Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


Kawasaki ER5 - fuel logic!

Reply to topic
Bike Chat Forums Index -> The Workshop Goto page 1, 2  Next
View previous topic : View next topic  
Author Message

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 13:04 - 13 Nov 2018    Post subject: Kawasaki ER5 - fuel logic! Reply with quote

Afternoon all,

A long time lurker of the forum, it's proved a very useful place for information! I now have a question of my own . .

Last night my 2006 ER5 (bought a few weeks ago and I think it had been standing for a while before purchase, at least 4/5 months, maybe longer) decided to start leaking petrol everywhere when I stopped. It's been ridden about 70 miles since I got it (only got MOT'd last week) and it's been fine until then. Fortunately a fire didn't occur despite it spilling onto the header pipes with impressive quantities of smoke! Shocked

Anyway, the bike is home now and I want to try and solve the problem myself if I can. I'm new to bikes (and carb'd engines!) so I'm hoping someone can check to see if my logic is correct?

So, the bike uses a vacuum operated petcock (on/reserve/prime). The bike was leaking petrol out of the airbox (or it looked like that anyway, it was certainly further back than the carbs themselves) and continued to leak until the fuel level was sufficiently low presumably to have dropped to the high level pickup in the tank. The tank itself was lifted and was dry underneath, so the leak isn't from the tank itself or the pipework there.

First conclusion(?) - the connection between the tank and the petcock didn't appear to have any leaks, so for fuel to continue to flow past this point without the engine running must mean the automatic/vacuum petcock had failed? I will double check this by spinning it onto reserve with a can under the fuel pipe and would expect fuel to flow, even though it shouldn't as only the prime should bypass the vacuum diaphragm?

First question: if this is the case, would the carb allow enough fuel through to create the above symptoms (petrol was flowing out almost at a trickle, not quite a steady stream but not far off - it emptied about 7 litres of petrol out in about an hour)?

Second question: I'm reasonably handy with a spanner (used to work on cars, although never touched a carb) - is it easy enough to service a petcock with an eBay type repair kit and check the carbs for cleanliness?

Third (last!) question: I think it'd be good to change the fuel lines as there seems to be splits in at least one of them (although it isn't leaking, the split is on the cut end of the pipe after the sealing clamp); is fuel line just fuel line? I presume I replace the little wire sealing clamps with new ones?

Cheers all and apologies for launching into all this on my first post!
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Suntan Sid
World Chat Champion



Joined: 07 May 2009
Karma :

PostPosted: 13:16 - 13 Nov 2018    Post subject: Reply with quote

Check your engine oil, it's probably now over filled with a lovely petrol/oil mix!
Had exactly the same problem with a mates ER5, check the carb diaphragms for the tiniest hole/split.
____________________
"Everybody needs money, that's why they call it money!" Cool
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 14:48 - 13 Nov 2018    Post subject: Reply with quote

Yeah I'm going to dump the oil as it'll almost certainly have petrol in it. Annoying, only changed it on Saturday!

As for the diaphragm split, surely the petcock would still have to be malfunctioning to allow fuel out with the engine off in the first place? If the petcock was functioning correctly, no fuel should be getting to the carb with the engine off, so even if the carb is knackered (it was functioning perfectly before the leak) there shouldn't be a leak?

Now I'm on the edge of my knowledge here, but I think I'm right in saying that the carb experiencing the fuel pressure from the tank (it's effectively functioning as if it's on 'prime' if the vacuum isn't working) then it'll just fill up the bowls and eventually overflow somewhere?
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

jaffa90
World Chat Champion



Joined: 06 Apr 2016
Karma :

PostPosted: 14:56 - 13 Nov 2018    Post subject: Reply with quote

The prime is to fill the carbs up after evaporation for starting when cold and then to the on position when running.
If the vacuum tap (on) part fails fuel can run down the vacuum pipe and into the inlet manifold.
 Back to top
View user's profile Send private message You must be logged in to rate posts

pompousporcup...
World Chat Champion



Joined: 15 Apr 2015
Karma :

