Today class, we’re rebuilding my Triple engine. Dont know how long its going to take me but some pretty pics with words surely will help others rebuild theirs later on…

I know this has been done in the past by other forum members, but I’m going to show my engine getting rebuilt from scratch!

1st of all we start with the crank case top half…
I had my top half sandblasted and repainted with Hi-temp black paint


Turn it over and let the fun begin.
Install the kickstarter gear. Manouver the shaft in, and line up the clip into the case and install the holder and the allen bolts. Then put the gear on with the washer and circlip


Next we’re going to install the bearings.
Now in my case, the crank was linshed and the rods were resized and completely cleaned up by a machining shop.
They even had to remove the balls on the sides of the crank to clean out the crap that had accumulated behind and into the crank.
The machine shop said for me to use the biggest size bearings - these are the ones Yamaha marked blue. I was advised to put the new bearings in and torque the cases up and make sure everything spins freely. You probably wont need to do this, but its always good to dummy assemble like this…

Anyways here I learnt that Ebay is your friend… Bearing shell kits, a LOT cheaper than paying the arm or leg that Yamahaha charges!



Install the bearing shells into the crankcase, dont forget about the sidethrust bearing



Apply oil to the bearing surfaces:


And carefully place the crank into the case


Next get your nice clean rods, install the bearing shells and apply oil to the bearing surfaces.




Assemble them onto the crank and carefully tighten the rod bolts to the required 27 ft lb


Rods are on!


Now gently lift the crank and insert the rods through the holes into their correct position


Thats the top half done! (well for now)

Next Insert the bearings into the crank case bottom half, and apply oil to the bearing surfaces!


Insert the case locating dowels, disregard the one in the middle there… its just there for looks and isnt actually needed at all


Put the cases together!


Install bolts numbered 1-10. Then tighten in 2 steps with your torque wrench to the specifications in the book
1st stage i think is 16 ft lb for bolts 1-8 and 7 ft lb for bolts 9-10
2nd stage is 27 ft lb for bolts 1-8 and 14 for bolts 9-10 (will check book later to confirm these numbers)


Now turn the crank, make sure everything spins freely with your new bearings etc etc


All Fantastic!

Now pull it apart again!!
Losen bolts 1/2 turn in reverse order to how you installed them, and then remove them in that order.


And now we’ve got the 2 crankcase halves separated - Top half with the crank still sitting there, and bottom half ready for the transmission to be installed.


Put the top half with crank aside, as its not needed for a little while, and be ready for the next part - Installing the transmission!!

Ok… I cheated a little bit, as you may have seen in a few of the above pics, some of the transmission was already installed when I started!

I’ll tell how to do it anyways…
Install the shift cam


Install the detent bolt and neutral switch


And the locating bolt


Manouver the gear shaft into place


Place the clip into the grove on the bearing, and install the cap so the clip sits in the grove and holds the bearing in the correct position


Insert the shift forks onto the 4th and 5th gears and line the pins up into the shift cam
Insert the fork shaft through the RHS of the engine so it passes through the gearshaft cap, add the washer, and push the shaft through the shift forks.


Install the E-clip, making sure it holds the washer against the gearshaft cap.


The SF model has a lock-bracket to stop the nuts from working loose. Place the lock bracket over over the studs, and apply loctite to the threads.


Install the nuts and torque to correct specification of 14 ft lb
Carefully bend the lock tabs up very gently by hitting a screwdriver against them with a hammer so they’re locked in place. The tabs break easily, notice one has already broken off!


Apply loctite to the layshaft bolt


And install it with the spring washer and plate washer into the countershaft


Hold the gearshaft with a big screwdriver, and torque the countershaft bolt to 18 ft lb


Next, Install the main gearshaft


Add the shift fork, insert the bar and install the E clips as shown here


And here


Next, install the Clutch pushrod seal. Apply some grease to the lip. I’ve run some gasket sealant around the outside of the seal


Next add the middle gear assembly. Take note in the book of how the circlip halves sit. Again with the seal, Ive applied gasket sealant around it.


Again apply oil to your bearing shells


And place the crank into the case


Dont forget to add this O-ring!


Apply gasket sealant to the mating surfaces of both crank halves


Carefully join both halves together, check the locating dowels have inserted properly.


Next, carefully turn it all over and start installing bolts 1-14 in the correct numbered pattern, and then torque them in the two stages again.
Torque stages for the bolts are:
1st stage, bolts 1-8 are 13 ft lb. Bolts 9-24 are 7 ft lb
2nd stage, bolts 1-8 are 27 ft lb. Bolts 9-24 are 14 ft lb


Turn it over and do the same with bolts 15-24, and again torque these in two stages.


Then install the last bolt which goes in the RHS above the layshaft bolt


Now there you are, assembled engine crankcase, waiting for more!


Next up will be the installation of the clutch components, the electric starter gears and the pistons/cylinders/head etc
Like I said, this may take me some time (well the rest definitely will) so keep checking for updates, and feel free to comment!!