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Discussion Starter · #1 ·
I have what i think to be a 71 , it says inside the head under the rocker cover. I would like to put 1-5/8" exhaust on them. I saw an adapter for push in style 750 heads to accept normal 650 exhaust , are the holes the same size or are there other adapters for the 650 head? thanks Loffer.
 

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the push in spigots are the same diameter as the screw in Ken, my motor is a 72 w/push ins, and i'm running 1-5/8 pipes, the pipes just step down a bit after the collars.
 

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Discussion Starter · #7 ·
I BOUGHT A set of the push in exhaust manifolds for . They are listed for 750 for but are the same diameter for the head basically. They are not a direct fit. I heated the head and one slipped in without much resistance after claening both surfaces, the other no go. I sanded the collars a bit as good as i can by hand and one side is still large.

I was thinking of having one milled down to fit better it would be a very minimal amount , does this sound like a good way to go? I cleaned the exhaust ports with a hohning type sanding bit and they are clean and smooth . Should i just keep working the one thats large with emery clothe till it fits it wouldnt take much I guess maybe an hr. VS taking the head and spigot to a machine shop and having them work on it? I seems it should be added when heated for it to stay permanantly or could this cause problems? The outer parts of the spigots are kinda large too making it a pain to put the exhaust on they dont need to be so tight when you have exhaust clamps, so they need to be worked a bit too. the I could sit there and sand them by hand for a couple hrs and go that route. I have done it before making stuff fit, not every piece/pulley fits into a lathe, PITA. thanks in advance. More concerned about expansion...
 

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Yea never liked those push in either I weld in spigots or I get exhaust from england that slide in head I have had the old spigots threaded with good results on 10 bolt heads
 

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Discussion Starter · #9 · (Edited)
Yea, skinner. I went ahead and sanded them down ok a belt sander and finished
with emory clothe. I did it a few time and heated and got them to seat with a couple light taps of a rubber mallet . I dont den kniw why I ask half the time cause I never wait for advice if i have an idea I'm comfy with. They are pretty snug , as good as the threaded ones. I imagine they will work as torque cones for the big pipes cause the opening from the exhaust is under 1.5 id now with 1.75 pipes. I have a couple sets of tt pipes I'm using thy are my fav pipes . So much better quality than the new stuff.
 

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Loffer, FYI, the number on the head(71) is the year it was cast.Generally that number is 1 year ahead of the year model of the motor. So it is a 72 head. Jack
 

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on an old 750 I had the ali' spigots/stub that pushed in had a knurled finish to hold them there.

eventually I had them Tig'd to the head because they would work loose.

Good fix while I had te bike, but if they ever got worn major head ache would be that they would have had to been machined out in order to replace.

6 of one, 1/2 dozen of t'other.
 
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