interest in getting cheap(er) choke plunger springs?

[icenian]

in the unlikely event that any AT owner hasn't had their choke plunger sieze up (bad running at low revs, poor idle, poor fuel economy), have a quick look at this thread:
http://www.xrv.org.uk/phpBB2/viewtopic.php?t=4693

The replacement parts from Honda cost about 46 pounds per choke. But one possible problem is that the spring has corroded and is too weak to push the plunger back in. To get the OE spring costs 46 pounds as you have to buy the whole kit of parts!

Which is why my choke is now bodged with a biro spring...

I could investigate getting suitable springs from another supplier. I'm thinking it would be good to get a set of 6 springs - 2 springs as close as possible to the OE item; 2 springs about 20-25% stiffer; and 2 springs about 40-50% stiffer? The reasoning being that the OE spring is a bit feeble so a stronger one may help, and having a heavy action at the choke lever isn't exactly a big problem (though you might have to hold it on if the spring is really stiff).

Unit cost is going to fall dramatically if there's several people interested, as the minimum order is about 30 pounds. I'm happy to go with a concensus if others think my idea of 6 springs per person is daft, but buying 2 or 6 springs each isn't going to affect cost much, so if I organise it I'd want everyone to agree what we buy and everyone gets the same stuff, just to keep it simple.

If you're interested, please use the poll to vote yes, to save me counting responses in this thread!

[ali]

I hope it never happens, but I'm happy to go in on a job lot and they can hang around my garage looking useful....

Thanks,

Ali

[chronyx]

Happy to pay a tenner and never use the choke so stiffness doesn't fuss me either.

[DaveS]

The site can fund the minimum order if you want or stand guarantee if you don't get your minimum.
I'll happily take any excess and sell them on the site shop.

[icenian]

The site can fund the minimum order if you want or stand guarantee if you don't get your minimum.
I'll happily take any excess and sell them on the site shop.

Thanks Dave.

The minimum order works out at 26.44, so I think that will provide more springs than we need. If nobody minds, we could pass these on to you for the shop, proceeds going to support the site.

Incidentally, to get a match I need to measure the wire diameter, outside diameter of the spring, free length and compression rate. I have one spring purchased at vast expense from Honda to work from (using an old spring isn't going to work; we know they go soft, which is part of the problem).

Outside diameter and free length are easy. Wire diameter is hard (I don't have a micrometer(?)) but I can probably figure out which is the nearest thing that Springmaster stock - it doesn't need to be a perfect match.

The hardest thing is going to be spring rate. In principle it's easy - how much force is needed to compress the spring 1mm. In practice it's not such an easy thing to measure at home. I can compress it by 10mm by squashing it on the kitchen scales, but they're not going to be very accurate for such a small load!

[Simon]

i would take some just to have for the future

[Dilbert]

Spring Rate is a function of the spring dimensions and material, but if you can accurately get the dimensions the material is unlikely to be that big a factor, don't forget the pitch and total number of coils when specifying.

If you can't get the wire dia measured accurately pm me and send me a spare spring and I'll get it miked up

To measure the spring rate, put the spring inside a clear tube and drop in lead shot of a known weight (weigh a bagfull and divide by number of pellets) and measure the difference, vernier height gauge is best (or the depth gauge fitted on vernier calipers.

[icenian]

To measure the spring rate, put the spring inside a clear tube and drop in lead shot of a known weight (weigh a bagfull and divide by number of pellets) and measure the difference, vernier height gauge is best (or the depth gauge fitted on vernier calipers.

Excellent method!

Now I need some shot... have to eat a lot of pheasant
(Don't tell me there's another way to get lead shot. I don't want to know.)

[xrv_jim]

If you can get them for a around a tenner, count me in too.

[Grader]

Just voted, I'd be very interested to have a set as spares for the day when my choke stops working.

I read in previous posts that the plastic fitting that holds in the spring often breaks on disassembly, does anyone have a picture of this? Does it have to be plastic or would a metal replacement work? If so maybe we could measure one and make a design to facilitate replacements being made (my dad is pretty handy with a lathe for example). Just a thought...