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Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 8:11 am
Author: JohnC
My bikes smokes slightly on start up and it seems it's probably hardened valve stem seals, APE ones on my bike and I think someone said these harden with lack of use.

I was given a bottle of this by my father-in-law, said it worked on an old MG he was working on for a friend.

https://www.amazon.co.uk/gp/product/B00 ... UTF8&psc=1

Does anyone have any experience of these actually helping?

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 8:16 am
Author: Robw
Having had problems with vave guide oil seals myself and discussing the problem with Chris at Grumpy 1260, Ape seals worked perfectly well with Ape valve guides, but not with standard ones. So I always fit genuine ones now and not had any problems.
Rob

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 11:51 am
Author: Garry.L
JohnC wrote:My bikes smokes slightly on start up and it seems it's probably hardened valve stem seals, APE ones on my bike and I think someone said these harden with lack of use.

I was given a bottle of this by my father-in-law, said it worked on an old MG he was working on for a friend.

https://www.amazon.co.uk/gp/product/B00 ... UTF8&psc=1

Does anyone have any experience of these actually helping?


S'pose for a Tenner it's worth a go, but just smacks of Snake Oil to me....

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 12:40 pm
Author: jonhunt
Not sure I see how this works. If a seal is worn what does do? Increase viscosity? Fill the gap?(risk of clogging the oil galleries). Make the seal swell? (Then it will do this to all the seals)

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 1:08 pm
Author: Charlie
Sounds like another snake oil to me :wink:

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 1:22 pm
Author: ZedHead
APE stem seals are made of FKM (Viton) which has a shelf life of 20 years compared to other materials with a shelf life of 5 - 10 years.

It is possible that the valve stems have lost surface oil if stood for a period resulting in seal damage on start up. Replacement seals is your only option I am afraid.

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 5:23 pm
Author: baz
it will work ....for how long I wouldn't like to say.
when I was a plant fitter we used something similar in the hydraulic system, when a machine was say seven years old and ready to trade in we used to add a gallon of that stuff into the hydraulic tank, run it for a few hours and 80% of the leaks from rams, valve blocks etc would dry up, even leaks on rams with scours in them would slow down. theres a chemical in it that causes the rubber to go supple and swell slightly, never kept the machine for more than a couple of months after that though.

Re: Valve stem oil seals and valve seal conditioners

Posted: Mon Jul 22, 2019 8:03 pm
Author: jonhunt
I worked in the seal industry in the dim and distant. Valve stem seals are controlled leakage devices they need to let some oil through to keep working

Re: Valve stem oil seals and valve seal conditioners

Posted: Tue Jul 23, 2019 3:29 pm
Author: JohnC
So all, is a bit of smoke on start-up acceptable? And how do I pitch this on a potential sale? It's not using / burning any oil, and it goes away the minute you pull away when warm, and pulls like a train (Wiseco 1075 & VM 29 Smoothbores).

I'm probably going to sell the bike on Ebay, or I might put it in the forum first for a ' how much is it worth' and hopefully sell it to a Zed enthusiast who knows this an easy fix and not much of an issue. I'd happily get the seals done but there is no-one in Scotland I'd trust, and I'd need to get the bike transported down to Debben or a few of the other Zed specialist to trust a good job. Plus as it's not burning any oil it seems pointless to strip the bike down just for the valve seals. Compression at the last time I checked was 140 - 145 on all cylinders. The bike can hoist the front wheel off the throttle so it's not lacking in power :D

I'd keep the old bugger but just a bit heavy for me now as I'm getting on a bit and now have joint issues, or I wouldn't have this conundrum as I love the big beastie :(

Re: Valve stem oil seals and valve seal conditioners

Posted: Tue Jul 23, 2019 3:36 pm
Author: ZedHead
JohnC wrote:So all, is a bit of smoke on start-up acceptable? And how do I pitch this on a potential sale? It's not using / burning any oil, and it goes away the minute you pull away when warm, and pulls like a train (Wiseco 1075 & VM 29 Smoothbores).

