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ER5 Fuel system issue


M4man
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When I the bike the sump was full of fuel. As the fuel tap was left on "prime" I assumed that was the problem. Drained the crap, changed the filter and refilled with new oil. Then noticed all fuel lines to the petcock were disconnected or removed. Haynes doesn't make things too clear so I had to work it all out. Put a couple of litres of new fuel in the tank and she fired up first time. Settled down when warm and ran sweet. Noticed a leak from the "out" on the petcock so put a new one on and put a few more litres in the tank. All went well for about 5 mins then she cut out and won't restart. Noticed fuel leaking out from the bottom of the RH carb. Any ideas?

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When I the bike the sump was full of fuel. As the fuel tap was left on "prime" I assumed that was the problem. Drained the crap, changed the filter and refilled with new oil. Then noticed all fuel lines to the petcock were disconnected or removed. Haynes doesn't make things too clear so I had to work it all out. Put a couple of litres of new fuel in the tank and she fired up first time. Settled down when warm and ran sweet. Noticed a leak from the "out" on the petcock so put a new one on and put a few more litres in the tank. All went well for about 5 mins then she cut out and won't restart. Noticed fuel leaking out from the bottom of the RH carb. Any ideas?

 

Yep . This is SO typically ER5 I've almost lost the will to explain it all over again . But just for you , here we go . Firstly none of this could happen if the fuel tap was reliable but it isn't . There is a microscopic hole in the plastic plate between the two diaphragms that gets easily blocked causing the tap to stick open . Poke it out with a very very fine wire and it will work for a while . The best cure is to chuck it away and fit one off an RF 900 ( there are other options but I can't remember them right now ) Now the main issue. There is no reason why ER5 float valves should be any more likely to stick open than on any other bike but they do . They just do . The cause is dirt and this is usually because one or both of the filters inside the fuel tank has simply rattled out of its housing on the back of the nozzle . The best cure is to junk both of them and replace with one big inline filter between the tap and carb . You are going to have to whip the carbs off and turn them upside down, remove the float bowls and blast carb cleaner back down the float valves ( floats and needles removed ) in order to dislodge the dirt . I hope this helps . One other thing you could do is register on the ER5 Forum by Bikers Oracle ( sorry Stu ) Then there will be five active members including myself ( Earlsdon ) but you will have access to dozens of threads dealing with your current problem. Don't lose heart , these bikes are a little cracker when they are sorted .

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  • 3 weeks later...

Update. Remove carbs, cleaned and replaced needle valves, pilot jet and float chamber gasket. Removed fuel filters, cleaned and blew the pipes through. Changed the oil and filter (again!). Started first time and ran well. Left alone for a week due to work commitments and it's overfuelling again! Just out of interest, how many turns on the pilot jet?

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Update. Remove carbs, cleaned and replaced needle valves, pilot jet and float chamber gasket. Removed fuel filters, cleaned and blew the pipes through. Changed the oil and filter (again!). Started first time and ran well. Left alone for a week due to work commitments and it's overfuelling again! Just out of interest, how many turns on the pilot jet?

 

Here you go , I think mine are at one and a half turns out but bear in mind this only really has an influence on idle and slow running. Could I suggest that you replace the black rubber fuel pipes with some PVC ones . This is not a new bike and old age combined with modern petrol may well be the cause of the rogue particles that are interfering with the correct operation of the float valves . Mine hasn't flooded once since I carried out this simple modification . Have you looked at or joined the ER5 Forum yet ?

PhotoEditor_20190806_005257100.thumb.jpg.bf281ad145069599a78afdd320db9716.jpg

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Sorry to jump on the thread but does anybody know if the tank has a BSP thread or is it metric?

 

Never heard of BSP . Do you mean the two brass fuel outlets ? They must be metric because I've got a spare one that I used to make a dummy fuel tank for carb balancing and I had no trouble finding a nut to go on the back .

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British standard pipe (BSP) I was asking as I have some BSP fuel taps from years back.

As the bike is Jap made most of us think it would be metric but worldwide BSP hasn't died out yet.

I have worked on Hitachi excavators with British threads.

I have an ER5 I am starting to refurb but cant get to it yet too much junk in the way. john.



https://en.wikipedia.org/wiki/British_Standard_Pipe

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British standard pipe (BSP) I was asking as I have some BSP fuel taps from years back.

As the bike is Jap made most of us think it would be metric but worldwide BSP hasn't died out yet.

I have worked on Hitachi excavators with British threads.

I have an ER5 I am starting to refurb but cant get to it yet too much junk in the way. john.



https://en.wikipedia.org/wiki/British_Standard_Pipe

 

Oh , I thought you meant the threads on the back . Well if it's a snug push fit it doesn't really matter whether it's metric, BSP or whatever . If you are referring to the tap itself , it doesn't fit to the tank . It bolts to the frame and is fed by two pipes .

