Author Topic: 250E - Won't run properly with in-line fuel filters  (Read 377 times)

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Offline Tailchaser

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250E - Won't run properly with in-line fuel filters
« on: April 07, 2021, 07:40:38 PM »
Hi all,

Bit of an odd one and have had a search so I think I know the answer (remove them!) but thought I ask:

As there had been some flash rusting in the tank after a re-spray I thought I put a couple of in-line filters on to catch any junk before it got into the carbs. Well, the bike started 3rd kick after it's winter hibernation, knocked it off choke and with a couple of seconds it died. Did the usual checks and scratching of head and tried again - exactly the same - and repeat.

Removed the filters and bingo - as good as gold - ticks over smoothy, picks up really cleanly!

Is it just the actual flow on these bikes is quite low and the slightest extra bit of 'resistance' is enough to cause starvation?

Hoping that in in-tank filter is fine enough but doesn't get blocked.

Cheers,

Jeff
RD250E

Online Gr8uncleal

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #1 on: April 07, 2021, 07:47:10 PM »
I think that another member (tonytwostroke?) had a similar issue with his RD200.
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Online tony2stroke

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #2 on: April 07, 2021, 08:30:28 PM »
I think that another member (tonytwostroke?) had a similar issue with his RD200.

Yes I did, well remembered, I think 5port had the same issue and a couple of others too, don't know why, but I could start bike start to ride and suddenly it would die, there was a air lock forming in the filter, you could see fuel in it, but it would not go down to carbs, I put it down to vibration causing it, removed them and fine again, can only wonder why it only happens to some and others work OK, strange 1 this.

Offline kawazonkey

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #3 on: April 07, 2021, 09:20:38 PM »
Are they fitted the right way round?

Online 5port

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #4 on: April 07, 2021, 09:33:16 PM »
Yes, I have had problems with small inline fuel filters.  I feel that the relatively low head of pressure can be a problem, it is possible to get air locks and restrictions.  OTOH, some people find them to work fine.  ???
Cheers

5port
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Offline Bluehaze

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #5 on: April 08, 2021, 12:51:34 AM »
Apart from being not pretty and unnecessary, small inline filters can cause problems.
They can look clear but still be clogged.
If you must have them, replace yearly.

Offline Ozhammer

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #6 on: April 08, 2021, 02:27:17 AM »
I use inline filters on my bikes without any issues at all but as said, I do replace them annually.

HTH
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Offline Tailchaser

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #7 on: April 08, 2021, 08:35:07 AM »
Thanks all for the comments, etc - think I'll consign them to the 'parts bin' and run it sans filters as Yamaha intended.

Cheers,

Jeff
RD250E

Offline ajh

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #8 on: April 08, 2021, 04:07:36 PM »
I cant see theyre needed if the petcock filter is intact. (Ive skillfully moved the conversation to the petcock filter so I can ask a question :)  )

My petcock filter is very loose in the petcock and I'll need ot glue it in somehow. Given this will be immersed in petrol 100% of the time, anyone got any tried and tested petrol proof glue they can recommend? Or a clever idea to make it tight in the petcock?

Cheers all!
in Chiswick, West London

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Online tony2stroke

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #9 on: April 08, 2021, 06:12:13 PM »
I cant see theyre needed if the petcock filter is intact. (Ive skillfully moved the conversation to the petcock filter so I can ask a question :)  )

My petcock filter is very loose in the petcock and I'll need ot glue it in somehow. Given this will be immersed in petrol 100% of the time, anyone got any tried and tested petrol proof glue they can recommend? Or a clever idea to make it tight in the petcock?

Cheers all!

What I did was to warm up the 2 little ends that go into tap and opened the ends up a little with something that fitted, I think it was an old bit of aerial wiggled around to stretch the plastic, 1st off I over did it, but then I just warmed it back up and pushed into the tap, worked a treat.

Offline martin1957

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #10 on: April 08, 2021, 06:45:01 PM »
I have had loads of problems with in line filters. I think its airlocks etc. Same on a single cylinder 4T petrol motor. If if flick them around a bit while I tickle the carb, you can see the petrol flow. Once its running, the wobbling about keeps it going.

As said, good filters in the fuel tank and pet cock should do the job if kept clean......

Glad im not the only one that has found this is a problem.....
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Offline ajh

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #11 on: April 08, 2021, 06:57:01 PM »
I cant see theyre needed if the petcock filter is intact. (Ive skillfully moved the conversation to the petcock filter so I can ask a question :)  )

My petcock filter is very loose in the petcock and I'll need ot glue it in somehow. Given this will be immersed in petrol 100% of the time, anyone got any tried and tested petrol proof glue they can recommend? Or a clever idea to make it tight in the petcock?

Cheers all!

What I did was to warm up the 2 little ends that go into tap and opened the ends up a little with something that fitted, I think it was an old bit of aerial wiggled around to stretch the plastic, 1st off I over did it, but then I just warmed it back up and pushed into the tap, worked a treat.

Hey Tony youre on a roll with petcocks! :)
I was thinking about heating it and trying to add some material but your idea sounds much easier. 
And on the previous chat about the leaky tap, as you said I cleaned up the little plastic cone with some wire wool and greased it all up and so far no leak! Have to wait for the petrol to wash through the grease a bit before Im convinced
Thanks for your help!
in Chiswick, West London

77 RD250d, 80 DT175mx, 81 4L0 350LC

Offline Tailchaser

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #12 on: April 08, 2021, 07:14:58 PM »
I wonder if the 3D printer folks would be able to reproduce those plastic/nylon cones as I've got a couple of taps with 'iffy' cones in them?
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Offline ajh

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #13 on: April 08, 2021, 08:36:35 PM »
I wonder if the 3D printer folks would be able to reproduce those plastic/nylon cones as I've got a couple of taps with 'iffy' cones in them?

I did wonder that too, dont know if itll be worth their while but bet theres some pent up demand. I know theres Alan Kelly on the LC forum and there was someone else on this one
« Last Edit: April 08, 2021, 08:39:25 PM by ajh »
in Chiswick, West London

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Offline Phil S

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Re: 250E - Won't run properly with in-line fuel filters
« Reply #14 on: April 08, 2021, 09:58:10 PM »
I will clean my tank with Deox C flush it afterwards and then put additive in over the winter, heard mixed results on use of fuel filters and I avoid them.