How tight must cylinder head be?

If you're stripping out the nuts or the studs on your engine, then you can't be turning it on right. If you can't easily screw on the nut by hand all the way, then there is something impacted in the threads and it has to be addressed. Acorns and stainless aren't very good for engines, acorns because some times the studs are left a little proud of the surface and the nut bottoms out before it actually does its job. Stainless, because it can't stand repeated heat cycles before it becomes brittle.
What metal type do you suggest?
 
What metal type do you suggest?
Just regular steel nuts always work, Home Depot probably have them for a buck or two, no waiting. Another thing with the acorns, if they bottom out before tightening the head, then they start turning the stud in the case. This can lead to the case being stripped.
 
Just regular steel nuts always work, Home Depot probably have them for a buck or two, no waiting. Another thing with the acorns, if they bottom out before tightening the head, then they start turning the stud in the case. This can lead to the case being stripped.
Exactly my thought. This is why I bought coupling nuts instead. The threaded rods extend about 14mm out of the cylinder head, and the coupling nuts are about 25mm so it will create a 11mm reservoir where water can puddle but I dont think its a major concern. Also helps with increased surface area and heat distribution.
 
Exactly my thought. This is why I bought coupling nuts instead. The threaded rods extend about 14mm out of the cylinder head, and the coupling nuts are about 25mm so it will create a 11mm reservoir where water can puddle but I dont think its a major concern. Also helps with increased surface area and heat distribution.
If you want to take up unused thread to protect it just use a second nut on each stud as a jam nut. That is exactly what I do with mine after the hardware stopped coming loose from the initial heat cycling. I actually used acorn nuts as my jam nuts ironically lol.
 
If you want to take up unused thread to protect it just use a second nut on each stud as a jam nut. That is exactly what I do with mine after the hardware stopped coming loose from the initial heat cycling. I actually used acorn nuts as my jam nuts ironically lol.
That's about all they're good for. If it's not obvious that they won't bottom out, I use a toothpick to measure the depth.
 
Links to Amazon may include affiliate code. If you click on an Amazon link and make a purchase, this forum may earn a small commission.
Installed the new coupling nuts, torqued em to 160 inch / ft and installed a new aluminum head gasket. I am glad I got the torque wrench - 160 inch / ft is less then I would have imagined and I would have over tightened.

I was reading that the rear tire should drag and not rotate when pushing the bike with the clutch not engaged - I was able to get a some movement and piston rotation - does this mean its not 100% airtight / sealed? Or is this normal, possibly air coming in reverse from the exhaust exit or carb entrance?

Vid of piston rotation / tire dragging:

Vid of bike riding (dont hear four stroking at WOT anymore):

..

..

..
 

Attachments

  • 1.jpg
    1.jpg
    139.2 KB · Views: 94
  • 2.jpg
    2.jpg
    152.5 KB · Views: 101
you need to adjust your clutch for sure. @DAMIEN1307 will quote you the official instruction manual, it works. It's not hard. There's also a ton of youtube videos about it. I'm about to eat dinner or I would post some info here.
 
That's all normal, the engine should turn over a wee bit while dragging the wheel. Now that you've ran it check the torque on those head studs again. Do that after each ride for a few rides until they settle in to a full tight position.
 
I was reading that the rear tire should drag and not rotate when pushing the bike with the clutch NOT engaged
When clutch is NOT engaged, the rear tire should NOT drag and the wheel should rotate freely. otherwise you will totally burn out and destroy your clutch.

Here below is how to adjust the clutch properly.

When adjusting the flower nut on the clutch, make sure that you have the clutch lever pulled in and locked in place. (Disengaged)

Tighten the flower nut until you can't turn the back wheel at all, from there, turn the nut counter clockwise a "notch" at a time until you get the rear wheel to turn freely by hand and stop right there and put the lock screw back in place at that notch where the wheel just starts to turn freely.

When you release the clutch lever, (clutch fully engaged), it should of course be totally locked up and at this point you should have it right.
 
Back
Top