This can't be right!

[Monk]

Fiddlin' with the Sporty today I noticed something... The flange that holds the rear exhaust pipe/coupling at the rear head is loose. Really loose. Really, really loose!!
Like, one nut is missing, even.

It moves easily in and out on the studs, but I need to get the correct size nut to tighten it down.

Anybody know what size that nut should be? It appears to be a grade 8, but I don't know if it's some oddball thread..?

BTW - haven't been able to find it mentioned in the manual anyplace.
Help.

[Dave63]

If it's the nuts that go onto the studs, that hold the collar and subsequent pipe to the head, they're 5/16" x 24 thread. They should also be flanged nuts.

You can get away with a lock washer and a regular nut, in a pinch.

[blackwell33]

last time I put my exhaust back on, I double nutted it.. might wanna grab a few extras to give it that added extra snugness. It makes me feel better anyways..

[Rockerbox1]

Originally Posted by blackwell33

last time I put my exhaust back on, I double nutted it.. might wanna grab a few extras to give it that added extra snugness. It makes me feel better anyways..

last time I double nutted something....she got pregnant

[MrMarty51]

Originally Posted by Rockerbox1

last time I double nutted something....she got pregnant

[Monk]

Kewl... get that taken care of tomorrow! Now then... how serious is it that I've been runnin' it with no back pressure on that rear cylinder for God knows how long..?

Thanx guys! You da man!

[SonnyD]

Ah, I bet you weren't loosing much pressure or you would
have noticed something wasn't right. It probably just
recently happened. I'd think if it had been that way long
and you were loosing pressure, you'd see some soot around
it from the exhaust.
Regards Sonny

[Tennjack]

Originally Posted by Monk

Kewl... get that taken care of tomorrow! Now then... how serious is it that I've been runnin' it with no back pressure on that rear cylinder for God knows how long..?

Thanx guys! You da man!

just dont over tighten the thing .

[Rockerbox1]

years ago they always said short pipes were bad because of cold air reversion, it could warp valves, etc. so I would think it you had run that like that too long, you would have noticed something. Decel popping, etc.
and lke already mentioned, carbon deposits all over everything around the head.

[Monk]

Well, oddly enough, I did notice a few strange things starting about a week ago.
The last 2 tanks of gas got barely 30mpg, so that had me wondering... The tank in it now I was measuring very carefully, but think this probably fixed that.
Also I'd noticed a warm breeze from under the front of the saddle the last week or two, but being new to sittin' on one of these, didnt' think much of it.

Also there is a little dirt/oil on the top rear of the engine case I never saw before...

So there were little symptoms that manifested themselves. but didn't add up 'til yesterday when I looked close to see if I could see where the hot air was comin' from.

Anyway, got the nut replaced with a nice grade 8 nut and lockwasher. Had to pull the V&H pipe guard loose to get the right angle, but did it, got the V&H shield back on.

Looks good, and sounds a lot different all of a sudden... exhaust note deepened considerably at once, so now I'm thinkin' the danged thing might've been loose since I bought it 3 months ago.
I'm sure it had both nuts then, I definitely looked, and it was one thing I could identify with my limited knowledge base at the time.

We'll see how this fix affects things... gotta clean the engine reeeal good now.