PostPosted: 15:30 - 13 Nov 2018    Post subject: Reply with quote

Good old keihin CVK carbs.

my guess would be your needle valves have crap between the valve rubber and the seat. This means that no matter what, the fuel will still keep coming into the carb... float be damned.

fuel level increases and eventually it pisses out the intake side of the carb, into your airbox and then out of the airbox drain hole..
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 15:39 - 13 Nov 2018    Post subject: Reply with quote

pompousporcupine wrote:
Good old keihin CVK carbs.

my guess would be your needle valves have crap between the valve rubber and the seat. This means that no matter what, the fuel will still keep coming into the carb... float be damned.

fuel level increases and eventually it pisses out the intake side of the carb, into your airbox and then out of the airbox drain hole..


Surely in the case though, the petcock would have to be failing to let the fuel even reach the carbs in the first place?
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

andy_uk
World Chat Champion



Joined: 13 Aug 2011
Karma :

PostPosted: 20:39 - 13 Nov 2018    Post subject: Reply with quote

ThunderGuts wrote:

Surely in the case though, the petcock would have to be failing to let the fuel even reach the carbs in the first place?

Yeah, they're renowned for it unfortunately.
Mine failed some time ago and hydro-locked the bike...
I ended up getting a fuel tap repair kit to sort the tap and replaced the float needles on the carb as well as giving it good clean.
There is a modification you can do to the airbox to stop the fuel running in to the crankcase. Basically it involves a bit of pipe stuck in the crankcase breather hole so if it does flood again, the fuel should exit from the drain tube rather than contaminating your oil. Although...you do stand more chance of hydro-locking your engine!
____________________
Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 22:07 - 13 Nov 2018    Post subject: Reply with quote

Confirmed - petcock is letting fuel past on reserve, only a little dribble but it shouldn’t be letting anything past. Dismantled it and it’s in a state! Deposits everywhere including where the o ring seats which isn’t going to help it seal! See pic attached.

Repair kid ordered now Smile
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

pompousporcup...
World Chat Champion



Joined: 15 Apr 2015
Karma :

PostPosted: 23:37 - 13 Nov 2018    Post subject: Reply with quote

ThunderGuts wrote:
pompousporcupine wrote:
Good old keihin CVK carbs.

my guess would be your needle valves have crap between the valve rubber and the seat. This means that no matter what, the fuel will still keep coming into the carb... float be damned.

fuel level increases and eventually it pisses out the intake side of the carb, into your airbox and then out of the airbox drain hole..


Surely in the case though, the petcock would have to be failing to let the fuel even reach the carbs in the first place?


Indeed that is the case. Unfortunately for most the two issues go hand in hand.
Has happened to me before. Hydrolocked the engine. Both needle and tap were found to be at fault Sad
 Back to top
View user's profile Send private message You must be logged in to rate posts

Robby
Dirty Old Man



Joined: 16 May 2002
Karma :

PostPosted: 09:11 - 14 Nov 2018    Post subject: Reply with quote

If the fuel tap has that much crap in it, I would expect some of it to be in the carbs too. Needles and seats, and the idle circuit would be the places to definitely clean.

If they generally look fairly clean on the inside, I wouldn't worry about going much further. Petrol does a good job of keeping carbs clean, its only a problem when there's a very small hole that can get clogged up by tiny bits of crap.
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 09:25 - 14 Nov 2018    Post subject: Reply with quote

Robby wrote:
If the fuel tap has that much crap in it, I would expect some of it to be in the carbs too. Needles and seats, and the idle circuit would be the places to definitely clean.

If they generally look fairly clean on the inside, I wouldn't worry about going much further. Petrol does a good job of keeping carbs clean, its only a problem when there's a very small hole that can get clogged up by tiny bits of crap.


Yeah indeed. It was running fine though so I'll see if it's clean and take it from there. Any idea what the crap is? Almost looks crystalline! I would expect dried fuel to look more gummy rather than crystalline.
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Robby
Dirty Old Man



Joined: 16 May 2002
Karma :

PostPosted: 09:44 - 14 Nov 2018    Post subject: Reply with quote

Fuel residue does eventually turn into a mixture of brown sludge, brown grit, and greenish crystals. Bear in mind this isn't just fuel turning into strange things all by itself, but it's also carrying little bits of rust from the steel fuel tank, and little bits of alloy corrosion from the fuel tap.

