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#2 Exhaust fouling frame

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JamesH:

--- Quote from: Lobo on November 05, 2023, 11:22:43 AM ---Ran out of time 1/2 through today, but got #2 pipe off and am struggling to see how to  get the clearance I want - and figure I’m going to have to SLIGHTLY grind it’s ‘hanger hole’ so it butts to the frame off-square…. and ‘tilts’ the exhaust inwards a few degrees.
What’s really confusing me is that I’ve owned / been intimate with this bike and its HM341 pipes 10yrs now, and never been aware of this issue. I stripped it completely down last year, there was no rub / witness markings evident in either the frame nor exhaust - so what gives??? The only 2 things that changed in the rebuild are the newly powder coated frame, and my ‘plastic sleeving’ the footrest bolts as they had excessive vertical slop.

--- End quote ---
Lobo - have you removed/refitted the exhaust spigots that bolt to the head and crush the copper gaskets? A minuscule change in the alignment of these leads to a big change at the exhaust hanger end..   

Lobo:
Thanks James - yep, I have removed it; the crush washer is crushed evenly. Are you saying that if I set the silencer as wanted, and only then tighten down the spigot (sympathetically) it’ll work out? (have a set of new crush washers at the ready - not keen to use ‘em until I’m certain of a positive result!)

If I understand this correctly, the #2 exhaust muffler connector will subsequently loose vertical alignment with #1 - ie presumably I’ll have to refit / realign #1 exhaust spigot?

(Accepting it’s a different exhaust part #; I looked under my Sandcast and note the pipes well clear of all frame paraphernalia - which only added to the confusion)

Anyways - appreciate this new info and will try again later in the week.

JamesH:
Was just a thought really lobo.

I'm currently having an alignment issue with a reproduction no.3 exhaust from Busso (thread on the US site). I'm just challenging my own thinking, really, so thought I'd put it out there. The problem with access to the spigot screws is it's difficult to get purchase on them with the exhaust clamping crowns fitted; so playing around is a bit of a bugger - and you don't want to introduce an exhaust leak into the equation once they've been clamped/crushed intiially.

I guess I was just trying to see 'what's changed' with your setup and if that's contributed.

Logic doesn't always seem to apply to these bloody exhaust systems.

Lobo:
Thanks James. Tbh I’m not having problems with the spigot screws as using a very nice long Allen wrench which fits in between the clamping crown fins.

I’ll play with your suggestion, but basically feel those spigots are engineered to clamp down squarely (against the crimp rings) in order to guarantee a seal. We’ll see… otherwise it’ll be something a bit more significant 😱.

Still struggling as to ‘what’s changed’.
Ta. Simon

Johnny4428:
Good shout James about the exhaust spigot. Having given a bit more thought into these exhausts fouling frame and engine oil filter housing I wonder if the boss on the silencers are not the correct width which could make it fit badly. In my case I had to pack an extra couple of oversize washers on the inside of frame to take up the slack ad the threads were bottoming out and the footrest on the outside was flopping about still. Think I’ll try the washers between the outside of frame and the inside of the No2 silencer boss.

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