Cam cap torquing sequence?

Is there a torquing order for the cams caps? In the manual, installing the cams comes closely after torquing the head & there's a pattern shown for that but I missed it if there is one for the cam caps. All I find is to put #3 with its pegs in first and to place the rest of the caps in their numerical order. It shows the torque value and to tighten the caps in two steps.

Did I miss a specific order to tighten them in?

 

I would guess that it matters as to the exact position of the cam lobes, as one lobe will be compressing a spring, and you would want to start with that cap. You can tighten incrementally, being careful that nothing binds up. Some assembly lube would be a plus. Make sure the motor will roll over before torquing everything to spec, just in case something bound up.

 

Hi Time,

Got the assembly lube.! In the manual it also says to have the dot on the cam facing up. This makes the #5 lobes going down & #1 going up so #1 cap is the easiest to get down but #5 end is so high you can't get the washer and nut on. Other

In the manual it says "The cam caps must be tightened evenly or damage to the cylinder head, cam and caps will result. The spaces between the caps and cylinder head must be equal".

The quote is "Torque the cam nuts in two stages and final torque to the specification" The torque is 7.2 foot pounds.

To keep pressures even I'd think it would be good to tighten all the nuts so they have the same torque but it says to do it in two stages so maybe the first should be to torque each nut to 43 inch pounds and when #5 cap lowers enough to get the washer and nut on, torque those to 43 & then tighten them all to 86.4 in pounds. And hen recheck.

But I'm guessing here at how to choose which to tighten. I've learned the Yama service manual leaves out mandatory details which has been a Royal PITA. So if there's a specific order for the cam nuts, I need to know that or if it's simply any order but with two torquing stages, that's easy.

 

It's pretty much any order but in stages; however TIME's advice is spot on; the order should be determined by which lobe is pressing on a bucket and the need to maintain an "even" draw-down.

 

After thinking about it - if you phased the cams at TDC, there would be 2 intakes and 2 exhausts partially pressing, and you would want to tighten all the bolts so all the caps' edges had relatively the same gap as you snugged down the cams.

After you have everything snugged, you roll the motor, inspect, then do the 2 step torque. (spiral pattern - why not)

Hope that helps.

 

For the informational database that hopefully comes up when someone in the future has the same boggle as to cam nut torque sequence... I got this answer as regards the XS1100 which my XJ1100 is the offspring of that great bike.

"Page 78 in the clymer says 3-4-2-5-1"

Since the Yama manual appears to exclude important trivia such as this either out of ignorance, avarice* or arrogance... forums like this one are the grail for those of us keeping these marvelous bikes going and going.

* in that failure means take the bike to an authorized Yamarobber for service.

 

They "exclude such trivia" because the factory manuals assume a certain prerequisite level of training on the part of the book's user; unfortunately most of us don't have the benefit of such training. Equally unfortunately, it was a rash assumption in regard to most dealership mechanics as well.

The book says "tighten it down evenly." They assume you know how to accomplish that, no matter how counter-intuitive the process.