Clean it all up, replace rubber bits where necessary, and it will work.

Normally at this point I would also recommend fitting an inline fuel filter, but I've had them cause problems with vacuum petcocks. The vacuum petcock works by having manifold air pressure on one side, and (uncompressible) fuel on the other. When the engine is running the low pressure from the manifold pulls the diaphragm back against its spring and lets fuel flow.
This is fine until you introduce a big air bubble on the fuel side (at the top of the filter). Then you get inconsistent pressure on the fuel side of the diaphragm, which can allow it to close up and stop the fuel flow.
Varies from bike to bike, but it can be a pain the arse to diagnose.
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 10:47 - 14 Nov 2018    Post subject: Reply with quote

Robby wrote:
Fuel residue does eventually turn into a mixture of brown sludge, brown grit, and greenish crystals. Bear in mind this isn't just fuel turning into strange things all by itself, but it's also carrying little bits of rust from the steel fuel tank, and little bits of alloy corrosion from the fuel tap.

Clean it all up, replace rubber bits where necessary, and it will work.

Normally at this point I would also recommend fitting an inline fuel filter, but I've had them cause problems with vacuum petcocks. The vacuum petcock works by having manifold air pressure on one side, and (uncompressible) fuel on the other. When the engine is running the low pressure from the manifold pulls the diaphragm back against its spring and lets fuel flow.
This is fine until you introduce a big air bubble on the fuel side (at the top of the filter). Then you get inconsistent pressure on the fuel side of the diaphragm, which can allow it to close up and stop the fuel flow.
Varies from bike to bike, but it can be a pain the arse to diagnose.


Cheers. The petcock I don't think should be affected by fuel filters as the vacuum diaphragm pulling the valve open I don't think should have any effect, as long as gravity does the job of letting fuel flow fairly freely through the filters? Intend to put a filter on both main and reserve lines before the petcock to keep that clean too
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Robby
Dirty Old Man



Joined: 16 May 2002
Karma :

PostPosted: 13:45 - 14 Nov 2018    Post subject: Reply with quote

It should already have an in-tank filter on top of the fuel tap, but they aren't very good. A proper inline fuel filter does a good job of filtering, but the air bubble at the top of the filter can cause problems with vacuum petcocks.

The vacuum petcock only opens if the pressure differential between both sides of the diaphragm is high enough to pull the diaphragm back against its spring. Air is squishy, so the air bubble in the top of the filter can allow this pressure differential to drop.

As I say, it can vary between bikes and filters, but I have had trouble with it before. If you can eliminate the air bubble from the filter you should be ok. Keeping it properly upright helps.
 Back to top
View user's profile Send private message You must be logged in to rate posts

stinkwheel
Bovine Proctologist



Joined: 12 Jul 2004
Karma :

PostPosted: 14:11 - 14 Nov 2018    Post subject: Reply with quote

Although to be overspilling your both the fuel cock has to be malfunctioning AND the needle valves in the carb need to be leaking.

It's new enough that the needle valves shouldn't be affected by ethanol. I had this problem on a mid 90's GPZ500 motor (very similar to yours) and they were jamming open. So if the needle valves are furry with white alloy corrosion, I'd replace them.

However, to a degree, it's the fuel taps job to stop fuel overspill when parked up. To quote the Bing carburettor company (who make carbs for BMW) when someone complained about leaky carbs. "We make carburettors, not fuel taps, turn the fuel off when it's parked.". Your vacuum tap does this automatically.

One way to check for leaks without taking the carb off is to attach a bit of clear plastic hose to the drain stub on the carburettor and run it up alongside the carb body. Put the fuel tap on prime and open the carb drain screw. If the needle valve is properly closed, the fuel level in the hose will rise to just below the float bowl flange. If it's leaking or there is a problem with the float, it will land up above the flange.

