TOPIC:

I guess this is the right spot to post a little video.. if not let me know...

The main reasons most 1300/6 overheat is due to a water pump issue. This is assumng you have burped your coolant system and are happy its 100%.
This can be one of many things including the Nylon Gear being damaged, or the Impellor not attached to its shaft at the end due to is being corroded.

If you are confident the coolant is all good and the system has no air in it, then the only other thing to do is to drain the system and take the M8 Drain Bolt out of the front lower Impeller Cover which can be seen and accessed from the front of the engine.
From the correct angle, and maybe using a mirror and torch, you can see UP inside the Impeller Cover / Chamber where a small part of the Impeller itself is visible.
Get someone to turn the engine over on the starter and see if the Impeller is spinning 100% as it should be...............

Hope that helps ?

Pete F
UK

Perhaps a less serous and more logical answer would be a thermostat that's not opening or not opening fully.

If you watch the video showing his bike running with no rad cap it appears that the thermostat is opening as shown by not only the movement of the anti freeze but also by the appearance of the coolant rising in the neck of the rad. At least that's the way it seems to me (may not be opening all the way however it does look to be opening)

Stocktoy,

Thats a very relavent point.

What we dont still know is of the coolant system has been BURPED properly yet ?

Pete F
UK

strate6 wrote: The main reasons most 1300/6 overheat is due to a water pump issue. This is assumng you have burped your coolant system and are happy its 100%.
This can be one of many things including the Nylon Gear being damaged, or the Impellor not attached to its shaft at the end due to is being corroded.

If you are confident the coolant is all good and the system has no air in it, then the only other thing to do is to drain the system and take the M8 Drain Bolt out of the front lower Impeller Cover which can be seen and accessed from the front of the engine.
From the correct angle, and maybe using a mirror and torch, you can see UP inside the Impeller Cover / Chamber where a small part of the Impeller itself is visible.
Get someone to turn the engine over on the starter and see if the Impeller is spinning 100% as it should be...............

Hope that helps ?

Pete F
UK

Thanks for the reply, Pete. I have very good flow through the radiator as seen with the cap off. The water pump has been rebuilt, thermostat tested, new one procured and tested, installed, no difference. Bypass is open, pump doesn't leak, this is freshly built engine.