I'm probably going to sell the bike on Ebay, or I might put it in the forum first for a ' how much is it worth' and hopefully sell it to a Zed enthusiast who knows this an easy fix and not much of an issue. I'd happily get the seals done but there is no-one in Scotland I'd trust, and I'd need to get the bike transported down to Debben or a few of the other Zed specialist to trust a good job. Plus as it's not burning any oil it seems pointless to strip the bike down just for the valve seals. Compression at the last time I checked was 140 - 145 on all cylinders. The bike can hoist the front wheel off the throttle so it's not lacking in power :D

I'd keep the old bugger but just a bit heavy for me now as I'm getting on a bit and now have joint issues, or I wouldn't have this conundrum as I love the big beastie :(


Price it fairly! These are old bike so a little smoke on start up should not be a huge surprise to most.

Re: Valve stem oil seals and valve seal conditioners

Posted: Tue Jul 23, 2019 4:05 pm
Author: Julian_Boolean
ZedHead wrote:Price it fairly! These are old bike so a little smoke on start up should not be a huge surprise to most.


As above, personally I'd have no problem buying an old bike that smokes a little on start up, it certainly wouldn't bother me enough to take the head off and do something about it.

Re: Valve stem oil seals and valve seal conditioners

Posted: Tue Jul 23, 2019 4:33 pm
Author: JohnC
Hi ZedHead, thanks for the info over the past few emails I've posted. Any ideas what would be a fair price? I'd rather sell to a good home than make a profit.

Owned by myself since 1992, hundreds of receipts kept over the years.

Engine is 1075 Wiseco, HD valve springs, APE valve spring retainers, crank rebuild by Debben with new rods / bearings, etc, other head work done valves reground new seats etc (about 4000 / 5000 miles since the rebuild), APE HD crank case / cylinder studs, main bearing studs etc, roller clutch push rod conversion, HD clutch springs, VM 29mm Smoothbores (£300 + spent on new internal from Allens Performance), brand new genuine K&N filters, Dyna Ignition, coils, Taylor leads, billet manual cam chain tensioner, HD Tsubaki race cam chain, Billet cam end plugs, Stainless one off exhaust (by the same guy that used to make Jim Moodies echausts - SWONA), Arkront rims, high flow Pingel fuel tap (think this is a pattern one tbo), Deep braced JMC swinging arm (could be doing with re-powder coating if your really fussy but is OK atm), brand new 520 (?) Debben Chain / Sprocket Conversion kit, Koni shocks, progressive front springs, Specials (Glasgow) Spondon 13 inch fully floating discs and Nissin 4 pot calipers, brand new HEL brake lines, brand new EBC fully floating rear disc (not in photos as still to be fitted), new pads all round, brand new (pattern) switch gear, brand new radial ClassicAttack tyres front and rear just fitted so not in photos, brand new front mudguard (ZPower) still to be fitted, most other chrome is OEM and in good condition, Genuine mint GIULIARI/ 2/4 seat and standard OEM seat in great condition. brand new chrome mirrors (not in photos still to be fitted), brand new Motobatt gel battery just fitted. Brand new = meaning just fitted or next to zero miles.

Cheers and thanks for your help.

John

Re: Valve stem oil seals and valve seal conditioners

Posted: Wed Jul 24, 2019 11:56 am
Author: deka
thats lovely and taste full mods, a little smoke on startup would not bother me neither good luck with the sale

Re: Valve stem oil seals and valve seal conditioners

Posted: Wed Jul 24, 2019 1:57 pm
Author: Julian_Boolean
I've no idea what it's worth, but it is very nice.

Re: Valve stem oil seals and valve seal conditioners

Posted: Wed Jul 24, 2019 2:57 pm
Author: ZedHead
I have given up trying to figure out what bikes are worth these days.. For Mint original bikes, asking prices seem to be:-

73 Z1 Upto £30k
74 Z1A/B Upto £20k
76 Z900 A4 Upto £14k
77 Z1000 A1 Upto £10k

Of course these are asking prices it does not mean this is what they go for. Also specials are not usually as desirable to a wider audience.

My guess, and it is no more than that, on a nice bike like yours. £7-8k.

Then again that will just about get you a mobility scooter from Frank these days :roll: