Fitting valve stem oil seal. Very tight fit. Any tips?

[stinkwheel]

It's on my Enfield 350 bullet.

The valve stem oil seals are a very tight fit on the end of the valve guide. I'm used to just pushing them on with my thumb but no way with these ones.

I've already trashed one set trying to tap them on using a deep socket as a driver.

Any hints and tips appreciated.
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“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.

[temeluchus]

Try Davel Angel at F2 motorcycles. He used to be an enfield dealer and is always helpful.
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Some shite cruiser. Now with guns and FREEDOM!

[stinkwheel]

It has been suggested from a pretty expert source that I just leave them off on account of having fitted new valve guides.

I wonder if anyone has an oppinion on this?

If it's burning oil, I suppose I could always retro-fit them once it's all assembled by stuffing a bit of rope down the sparkplug hole to hold the valves up while I pop the springs off.

I'll mull this over a bit.
____________________
“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.

[Charlie]

Possibly try using this, not exactly sure it is what you need but making it cold will reduce it sizes and might make it fit...

Think that was what my Dad used recently on something that he was struggling to undo.
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Past: Honda x8rs, Honda City fly, Honda Hornet 250, Honda VFR750, Yamaha xt600e.
Current: Honda CBR929RR & Yamaha XT660Z Tenere

[Bru]

I have read that some valve stem seals come with a sleeve to aid their fitment. The sleeve fits over the valve stem end, and the seal slides over the sleeve, avoiding the sharp edges of the collet undercut and consequent damage to the seal lip. I have not found any separate tool items on the Net, so it may be seal-specific.

[tatters]

resently fitted new valve guides on a BSA B44 which did,nt have any seals, had no oil burning issues afterwards.
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[virus]

Id try boiling the seals to warm them up and make the rubber a bit more supple, along with the slightest slip of light oil on the stem to help it slide.


If that doesnt work then the retrofitting at a later date IF it burns oil idea seems like a good one.



Cheers
John
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own: 81 xs1100g...
owned: 85 rat CG (sold), 91 GS500e (stolen), 84 gsx400f (scrapped), 81 z250 (siezed, siezed, scrapped), 83 cb250rs (sold), 84 gpz750r ratfighter (killed) 84gpz400 (sold), '80 cb650 ratfighter (wrote off) 95gsx6/12f ratfighter (killed) 91 xj900 (sold)
stinkwheel Well I just had my hands up a pigs fanny. Which makes your concerns pale into insignificance.

[Bru]

Boiling the seals.. great idea. Really - I have used hot water to fit hose onto barbed spigots, so why not with seals. Can't be any hotter than the operating temperature of the engine in that area.

[stinkwheel]

They are nitrile rubber cups with a metal band round the body of the seal and a spring round the valve stem.

On looking into things further. They started fitting oil seals to these bikes from the factory in 2005. So for the first 53 years of production, they had no valve stem oil seals.

The valves and valve guides are identical to the 1952 bike (you could put my ones in an original, Reddich built bullet). I suspect they have fitted stem seals to make up for deficiencies in the Indian made valve guides. I have fitted a set of aftermarket, British made ones.

I think I'm just going to leave them off. It's not a big job to strip the head to fit them later if I need to. That way I can get the bike built tomorrow and start running it in.
____________________
“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.

[Robby]

With some heat, oil and patience you may be able to try stretching the bottom of the seal on something rounded - off the top of my head, one of those pens with 16 different colours in it that girls had at school would be the right girth.

On second thoughts, those pens were probably just about the right fit on a 14 year old girl. I used to borrow them sometimes. Win.

That said, if the seals don't fit then I assume that either they're the wrong size, or the new guides are a bit thicker or have less taper where the seals go on.


It's an Enfield. It might burn a small amount of oil without seals, but not as much as will leak. It certainly won't be running dry between your 1000 mile oil changes. Just think of it lubricating your valve stems. If it smells like burning oil, chuck some 2-stroke in the tank so mask the smell and make it nice.

[Ichy]

I seem to remember that Harleys never used to have seals. I think the idea of fitting seals was to reduce the risk of the valve stems coking up.

[temeluchus]