Hey fellas, need some help. Am re-assembling and am putting the inner primary/chaincase back on. After lightly snugging up the three lock-tabbed bolts that connect the chaincase to the crankcase, there is no gap between the centre bolt.

I was tightening up the three bolts but am scared shitless I will strip them in the crankcase. Is there a torque setting involved here?

I have snugged them up but they always seem to turn a bit more. I was careful but am wondering if I have already stripped them...

Thanks!

Old Britts has a list of torques: http://www.oldbritts.com/n_torq.html

It shows 60 to 80 INCH pounds which isn't very much, about 5 - 7 foot pounds. Dunno what to tell you about maybe being stripped. Might want to pull the case back off and get a look at them, then try the bolts without the case to see how they feel. With that light of a toque setting I might try some kind of alumi-weld epoxy if you need to repair the threads.

Russ

rvich wrote:Old Britts has a list of torques: http://www.oldbritts.com/n_torq.html

It shows 60 to 80 INCH pounds which isn't very much, about 5 - 7 foot pounds. Dunno what to tell you about maybe being stripped. Might want to pull the case back off and get a look at them, then try the bolts without the case to see how they feel. With that light of a toque setting I might try some kind of alumi-weld epoxy if you need to repair the threads.

Russ

Mine are all helicoiled (not by me). I'd just snug them and then take advantage of the lock tabs.

Thanks Russ

I snugged them on a bit more and then bent the tabs over as best as I could what with the messed up angle for the punch.

Tried to put the engine sprocket/clutch sprocket on as well but the chain is incredibly taut. I left it as the neighbourhood kids were learning some real bad words from me!

Not sure if I should slacken the gear box to get it on or if they are supposed to be this tight.

Have you had things apart far enough that the gearbox adjuster would have changed? If not then you should be able to slide it back on, assuming of course that it wasn't bone tight when it came apart.

I am not shure about 750's , but on 850 these holes are helicoiled from the factory .
I think you'll break the bolt first before stripping the thread in the case .

As noted, snug is sufficient - a dab of something like Permatex Ultimate Gray Motoseal (or Yamabond, Hondabond - same thing) on the bolt threads is a good idea since oil from the crankcase can seep around the bolts and leak on the ground/into the chain case.

B-Stone wrote:Hey fellas, need some help. Am re-assembling and am putting the inner primary/chaincase back on. After lightly snugging up the three lock-tabbed bolts that connect the chaincase to the crankcase, there is no gap between the centre bolt.

The center bolt hex stud should have shim washers to align the inner primary case parallel to the engine mounting plates. You need to dry assemble the primary case, including the crankcase gasket, and measure the gap there with a feeler gage. Then choose the appropriate shims.

Tried to put the engine sprocket/clutch sprocket on as well but the chain is incredibly taut. I left it as the neighbourhood kids were learning some real bad words from me!

If the inner case is shimmed too far out the engine twists to the right in its mounts and will make the primary chain tight. However, normal chain slack is only 3/8" total up & down movement, so you do need to "wiggle" things together.

Make darn sure that the inner primary is flush at the crankcase and touching the chaincase centre stud with a good gasket. If there is a gap at the front of the crankcase, shim out, if gap is at the back of the crankcase, remove shims. At has to be right.

At hobot's suggestion, I replaced the 3 crank bolts with 1" studs and nuts. Then you can red locktite the studs into the crankcase to prevent leaks, blue locktite the nuts, and it is easier then to install the gasket, and the inner cover. You will have to grind down the bottom 2 studs so they don't stick out past the nuts and interfere with the chain. I test fitted my inner cover and I ended up putting 2 washers on the center bolt outside the inner case to take up the space. If the inner case is tight against the center bolt, the engine must not be mounted right or something is out of kilter, as far as I know they all had some space in there.

Dave
69S

Thank goodness it don't take much to hold on inner cover. It the threads are shot then thank goodness for helicoil or better Timeserts or even a necked set of studs bigger in crank case same size through primary case. You got the details above.

BUT BUT BUT you are in extreme danger to damage Whole Drive Train with the triplex chain ever in tension instead of floppy loose bottom run. It was tense when cold then its too late - you have already bent your main shaft if its been run to operating temperature and given enough throttle to get to traffic speed.
Always check chain when hot for some slack then feel how sloppy loose it is cold
and remember for next cold tension adjustment. Yes back off gear box and hope
main shaft and sleeve bushes give some mileage before digging in there too.

Commando are only for a matured man to tackle and can rebound again and again from the learning curve failures.

hobot - still rebounding, one more time then admit I'm whipped and give someone else a chance at a decent Commando life.

hobot wrote:
Commando are only for a matured man to tackle

I guess that leaves out most of us...

Slacked off the gear box bolts and rear chain completely in order to finally get it on. The gearbox moved forward on the eyebolt (right) side but on the left side (primary) it didn't slide back hardly at all. Because of this it was still a tight squeeze.

Not sure why the gear box did't move forward equally on both sides.

Do you have the upper gearbox spacer correctly mounted. Item 34 here http://www.oldbritts.com/1971_g5.html

If not that will throw things out of kilter.

Dave
69S

You might be on to something here.

I have attached a couple of pics