Fitting kickstart oil seal (1965 B40F)

[Phil C]

I know I'm forever asking questions, but I'm learning all the time, so thanks for your patience. Regarding my kickstart seal, you'd think, wouldn't you, that a new seal would press in to it's hole pretty easily with some oil and firm thumb pressure? Mine doesn't want to. I damaged one trying to tap it in using a socket and a hammer (not hitting hell out of it, obviously) - it got a bit pinched at one part of the circumference, so I took it out and am now trying to fit another, but it's very tight and doesn't want to even start to go in around the whole circumference. At present the casing is on the bench. Is it better to put the casing on the bike first so that the shaft centralises the seal, before trying to push it home? Is there a secret to this?   Phil

[Phil C]

Okay it in. Gentle tapping with nylon hammer.

[Phil C]

I thought that was going to happen. With the new oil seal in place in the outer casing, I tried to carefully trial fit the casing (with the points wedged open to avoid snagging on their cam.) It didn't want to push on, the oil seal being a fairly tight fit on the kickstart shaft. So I tapped it on very gently with a rubber mallet, which worked fine except the actual sealing part of the seal turned inside out, so it's sticking outwards. How can I avoid that happening?   It was oiled. Phil

[Phil C]

Here's a photo of it. I guess that's not what's meant to happen.   Phil

[Phil C]

Oh dear, it's not going well. I see the spring has come loose now, so I'll have to remove the seal and fit another new one. That will be the third. Before I do that, could anyone advise on the problem of the seal turning inside-out please? Phil

[Phil C]

Just a bit more info on my little saga: the kickstart shaft was very tight in its bush, until it was fully in, when it felt a nice fit.  Putting a micrometer across the shaft in various places, I came across a high spot of a few thou near the flat. So I've stoned that down and it's now a nice fit. But as I'm down to my last oil seal I'm delaying fitting it until - hopefully - I get advice here on the forum about how to prevent the inside-out thing. Thanks in advance for any help.   Phil

[Willie Dee]

The recess for the cotter has caught it and pulled the lip. Wrap some tape round that, grease it and slide the seal over it. I would think there would be a sleeve to fit over the shaft to slide the seal up.

[Phil C]

I know the edges of the flat catching on the seal is quite common, but in this case the seal was turning over as soon as the end of the shaft pushed through, so before it reaches the flat. But I have just found that by taking the shaft off the bike, and fitting it through the seal on the bench, the seal turned over but then I rotated the shaft a couple of times and the seal appeared to find it's way back into the correct position.  So now I'll fit the casing complete with shaft. Fingers crossed. Phil

[Phil C]

Ah, just remembered: kickstart spring.

[Phil C]

For goodness sake, why is this so difficult? Realising that fitting the shaft through the seal on the bench (rather than on the bike) was no good because I then wouldn't be able to fit the kickstart spring, I put the shaft back on the bike. Offered the outer casing up and the seal slid over the shaft okay. Encouraged by that, I took the casing off again and went ahead and put hylomar blue on both surfaces and tried to fit the casing, screws at the ready. The seal went inside out again and the seal spring broke. So, embarrassingly, that's three new seals I've gone through, I've got none left, it's a public holiday so I can't get any more yet, and I've still not got the outer casing in place. Worst of all, I still don't know how to sort this, or how many seals I'm going to get through before I finish. Is it usually this difficult?   Phil 

[DAVE BRADY]

Hi Phil,

You seem to be having a very frustrating time.  One thing that might be worth trying when you get some more seals is to fit the case complete with kick start spring etc. and then fit the seal over the kick start shaft and tap it in to its recess.  WD40 should be slippy enough to help ease it on.
If you have a box spanner or socket that will fit over the kick start shaft use that as a drift but put large washer on first to get a more even impact.  It may be worth trying to push it in a bit before using any impact.

Dave.   

[Phil C]

Yes, thanks Dave, I'll try that. Sorry I was a bit fed up earlier. Already feeling more positive, confident even. I'll be ordering more seals on Tuesday (a couple of dozen should do it.) And there's more lockdown easing soon!  Phil

[Phil C]

Received three more oil seals in the post today (I know, ridiculous.) Put the outer casing back on the bike. Tried to fit a new seal, using a socket, a washer and a nylon hammer. Couldn't get it started with finger pressure alone, so had to tap (using socket and washer.) First one pinched at one point in circumference, so removed. Second one pinched a bit also, so I pushed the pinched bit in with the rounded end of  a six- inch rule and it now looks okay, I'd say (no photos, sorry.) But is it, I wonder. What do you reckon? I guess the proof of the pudding... ?    Phil

[Pete A10]

This might sound daft Phil but I assume you have plenty of grease on the shaft before you push the oil seal on? If not then the lip will grip and fold over. If your relying on thin oil the design of the oil seal will strip this off as it goes on. It helps to have the seal well greased for long term wear as well.

[Phil C]

I used oil. The seal is okay until I try to push it into the housing, where it's a tight fit. Too tight to push in stall by thumb pressure. It's as though the hole is a touch too small.
Any comments anyone please regarding my previous post in which I explained it had pinched slightly at one part of the circumference and I pushed it back in with the rounded end of a six- inch rule. Can't send a photo at the moment as I don't have Paint on my mobile.   Phil