GTS OWNERS CLUB

smudger

Take a look at the picture below...

this is what my PM looks like after I changed to stainless steel studs and brass nuts. As you can see the clearance between the nut and pipe will not allow any socket to fit over it. This is because the Lammy M7 brass nuts used fit an 11mm socket while the standard M7 nuts fit a 10mm socket which works....

I know others have done this but mine is a brand new PM pipe and maybe the exhaust manifold is wider on the newer pipes??? Question

To say it was a nightmare to tighten them with a spanner is an understatement Exclamation

Any engineers out there have any ideas how to work this??? The only solution I can see is to use non brass M7 nuts that fit a 10mm socket and run the risk of them heat seizing to the pins like the originals did.

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buddyphil · Posted: Tue Sep 23, 2008 9:34 pm Post subject:

i turned a 11mm socket down in a lathe
works a treat

jetex · Posted: Tue Sep 23, 2008 9:45 pm Post subject:

Looks to me Smudge, that you've got the nuts on upside down. The rounded part should sit on the flange allowing the hexagonal to sit off a bit more. You may then be able to get a socket on ? Whatever you do, don't go back to steel nuts, for the reasons you state.

Maver · Posted: Tue Sep 23, 2008 9:50 pm Post subject:

jetex · Posted: Tue Sep 23, 2008 10:04 pm Post subject:

Depends on how sloppy a fit the stud is in the manifold hole, and how long the stud is. I would go for a flat and spring washer, but if the brass nut has a boss on it and the stud is a pretty close fit, then you would get away without using any washers.

MikeHolland · Posted: Tue Sep 23, 2008 11:18 pm Post subject:

I also fitted standard nuts and turned down a socket. Works a treat!

Mike
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Vespa GTS250 Vintage Red

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Why not just use the genuine downpipe nuts from piaggio as they are brass now and fit a treat Question

smudger · Posted: Wed Sep 24, 2008 8:53 am Post subject:

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Yes they are M7 and use a 10mm socket... brass locking nuts.

smudger · Posted: Wed Sep 24, 2008 9:19 am Post subject:

GAVSKIN · Posted: Wed Sep 24, 2008 10:48 am Post subject:

what do i have on mine then CT? i think i need to check my nuts for tightness after wooly Laughing

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NORWICH BROADSMEN S.C

martin68 · Posted: Wed Sep 24, 2008 4:27 pm Post subject:

I use a long allen key to tighten my exhaust nuts by using one that fits into the drive of the socket. The thin allen key allows you to get between the engine mounting cradle and tighten the nuts free from obstruction using a spanner to turn it. It works a treat and cuts down on the time the job takes and fustration level. Wink

rainham boy · Posted: Wed Sep 24, 2008 4:43 pm Post subject:

i used a cut down spanner to do mine Shocked

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Darkside, Norwich Broadsmen SC

Browney · Posted: Wed Sep 24, 2008 5:46 pm Post subject:

rainham boy · Posted: Wed Sep 24, 2008 6:21 pm Post subject: