'72 WR exhaust port, inlet reeds and crankcase weld

Hi,

Whilst the frame is off for powder coating I thought i'd have a look at the engine. All seemed ok except the exhaust port looks to be modified with a dremel and there is weld in the left hand crankcase just below the kickstart pinion gear. I can't see how it would have been damaged as there are two welds that are just over an inch but with no weld joining them, ie nothing has broken off and been welded back in. Are both these things out the ordinary? Also there are no inlet reed vlaves but the aftermarket manual says there should be a reed valve in there but i can't see how I reed assembly would fit into the inlet tract.
Please see photos attached.

Thanks in advance.

Exhaust looks as though smoothing was done - OEM has a bit of a drop-off.

Any welding on the outside of the case - on the other side of the kickstart gear housing? The welds may be to stop any cracking that may have occurred.

Big case 72 250 did not have a reed valve - not until 74 with the smaller case Mag motor.

Thanks for the response Vinskord.
No there is no welding on the outside of the case or on the other side from what i could see. It wouldn't have been done at the factory would it? i wonder why it would've cracked as it appears to have done few hours. The bike is very original, even down to the tires and original brake shoes. The rims have no marks etc.
Ah ok, that explains the reed valve confusion and yes the smoothing out does look DIY.

A bit of a mystery - not sure the factory would take the time to weld vs toss a bad part - labor (and time) to weld would cost more than using a good new part. Attached is a pic showing a good used part.

What are the first 4 digits of the motor #? Also, on the bottom of the motor toward the front motor mount, are stamped numbers - are they the same on both the right and left case? These are the numbers stamped by the factory to indicate a matched set of cases.

It is peculiar. I can't see what would cause that to crack there anyway. I forget the the number but yes i did notice the numbers are the same. I'll have a look when i get the chance and get back to you. i don't think the welds will affect anything, its just a bit disappointing when i bought this particular bike due to its low hours.

I know it's been a while but i thought i'd shed some light on the crank case weld.
As i've been struggling for time to look at the engine I dropped it to a well known off road guy. He phoned back the next day to say the engine was never going to run in the current state. It looked to have seized at some point as the piston and barrel were badly scored, the crank was damaged and the cases had been welded together after what looks to be like completely breaking. So the weld i could see was the tip of the iceberg. He said it would be unwise to re use crank cases as the bearings may not be square so a pair of used cases, used crank, new piston, rod and all bearings were ordered and he's going to put it all back together.