Yes auto is right the ball berings in the lobes of the cam are compression releases !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Continuing with the theme of this thread, here are some photos of the drive dis-assembly. First, removal of reverse disc caliper and debris guard removal. First, remove the engine cowling....good luck with that. Make sure to keep track of all your bolt locations. The debris guard with now be exposed, so you want to remove that next to expose the crankshaft. Next few posts will walk you through the rest of the dis-assembly process. One cannot load more than 3 photos in any one post.

Revers Brake Caliper Removal.jpg

Brake Caliper Removal 4.jpg

Debris Guard 1.jpg

Next secure the crankshaft with a c-clamp and remove the end bolt using either impact wrench or breaker bar.

c-clamp used to secure crankshaft.jpg

End bolt removal 1.jpg

Once you remove the end bolt the disc assembly will slide right out without much help. Sorry about the quality of the first photo. After removing the brake disk you will expose the first part of what I'm calling the belt gearing which you see in the second photo. Those are 3/16 hex nuts. Unscrew all of them and that part will drop out exposing the belt pulley which is shown in the third photo.

Brake Disk removal.jpg

Belt Gear overview 2.jpg

Belt Gear Removal 3.jpg

Removal of the belt pulley and clutch was difficult and required a three pronged puller. First, remove the anti rotation bolt as shown in the first photo. Loosen the nut situated right up against the crankcase cover first, then loosen the bolt. Next, loosen the engine mount bolts so you can pivot the engine back to release tension on the belt and remove it from the pulley. Make sure to cover the belt shaft so nothing falls in it. It's probably a good idea to have covered before this point, too. Then use the puller to pry loose the clutch and pulley together as shown in photo two below.Then you are left with what is in photo 3. The pulley is going to fall off the shaft first so make sure you catch it. The clutch will come off next.

Belt Pulley and clutch stop bolt.jpg

Belt Pulley and clutch removal1.jpg

Belt Pulley and clutch remoav 2.jpg

When one removes the clutch there is a spacer washer behind it. Don't forget to reinstall that when you re-assemble the drive train. I notice when I was reinstalling it that the inside of one side of it is tapered. If you'll notice in this photo below, the crankshaft expands a bit at the crankcase cover so I presumed the tapered side of the washer faces the engine. I'm not certain of this cause I didn't notice the taper when I removed the washer from the shaft. I presumed the flush side of it butted the back of the clutch.

Washer Behind clutch.jpg

So up until now you have directions for dis-assembly of the complete drive train for a GTR23, and its probably the same for a GTR35. Next comes the Crankcase removal.

Drain your crankcase oil first!!!!!!!!!

Detach Governor shaft from governor lever.

Detach dipstick from crankcase cover.

Unscrew all the bolts from the perimeter of the cover. The one at the very bottom middle cannot be reached without lifting the motor off of the motor mounts, unless you have a real small socket wrench and then It may still not be accessible because it is recessed to much. It does not really matter, on second thought, because you stiff have to unbolt the motor mounts to take the drive belt off of the pulley.

I used two prongs of my puller and two crankcase bolts positioned in opposing auxiliary crankcase holes to pry the crankcase loose as in the third photo. Again, you have to lift the motor off of the motor mount bolts and set it sideways on the frame platform to pull the crankcase all the way off, otherwise as you can see form this photo, the belt housing does not permit the crankcase cover to clear if left on the frame bolts.

Governor overview 4.jpg

dip stick removal 1.jpg

Crankcase Cover Removal with puller.jpg

Once the crankcase cover is removed here is what you will see in the first photo. The gear with the ball bearing in the center of it is the stock cam. The small disc below it on the crankshaft is a washer that floats over the ball-bearing gear on the crankcase cover. Before you pull out the cam, loosen the valve rockers and unseat the push rods to remove pressure from the cam lobes. Now ull out the cam. The second photo is a shot looking directly at the space vacated by the cam once its pulled out. The slot at the very back in the center of the photo is the receptor for the shaft end of the cam, and the cam gear sits on top of the teeth of the gear in the bottom of the photo. Notice the "dot" indention on the to tooth in the apex of the shaft gear. One matches that dot with a similar one on the female spot of the cam gear to align the cam properly.

Caution: When you pull the cam out, the push rod tappets might fall and the push rods will drop into the crankcase compartment, but won't fall out all the way. When you insert the new cam, you will have to reinsert the tappets and push rods back into their holes.

Crankcase overview 1.jpg

Crankcase view of cam slot 2.jpg

Just reverse the process to get things back together. Make sure to:

Shim Valve springs
Put assembly grease on cam lobes and grease bearings
Fill motor with Oil
Fill reverse gear with oil.
Rig throttle assembly cause you no longer have governor
Prolly install rev limiter
Break in at 2500 RPM's for 20 minuets.

When shimming valve springs, you will have to insert compressed air into a vacated sparkplug hole to suspend the valves while compressing and removing the valve springs, otherwise the valve will fall into the piston cylinder (thanks to MMT member for this information)

just asking but insted of spending all dat money in dat motor why not spend a little more and put a 35 on dat frame?

This site kind of basically explains it. Works off of centrifugal force.. It keeps the exhaust valve slightly open when cranking. As the engine starts and RPMS increase the ball moves away and allows the valve to operate nromally. These are built into the camshaft.

http://www.sscycle.com/feature/featureview.php?s_id=10

Awesome thread.

u got!!! Hey guidry if u dont mind take a clean picture of the back of the clutch of the white tag with the number's on it please if u dont mind!!!