undo the pump feed plug , the pump should be underneath on a bracket.
Check the supply filter,refit the power supply plug and run the pump outlet into a container.
Check the main supply and reserve work.

It may be the battery is now flat if you have been chowing on trying to start it.
When you say it wont turn over.... make sure it is not hydrolocked with fuel.
If so, then the float valves/height require adjustment/replacement.

Make sure the pipes are correctly routed on refitting.
If generic fuel pipes have been substituted they kink and prevent fuel supply when the motor gets hot.

Re: Fuel pump

Posted: Sun Mar 08, 2015 5:45 pm
by willandrip
You didn't get sick already did you ?

http://www.ebay.co.uk/itm/Yamaha-FZR400 ... 20f7e50606

Re: Fuel pump

Posted: Sun Mar 08, 2015 6:04 pm
by Evilchicken0
That's a shame because to me it sounds like it ran out of petrol or was going onto reserve
Easy fix indeed

Re: Fuel pump

Posted: Wed Mar 11, 2015 8:30 am
by Timbot1
Thanks for your replies both. Bike now running again but also picked up another fuel pump on ebay jyst in case. Still have the issue of loss of power at low revs which is a lot more concerning. Going to try the easy stuff first with a service etc as on closer inspection looks like it hasn't had one for some time. Also looks as though exup valve has been removed complete but as mentioned and a larger viper can fitted. So on that basis I am not sure if the cards will need balancing and/or re jetting. Looking around this forum and others it seems that these symptoms are common.

Re: Fuel pump

Posted: Wed Mar 11, 2015 5:57 pm
by Evilchicken0
If the exup has been taken out then you'll find it a bit gutless at low revs and the viper can isn't going to help that.
Balancing the carbs will always help and if it's running standard carb settings then the idle jets will probably need changing. Somebody might have an exup valve somewhere or even some rotten pipes with one in. Refitting the valve is probably better than rejetting. If you have an exup then the can only makes a difference above 8k rpm and then it's more the downpipes not the can that restricts the gases

Re: Fuel pump

Posted: Wed Mar 11, 2015 11:34 pm
by Timbot1
Thanks I think I may explore the carb route first as I would need to source everything to reinstate the exup valve and there's no guarantee that will solve the issue let alone using parts that a getting on a bit.
Thanks for the advice it's been very useful.

Re: Fuel pump

Posted: Thu Mar 12, 2015 10:01 am
by Evilchicken0
If you really can't get on with it, you can put a 3he 600 engine in. You can use a K + N filter in the airbox, there's no performance gain but they're washable.

Re: Fuel pump

Posted: Thu Mar 12, 2015 5:01 pm
by Wraith
Picking up another Exup Valve should be pretty easy as there are plenty of rotted header pipes about.

Reinstating the Exup WILL def help sorting out the No Low End Power

Exup is normally only removed by people using bike for Track Days (No need for low end power)

Re: Fuel pump

Posted: Thu Mar 12, 2015 9:26 pm
by Timbot1
Replacing the exup is out of the question as the cover has been welded back over where the valve was. A different engine is a bit extreme at the moment as is not a case of living with it and lack of power there is no power if the bike has idled for a bit say at a junction so once service is done at the weekend hopefully! Will explore the carbs but will probably get that done by a professional if I can find someone local.
Thanks again guys :grin: