850 Commando cylinder base and head torque

Hello All,

I got my very first Commando 1974 850, and now its time to retorque the cylinder barrel and head. I have removed the top head stay to ensure access and accurate torque.

I am sure that this has been covered many times, but for the life of me I am still unclear. I do have the factory service manual and parts book, but still want to be certain.

I count 5 cylinder barrel bolts (3 at the front, and 2 at the rear), inspite of the fact that my factory service manual shows 9.

How many cylinder base bolts for a 1974 850?
How many cylinder head bolts for a 1974 850?

Thank you very much,

David

The 850 has 4 barrel through bolts which you only see when you take the head and head gasket off so the 5 you see becomes 9 that on a 750 you would see without taking the head off so you can't re-torque them without taking the head off. It's all covered in the workshop manual but you need to read it through to make it clear as it only mentions this after the head is off. If you look at the diagram (Fig C2 in the one I have) that looks like a head gasket it identifies 10 head fixings, some come from above the head but some come from under the head through the barrel these are 2, 9 and 10 on fig C2. For the head torque values are 5/16" 20ft/lbs, 3/8" 30 ft/lbs but some you have problems getting a torque wrench on to without crow ft extensions.

"How many cylinder base bolts for a 1974 850?
How many cylinder head bolts for a 1974 850?

Thank you very much,

David"


There are 9 cylinder attaching bolts/studs. 4 of them are only accessible after removing the head.

There are 10 head attaching bolts/studs. 7 accessible from the top and 3 from below. Jim

Thank you boys!

Now that makes sense.


David