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Tappet Trouble
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Ongoing battle with the Guzzi's tappets.
The L/H exh tappet was noisy and having worked out I'd not done them for
over a year thought it might be a good idea.
The Guzzi tappets are simple screw and locknut and all were within
tolerance except the L/H exh which felt very 'gritty' when I was winding
it out. Removing it I found a few turns of the thread damaged as well as
the nut.
Imagine my surprise when I discovered the M8 1.0 threaded locknut was
over £5 from Guzzi and the tappet adjuster itself was just shy of £10.
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Try cam followers at over £25 each (I think that's inc. VAT). I
suddenly made an engineering decision that slightly pitted followers
didn't matter that much.
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Fortunately the fine threaded nut was only 20p from Namricks round the
corner (it's a 13mm spanner rather than 11mm as was but the early models
had 13mm so isn't a problem). I still had to buy a replacement adjuster.
Problem is it goes out of adjustment very quickly (2 miles) and the
threads in the rocker itself feel sloppy.
Getting a replacement rocker is going to be tricky (even secondhand,
unless JB has one?) and Friday is the only day I can work on it and I'm
on the 06.25 ferry Saturday.
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I've got one. Email with a postal addy and I'll get it down to the post
office today.
jmbyrne_AT_greenyonder.co.uk (changing the colour to blue obviously)
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Are there some splendid people here or what, eh?
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I'm thinking of Loctite - what say the panel?
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Is there room to put a second nut on, to act as a locknut?
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Drill out the duff threads, fill with chemical metal AKA JB Weld,
& tap to original thread size. YKIMS.
Let us know if it works, I've never tried it on such an application.
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I'm unhappy to do such a bodge on stressed engine internals and the price
of a fine pitch tap probably won't be too different to a new rocker.
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It might well be worth having a chat with a local engineering firm, or maybe
a decent local bike-shop, about helicoiling.
Used it myself, in fact, I bought a kit not too far back as it really does
work. Helicoils are not happy about being unscrewed and screwed up again to
many times though, but for tappet adjusters I'd have thought it just the
jobby as you never really actually back the thread right out each time you
adjust.
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I thought the issue was time, as in you not having enough to get your
hands on a new rocker before your Chimay trip, but I see elsewhere
in this thread someone has popped up with a spare rocker arm just in
the nick of time so it appears you are all sorted out.
I would also simply replace the rocker arm... unfortunately for me,
when the oil line to my ZG's cams got blocked, all the rockers (x8)
plus the cams got wiped out:
Part Number: 12016-1126
Description: ARM-ROCKER
Source: KAWASAKI
Price: $47.00
Luckily a fine fellow on the Concours forum had a spare set of cams
and rockers for beer money. There's a lot of nice folks out there.
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Having thought about it a bit more, couldn't you do the same thing
except fill the hole with brazing metal or just steel welding rod?
The adjusters and nuts for my ZG1000 are extremely hard, and are
supposed to be torqued to 18 ft-lbs, so hopefully the Namricks nut
is of similar spec to the original Guzzi one.
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18 ft/lb is pretty much the standard torque for an M8 nut.
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The ones I was referring to are 7mm, so not too much different.
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Tappet, tappet, tappet, tappet torque
Torque about things you can't undo
<\spm>
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I read your posts and sometimes have to really wonder what's occurring
inside your head.
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*You* wonder?
Try being on this side of it.
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If you're eventually going to get a new rocker, use Loc-Tite's "Stud-loc"
and it'll never move again. You WILL have to buy a new rocker and adjuster
though or hit the parts with a gas axe to break the bond.
Nothing ELSE but Stud-loc will go even halfway to seeing it work for a
decent time period.
Thread-loc CERTAINLY won't, nor will Loc-tite 240 or 242. IIRC the number is
270 (ish) for Stud-loc
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