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Fuel Pump don't get it?

Posted: Wed Oct 26, 2011 9:12 pm
by MarkT
Ok, Old fuel pump would not stop click when turning ignition on so after checking fuel supply from tank and looking for flooding replaced it with one from eBay.
New one just the same? After I fitted it I used the engine stop switch on and off for about 2 mins and it was just clicking, if I moved the reserve switch it would keep clicking aswell if it was pumping into the carbs it would have been well and truely flooded by the amour that gets pumped out without the pipe connected to the carbs!!

After two minutes were up choke on press start and I get a normal statup with no signs of flooded smoke. Rode bike for about a mile and stopped and tried again. Only one click even when I used reserve etc. Bike went great on my 30 mile run and had a great time. Stopped for a coffee about half hour, got back on no click from pump, started straight away and drive home, great ride again. Parked while I opened garage door started in no clicks and put it away.

This is exactly what the old pump did! First start from cold doing the above test was the same and I could leave it to warm up with no probs bu could not hear if the pump was clicking or not cause of the noise of the engine.

Just to clarify the fuel pump when starting cold times out and does not keep running.

Now I have a spare fuel pump there is definitely no flooding and fuel supply from tank is good, you can see fuel in filter so is this normal when the pump is cold? I know I should lift the tank and block the pipe to carbs and see if it still does it but I am sure it will be the same. I am so tired of the amount of times I have had to remove the tank since I had it with all the old carb problems I thought I would see what the experts say! With my engine setup I don't think the bike could run better without a dyno session but the pump clicking in 10 second bursts all the time is puzzling to me?
Mark

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 1:08 am
by Morespeedvicar
Hi, sometimes my 3en1 fuel pump keeps running when the engine is hot, its ok when its cold and only runs till the carbs are full, but when the engines warm it sometimes keeps running, and like yours theres deffo no signs of flooding. I always just thought it was one a them things they do!?
Cheers
Ian

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 6:26 am
by MarkT
Thanks Ian, as I say the bike runs great and I have plans to take it abroad next year!! It's really bugging me but I don't want to take it apart again but there is defiatley no flooding?
Cheers
Mark

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 9:47 am
by Evilchicken0
If there's no flooding then maybe the feed isn't as good as you might think. Do you have a bottle that's translucent you can fill with petrol ???
Put a longer hose into the petrol and run the pump (from cold) it it take the same time to prime then there's not much you can do. If it's significantly shorter then it's a fuel flow problem. Check the filters aren't clogged, theres one on the fuel tap, the inline one and one where the fuel pipe joins the carbs.

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 10:36 am
by MarkT
Thanks mr EC apart it will come again!! How do you clean the one in the fuel tap? Why do you think it is ok when warm?
Thanks

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 11:07 am
by MarkT
I just went out to try it and lo and behold you heard it prime straight away, about 1 1/2 clicks! I tried it on the slope as I know it is low on fuel and it was fine again! I shall have to see what happens next time! I would still like to clean fuel tap though?

See mr EC you have had so much input into fixing it you are know doing it remotely! Lol

Also all the priming issues were straight away after fitting the pump? Air bubble?

Mark

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 12:44 pm
by Evilchicken0
If it's straight after fitting the pump then it's the pump filling itself with petrol. Now it's filled and primed it should be ok.
You worked on Yam 2 strokes before remember those 350 YPVS carbs had a "prime" on them ... that's probably what hppened to your 3TJ. The fuel filters should be fine now but for fuel tap filter just turn the tank over and unbolt the tap - the filters on top. Best to wait till your on reserve ;)

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 2:39 pm
by MarkT
Yes I remember! Keep fingers crossed that all is ok now

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 2:54 pm
by MarkT
Thinking about it though this is what the old one did which is why I changed it? Mm mn i really don"t know if I have got to the bottom of this. If it happens again I will have to check fuel flow as it was really about 2 mins it was timing out and you could see fuel and a bubble in the online filter?
I guess all I know now that it was ok overnight and everthimg was full with fuel today!
Mark

Re: Fuel Pump don't get it?

Posted: Thu Oct 27, 2011 3:22 pm
by MarkT
Just checked with Fowlers , no filter in the tank just the one by fuel pump £14.00. new tap is £28 and both in stock ! I can but keep a eye on it. Cheers EC!