Thanks for keeping us updated, it's good to know how people get on with advice.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.
 Back to top
View user's profile Send private message You must be logged in to rate posts

pompousporcup...
World Chat Champion



Joined: 15 Apr 2015
Karma :

PostPosted: 14:42 - 14 Nov 2018    Post subject: Reply with quote

if you're going to fit a filter, get one for an early zzr600. They fit in the stock fuel line going into the carbs and won't cause fuel starvation like some of the bulky inline filters do Thumbs Up

edit:
https://www.ebay.co.uk/p/2005-Kawasaki-Zzr600-OEM-Carburetor-Fuel-Filter/1030308019

One like this. The squared edged sometimes need to be sanded down so it fits nicely in the fuel intake tube in the carbs. There is a guide on one of the gpz500 forums
ps. get it from Fowlers UK, not ebay


Last edited by pompousporcupine on 10:15 - 15 Nov 2018; edited 1 time in total
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 01:08 - 15 Nov 2018    Post subject: Reply with quote

Ok folks, so I have a new question! Everything ready to carbs out except they appear to be connected to the cooling system?! Any ideas how to disconnect it without draining the coolant and/or introducing air into the cooling system?

Cheers

P.S. cleaned the petcock up ready for the new seals. Whatever the white crystalline stuff is, it’s extremely hard!
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

pompousporcup...
World Chat Champion



Joined: 15 Apr 2015
Karma :

PostPosted: 10:04 - 15 Nov 2018    Post subject: Reply with quote

ThunderGuts wrote:
Ok folks, so I have a new question! Everything ready to carbs out except they appear to be connected to the cooling system?! Any ideas how to disconnect it without draining the coolant and/or introducing air into the cooling system?

Cheers

P.S. cleaned the petcock up ready for the new seals. Whatever the white crystalline stuff is, it’s extremely hard!


That loop is probably for the carb heater system to prevent carb icing under certain conditions.
clamp the tube going to and from the carbs or if you're quick enough, put a bolt in there to stop coolant coming out. m5 should fit iirc.

Alternatively, take this as the opportune time to change the coolant which likely needs to changed. Its not a difficult job and there are plenty of youtube vids explaining what you need to do Thumbs Up Thumbs Up
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 11:12 - 15 Nov 2018    Post subject: Reply with quote

pompousporcupine wrote:

That loop is probably for the carb heater system to prevent carb icing under certain conditions.
clamp the tube going to and from the carbs or if you're quick enough, put a bolt in there to stop coolant coming out. m5 should fit iirc.

Alternatively, take this as the opportune time to change the coolant which likely needs to changed. Its not a difficult job and there are plenty of youtube vids explaining what you need to do Thumbs Up Thumbs Up


Yeah I think I'll do this actually, took the thermostat cap off and it's a bit murky in there! Thinking of using this stuff to replace the coolant with as it seems to be suitable and won't conflict with traces of existing coolant, irrespective of whatever that coolant is

https://www.screwfix.com/p/prestone-ready-to-use-anti-freeze-1ltr-1ltr/4812H?tc=CA8&ds_kid=92700023752935861&ds_rl=1241687&ds_rl=1245250&ds_rl=1243318&ds_rl=1249484&ds_rl=1245250&gclid=EAIaIQobChMIx_mgv4TW3gIVDeh3Ch1RzgVIEAQYASABEgKjPPD_BwE&gclsrc=aw.ds
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

jaffa90
World Chat Champion



Joined: 06 Apr 2016
Karma :

PostPosted: 11:39 - 15 Nov 2018    Post subject: Reply with quote

""Prestone coolant for passenger vehicles""
This may be ok ?????
Why not this,
https://www.ebay.co.uk/itm/Two-Silkolene-MAG-COOL-long-term-anti-freeze-and-coolant-2x1-Litre-PRO-COOL/153256914913?hash=item23aed2efe1:g:5AIAAOSwnCdb6KzU:rk:8:pf:0
 Back to top
View user's profile Send private message You must be logged in to rate posts

bikenut
World Chat Champion



Joined: 21 Nov 2011
Karma :

PostPosted: 12:01 - 15 Nov 2018    Post subject: tap Reply with quote

Modern coolants dont like to be mixed, so clean/flush your system and pick a suitable coolant, then stick to it.

