Author Topic: Tappet covers  (Read 6418 times)

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Offline trakadaka

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Tappet covers
« on: 02 May 2008 at 07:59 »
I've just received tappet covers from London. I realise we need to drill a hole in them, but how do we actually attach them to the bike? There doesn't seem to be anything to screw a bolt into. Do I need a clip etc?

Offline roy

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Re: Tappet covers
« Reply #1 on: 02 May 2008 at 08:22 »
Trace, if you look at the first photo on my previous posting, you can see the eye bolt fixing between the valve springs, it has thread on one end , as you said , drill a hole and slide cover on, fixing by use of a nut. Roy.







Edit 02/05/2008: Referred photo linked. A.
« Last Edit: 02 May 2008 at 12:23 by alwyn »

Offline trakadaka

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Re: Tappet covers
« Reply #2 on: 02 May 2008 at 08:29 »
A-ha, very good. Thanks.

Offline trakadaka

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Re: Tappet covers
« Reply #3 on: 06 May 2008 at 10:50 »
A-ha, very good. Thanks.
The bolt between our valves is much shorter than the one shown in your photo. Do I...
unwind the bolt to increase the length and put the eye bolt onto it, or replace the bolt with a longer one?
Probably a silly question, but I don't want to touch the bolt without knowing what it is connected to. Better to be safe than sorry.

Trace

Offline Doug

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Re: Tappet covers
« Reply #4 on: 07 May 2008 at 02:54 »
Trace,

It should be a stud between the valves; sounds like yours has been replaced with a bolt? The first nut on the stud secures the cylinder to the crankcase. The second clamps the tappet cover eye bolt to the stud. You can see the two nuts straddling the eye bolt in the picture Roy mentioned.

Do not back out the stud to make it longer, it needs all the purchase into the crankcase threads that it can get! You may need to find and fit longer studs to suit. I am pretty sure the same stud was used right through to the 1936 250/350cc models.

-Doug

Offline trakadaka

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Re: Tappet covers
« Reply #5 on: 07 May 2008 at 09:32 »
Trace,
It should be a stud between the valves; sounds like yours has been replaced with a bolt?.....-Doug

Thanks Doug. I'll replace the bolt with a longer stud. Are there any special instructions when removing the bolt, ie nothing will fall off inside?

Trace.

Edit 07/05/2008: Quote tags adjusted - please avoid quoting whole messages - refer post in 'Guidelines' board re 'Forum Etiquette' here. 
Thanks, Alwyn,
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« Last Edit: 07 May 2008 at 12:20 by alwyn »

Offline Doug

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Re: Tappet covers
« Reply #6 on: 07 May 2008 at 12:33 »
Trace,

No, there should be no problem about anything inside coming loose. The crankcase is tapped solely to take the stud for the cylinder. The threads do not project into the timing chest cavity.

-Doug