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Not seen the bike for some years so had forgotten how the carbs are fed.

I was thinking the original tap that gives trouble could be unscrewed from the tank and replaced with a simple on/off tap.

Thanks for explaining john

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Thanks for this. I'll have another go. Yes I've registered with the ER5 forum

 

Can't see you. Have you posted anything yet ? Is it the Biker's Oracle site ?

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Registered but can't access Bob. Any recommendations for sourcing a plug spanner that will fit an ER5?

 

It's down right now . I'll check what spanner tonight .

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Registered but can't access Bob. Any recommendations for sourcing a plug spanner that will fit an ER5?

 

It's down right now . I'll check what spanner tonight .

 

It's an 18 mm hex that you want but there isn't much space down there so you need a thin walled box spanner . Like this .

Screenshot_20190812-225112.thumb.png.6d34ea6ff32f67ba7507d4cd5a3a1de7.png

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  • 1 year later...
On 20/07/2019 at 19:43, M4man said:

When I the bike the sump was full of fuel. As the fuel tap was left on "prime" I assumed that was the problem. Drained the crap, changed the filter and refilled with new oil. Then noticed all fuel lines to the petcock were disconnected or removed. Haynes doesn't make things too clear so I had to work it all out. Put a couple of litres of new fuel in the tank and she fired up first time. Settled down when warm and ran sweet. Noticed a leak from the "out" on the petcock so put a new one on and put a few more litres in the tank. All went well for about 5 mins then she cut out and won't restart. Noticed fuel leaking out from the bottom of the RH carb. Any ideas?

I had this problem many times , I discovered the manufacture forgot to put the filters in the tank, I had to fit an external filter, which  was much cheaper than the internal ones. the other problem was fuel getting into the engine. this was prevented by inserting a piece of fuel pipe up the bottom of the filter where it attaches to the engine. about a couple of inches long. and sealed in. this still allows the breathing, but the fuel can't get into the engine if the problem re occures , it will just leak out the drain holes at the bottom of the filter .

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  • 2 years later...

Hello everyone!

 

So I had fuel tap issue and my engine over flooded. So i did take of my fuel tap and took it to service they checked it and said they fixed it. But how can i make sure its fixed and not gonna flood my engine again? So im thinking of puting new oil and filters but im afraid its gonna overflow my engine and waste my new oil again. 

What can i do to check it? 

 

Sincerely, Mareks 

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Why would a fuel tap flood your engine, a fuel tap is either open or closed, it's the carb which allows the passage of fuel. Sounds more like a stuck float but as you don't say what bike you have that is purely a guess.

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This was a problem with vaccum taps when they fail they are a pain in the neck. Hopefully a service kit has fixed it but its worth making sure the float valves are seating properly and sealing off. Make sure the airbox drain is clear to and another mod others have done is the vent that comes from the engine enters at the bottom of the airbox remove it block the hole up, then get a longer pipe and drill a suitable hole higher up and fit the vent pipe here. A short cut is remove the pipe all together from the engine and fit a small pancake filter. A sure way to fix the problem is fit a fuel tap that you have to turn on and off and if I remember right the tap off a Suzuki RF600/900 is a straight swap and mounts on the frame fixing.

Edited by Old-codger
spelling doh
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7 hours ago, Yorky said:

Why would a fuel tap flood your engine, a fuel tap is either open or closed, it's the carb which allows the passage of fuel. Sounds more like a stuck float but as you don't say what bike you have that is purely a guess.

 

Basically the tap is vacuum activated, but it fails and allows petrol to the carbs. The OEM float valves seem to be total crap, as they often leak and let fuel past them. Although from my anecdotal experience, it only let 2/3rds of a tank, so it seems to be a pressure related issue. I replaced with non-OEM valves that looked a bit more substantial than the stock ones, and so far it has been happy days. The tanks filters come away very easily as well, so any sediments clog things up on the line. I've fit an inline filter on my project bike, and I need to fish out the filters at some point as they rattle around when the tank is low.

 

@Mareks If they say it is fixed, I would put it back on the bike and fill up the tank from a jerry can. Say about 5 litres at a time, and leave it with the fuel tap set in the on position for several hours. I'd prime it first for a minute to let the carbs fill up, just to prove it won't spill out into the engine, then leave it in the on position. Keep an eye on the oil level glass on the side of the engine. If you don't see any petrol in there, fill up another 5 litres and wait again. If you get to a full tank and there's no problems, I'd take that as a good sign you are in the clear. I'd also crack open the oil fill point and sniff for petrol before you start, and if it gets much stronger that suggests some is still getting in. 

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