So tank ( including the fuel filler cap and any vents etc. ) is all clean and ready to go, along with the vac tap.

See cmsnl exploded views for your bike, there is probably a manual for it on here as well.

Clean the outside of the carbs before you "go inside" so that no outside crap joins the inside crap. Study the cmsnl exploded views of the carb and the manual, there is some delicate stuff in them.

Tackle one carb at a time, is it completely necessary to "split" the carbs into individual units ?

I dont have a sonic cleaner, but am saving for one. So the old fashioned way will have to suffice for now. Get a container ( an old gallon plastic can cleaned ) and cut the top off in such a way so that fluid poured in along with the carbs, level so the carbs are completely submerged.

You can also add stuff to displace the cleaning fluid so you don't need so much.

Make a lid form the container.

The fluid i use is petrol dosed with a full bottle of the red ex fuel cleaner, carbs left submerged for a week, agitated during the week ever day, just a lift out and then re drowned.

I strip the carbs of all strippable stuff such as jets, floats, needle valves, pistons and diaphragms and any rubber stuff, anything that the petrol and cleaner will attack, but leave them connected as one unit of 2 carbs.

Keep all carb stuff with that carb so the left float goes back into the left carb etc.. You can leave the jets etc in the cleaning fluid.

Its important to clean the outside crap off the carbs first, saves on cleaning fluid that can be saved ( twill turn black ) and filtered......

When you ready to re assemble the crabs, check all jets are clear, they have tiny holes, and all carb passages etc are all clear. A pump type oil can can prove carb passages are clear, or use a spray with the tiny tube.

Compressed air is great but verify passages and tiny holes are all clear first.

There is ample info on the net to explain how a carb works, if you understand how a plane flies and knopw some plumbing your half way there.

Honda do a good guide how the carbs for there bikes work but there are others.

You have an mot so no worries about a stuck clutch, brakes and valves etc..

enjoy.
____________________
nuts about bikes
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 13:02 - 15 Nov 2018    Post subject: Reply with quote

The Prestone stuff is supposed to mix with any coolant hence why I thought that would be a good move?
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

pompousporcup...
World Chat Champion



Joined: 15 Apr 2015
Karma :

PostPosted: 14:59 - 15 Nov 2018    Post subject: Reply with quote

https://www.eurocarparts.com/ecp/p/car-accessories/engine-oils-and-car-fluids/antifreeze-and-screenwash/blue-antifreeze/?523770501&0&cc5_865

this stuff works perfectly fine Thumbs Up
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 15:16 - 15 Nov 2018    Post subject: Reply with quote

If the Prestone stiff is OK I'll use that as a Screwfix is near my house but Eurocarparts is awkward to get to!
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts

ThunderGuts
World Chat Champion



Joined: 13 Nov 2018
Karma :

PostPosted: 23:43 - 15 Nov 2018    Post subject: Reply with quote

Update: carbs actually really clean! Unfortunately a hamfisted gorilla had been in there before so the screws were a bit chewed. Ended up using a dremel to convert the only one I couldn’t shift into a flathead then it came out nicely! Needles and their seats completely clean but one bowl had a touch of crud in it. My guess is when the tank emptied through the carbs it effectively cleaned them out.

Carbs and airbox back on. Just waiting on the petcock kit. Unfortunately I got the wrong size replacement fuel pipe but as the current stuff is showing no signs of perishing I think I’ll chance it for now.

Photos of the needle seats attached
____________________
TG.
 Back to top
View user's profile Send private message You must be logged in to rate posts
Old Thread Alert!

The last post was made 5 years, 134 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT + 1 Hour
Goto page 1, 2  Next
Page 1 of 2

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 

Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.11 Sec - Server Load: 0.21 - MySQL Queries: 17 - Page Size: 142.75 Kb