70s schwinn speedster project.

If you told them 6mm x 1.25mm They won't have it because it don't exist :LOL:

you want 6mm x 1.0mm all thread
Yeah, I mentioned that pitch being 1.00 on the M6 to him already on another post...lol.

I think you might mean M6 x 1.00 for the 48cc.

I could be 1.25 but tI don't think so on the M6 size metrics.

Maybe someone else will know for sure before you order a helicoil kit like this one below.

https://www.amazon.com/BILITOOLS-M6x1-0-Thread-Repair-Helicoil/dp/B09WN4XSVV
 
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Okay, now I'm officially a little bit unhappy. I bought a bolt, 6mm wide, 1.00 thread pitch, 100mm length and it fit perfectly, however when I went to torque down the head studs two more of the stock studs snapped. I'll get some more of the grade 8.8 bolts tomorrow after school and work.

My best guess as to why these are shearing off is that I used lock washers under the acorn nuts. Just going to replace the last stock head stud with the hex bolts while I'm at it. Not making the same mistake and there are no washers of any kind going under the new bolts.
 
Okay, now I'm officially a little bit unhappy. I bought a bolt, 6mm wide, 1.00 thread pitch, 100mm length and it fit perfectly, however when I went to torque down the head studs two more of the stock studs snapped. I'll get some more of the grade 8.8 bolts tomorrow after school and work.

My best guess as to why these are shearing off is that I used lock washers under the acorn nuts. Just going to replace the last stock head stud with the hex bolts while I'm at it. Not making the same mistake and there are no washers of any kind going under the new bolts.
I like the button head allen bolts. They have a good contact area and look nice.
 
Okay, now I'm officially a little bit unhappy. I bought a bolt, 6mm wide, 1.00 thread pitch, 100mm length and it fit perfectly, however when I went to torque down the head studs two more of the stock studs snapped. I'll get some more of the grade 8.8 bolts tomorrow after school and work.

My best guess as to why these are shearing off is that I used lock washers under the acorn nuts. Just going to replace the last stock head stud with the hex bolts while I'm at it. Not making the same mistake and there are no washers of any kind going under the new bolts.
You made the cardinal sin of thinking that just one of the studs was bad. If one breaks, the others are due.
 
New studs in. The resistor plug fixed the interference problem.

I go to adjust the c clip and now the spring wont return the throttle closed. Works off the carb, soon as I put it in, the throttle is stuck wide open. Returned the clip to the original position and the problem is still present.
 
New studs in. The resistor plug fixed the interference problem.

I go to adjust the c clip and now the spring wont return the throttle closed. Works off the carb, soon as I put it in, the throttle is stuck wide open. Returned the clip to the original position and the problem is still present.
The slide has a little groove that fits a pin in the barrel. If you rotate the slide it should drop in to it's groove and all should be good.
 
New studs in. The resistor plug fixed the interference problem.

I go to adjust the c clip and now the spring wont return the throttle closed. Works off the carb, soon as I put it in, the throttle is stuck wide open. Returned the clip to the original position and the problem is still present.
The slide has a little groove that fits a pin in the barrel. If you rotate the slide it should drop in to it's groove and all should be good.
@robe has pointed out the most obvious cause of this problem...That little nub inside the round chamber is on the right side, the direct opposite side from where the Idle screw is about half way down the round barrel aperature for the barrel slide...The nub protrusion must be inside that long groove on the black barrel slide assembly so it will slide up and down freely.
 
I fixed the carb issue. The venturi was just flipped the wrong way around. I played around with using spacers to raise the front, hypothetically it solves the issue with chain clearance. I want to forgo a tensioner but it maybe required given how high the engine must sit for a barely comfy chain clearance.

I had tried to make new struts for my rear rack and it lacks rigidity. For the sake of getting this thing running before it starts to snow I am putting the stock tank back on it. The stock struts were just rod stock with the ends forged flat. Shouldn't be too hard to copy if I get ahold of a propane torch.

A giant spacer wouldn't be too bad to fabricate. Punch, drill, flip and repeat. Would have to be 2 7/8' long though. Either that or a new jackshaft mount that keeps it roughly level with the front sprocket. higher. For now a chain tensioner will suffice.
 

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I thought I had fixed all the problems: sorted the seat, got the chain to clear the frame, got the old tank on it. Wheel in the air, all three speeds ran right. Worked walking it along in low gear. Evidently the engine decided the mounts weren't up to snuff when I had tried to ride it and accidentally dumped the clutch.

Jerry was right about the gearing though, it was a little anemic walking it along.
 

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