What are these plug welds for?

[Uncle Bryan]

There are a set of plug welds on the lower portion of the back bone between the rear motor mounts. What are they for? Is there a doubler or sleeve inside the main tube??

 

[racerdave]

Rear engine plate mount bolt holes. This photo is stolen from member pregrid. It shows you the plate bolted to the frame and motor.

 

[FB71]

I don't think he means the engine mount bosses - He asking about the two plug welds in the tube below the bosses - yes, tube in a tube construction

 

[TwoManyXS1Bs]

You can kinda see them in gggGary's 'later frame' pic:

http://www.xs650.com/forum/showpost.php?p=349271&postcount=29

I don't see them in my early '71 frame:

http://www.xs650.com/forum/showpost.php?p=349616&postcount=39

 

[gggGary]

So you think someone is going to run out and chop up a frame just to satisfy your curiosity?

 

[gggGary]

That would be crazy. No one in their right mind would do THAT.

Wait for it..............

 

[gggGary]

Well it just so happens that you're on the RIGHT forum.



Anything to avoid the million projects I SHOULD be working on.

 

[ippytattoo]

Hey gggGary it would seem that, like the rest of us, you are not in your right mind. I like it

 

[gggGary]

Rear engine plate mount bolt holes. This photo is stolen from member pregrid. It shows you the plate bolted to the frame and motor.

That pregrid was such a slacker, what a mess.

 

[fredintoon]

- - - Anything to avoid the million projects I SHOULD be working on.

Hi Gary,
thanks for posting the Sawzall X-ray. When I first got my Heritage I wondered why it would be 100 lbs heavier than my BSA plunger frame Gold Flash; essentially the same bike, eh?
My first guess was that Yamaha forgot to hollow out the frame tubes.
Then I tried lifting an XS650 engine unit the same way I lifted the BSA's semi-unit engine & tranny but the XS unit just stayed on the floor despite my best efforts.
So I thought, "it must be all those massive flywheels, not the frame after all."
Then I saw your photo and realized, "yes, they did hollow out the frame tubes but then they started to fill them up again."

 

[racerdave]

I don't think he means the engine mount bosses - He asking about the two plug welds in the tube below the bosses - yes, tube in a tube construction

Duh, didn't look past the mount holes

 

[TwoManyXS1Bs]

gggGary, Excellent! You're right, this IS the right forum!
You definitely earned a beer and brat for that one...

 

[crazyorigin]

Them welds make it more better, and more strongerer.

 

[gggGary]

OK 2many I cut a late frame, you can chop open an early frame for us so we can SEE the difference.

See? I am an angle grinder guru!

 

[TwoManyXS1Bs]

OK 2many I cut a late frame, you can chop open an early frame for us so we can SEE the difference.

Uh, well, (shuffle, shuffle), I went out there and prodded thru the exposed downtube of the XS1B opening with a long fine wire.

Sure 'nuff, it's all hollow in there, no reinforcing tube.

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