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Re: MX5 fuel filler valve not working very well

PostPosted: Wed Apr 08, 2020 2:45 pm
by The Veg
I had a threaded bung brazed into the neck by my local radiator-repair shop, and then they ground-down most of what protruded on the outside so that the neck could still slip through the grommet. I think they charged me a whopping $10 for the job.

Re: MX5 fuel filler valve not working very well

PostPosted: Wed Apr 08, 2020 4:08 pm
by JonB
We don't really have local radiator repair shops round here, sadly; and I have no lathe equipped friends!

Which explains why I've not tried to implement the mod yet.

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 8:29 am
by alan.barker
What's the biggest size for a "Rivnut" :?:
Alan

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 8:40 am
by Mudmouse
Alan, I see where you are going with a Rivnut however the shoulder on a Rivnut would be too large to get the body sealing grommet over so would not work. The outside of the filler tube must be flush. When I soldered the brass reducer to the inside of the filler tube it was very straightforward. The only issue is having a reasonably sized soldering iron, carefully cleaning the inside of the tube, good flux and preventing the solder running too far (hence use of solvent Tippex).

Steve

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 9:21 am
by alan.barker
Steve,
i like the tip about the Tippex Solvent. You're right of course about no projection on O/Dia.
It's already a tight fit in the Grommet.
Alan

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 10:57 am
by john.p.clegg
If you've a blowlamp?

Silver soldered mine...

John ;-)

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 11:23 am
by Mudmouse
John, I almost did the same but when I saw how close the filler cap fitting (which is soft soldered onto the filler pipe) was to the brass reducer that I fitted I decided to soft solder it to the tube. Silver solder flow temp is between 650 to 780 deg C whereas lead soft solder is 180 deg C

Did you put a heat sink on the cap end to reduce this risk?

Steve

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 12:04 pm
by gav
Excuse my ignorance but where does the other end of the vent go to?
Thanks
Gavin

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 12:25 pm
by Mudmouse
In my case the vent from the filler goes to the nearest tank vent fitting and the other vent goes via a tank pressure limit valve to the normal +2 vent which comes out by he rear wheel after going via the roof.

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 1:33 pm
by john.p.clegg
Mudmouse wrote:John, I almost did the same but when I saw how close the filler cap fitting (which is soft soldered onto the filler pipe) was to the brass reducer that I fitted I decided to soft solder it to the tube. Silver solder flow temp is between 650 to 780 deg C whereas lead soft solder is 180 deg C

Did you put a heat sink on the cap end to reduce this risk?

Steve


Not that I remember,but I may have it stood on my Steel Flatplate while doing it..

John ;-)

viewtopic.php?f=51&t=33994

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 2:51 pm
by alanr
Gavin,
You need to have a read of the Club Lotus Breather Mod.
Elan +2 Petrol Tank Mod.pdf
(942.32 KiB) Downloaded 204 times

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 7:33 pm
by gav
Thanks Alan

That’s a really useful article which clearly explains the issue and solution.

Much appreciated

All the best
Gavin

Re: MX5 fuel filler valve not working very well

PostPosted: Thu Apr 09, 2020 7:57 pm
by Matt Elan
Hi Jon
I’m fully lathe equipped if you need a spot of turning once we are out of lockdown
Mat

Re: MX5 fuel filler valve not working very well

PostPosted: Fri Apr 10, 2020 7:53 am
by JonB
Oooh you lucky fellow. Mind you, if I had a lathe I wouldn't know what to do with it. I'd need training.

Thanks, I'll let you know... come to think of it, a nice drive out to your neck of the woods might be very pleasant once this is all over.

JonB