Topic: Cb400four, broken exhaust stud

[radarlove]

I just picked up a '75 cb400four, with 6,000 miles. The bike is really clean, but someone knocked it over before i took it home, dented the pipe and broke an exhaust stud. My might was too novice to get a Heli Coil to work right. A knuckle head tried drilling the hole out with an easy out, and now i believe i need to weld the hole up and re tap it.

[radarlove]

More pics!

[Don R]

Aren't the split clamps on backwards?

[radarlove]

Probably, thanks!

[MoMo]

split collars are on correct

[NobleHops]

I just picked up a '75 cb400four, with 6,000 miles. The bike is really clean, but someone knocked it over before i took it home, dented the pipe and broke an exhaust stud. My might was too novice to get a Heli Coil to work right. A knuckle head tried drilling the hole out with an easy out, and now i believe i need to weld the hole up and re tap it.

See if you can get the helicoil out cleanly, and measure the hole. It's a longshot but you might have enough meat to tap for a TimeSert. I tried and failed to see what the diameter of the drill is in the 6mm kit, but with a bit of digging perhaps you can find out.

https://www.belmetric.com/timesert-metric-kits-inserts-m6x10-c-217_218_228.html

[iron_worker]

Or:

http://www.timesert.com/html/bigsert.html

IW

[NobleHops]

Or:

http://www.timesert.com/html/bigsert.html

IW

Oooh, did not know about those, very cool.

[radarlove]

i rebuilt the carbs and got it running well with a temporary fix of tie wire holding exhaust on, just so I can identify as many issues before tearing it down. It's a shame it was damaged, but at least I have another basket case that's might come in handy.