107 top end rebuild.

[mittens]

Rear jug head gasket is leaking some. Never had motor apart before. I have the primary & rebuilt the trans, & everything else on-the bike I have. So here we go. Ordered top end gasket set, valve seals, rocker box gasket set, new boots for compression releases, & a cam cover gasket from Curtis/ WSW. I plan to pull it to see if the factory 520 EPA cam is still in there, or has it been swapped before. If stock will go with a .600 cam while I am here. I want to give everything a good cleaning & polishing while it's apart. I take lots of pics of everything I do so figured why not start a thread of progress. Maybe someone will find it useful/ learning tool. I know pics help me. I know I will have my own questions as I go too.
Today had to replace the China motor on car lift, got my 66 back out the way. Then put bike on lift, got it down to the rocker boxes. Carb, intake manifold, jugs, heads all need polishing. Bike ran great just wanted to address leak & cleaning. Plan to clean valves & top of pistons everything I can get to.

 

[Jwooky]

I would not use the 600 unless you deck heads/jugs and do the bigger valves. It will hurt more than help otherwise.

If you don’t want to go that far, use the 585.

 

[knothead]

I have a BRAND NEW 600 cam I will sell you...they cost 250 but I sell this one for 225.00 free shipping if your interested

 

[mittens]

I

I would not use the 600 unless you deck heads/jugs and do the bigger valves. It will hurt more than help otherwise.

If you don’t want to go that far, use the 585.

though everyone loved the 600 cam in a 107 & it was the choice to do for power & reliability. First I have heard don't do it.

I can deck the heads if need be too, but probably not going to spend the coin to change valves.

 

[Jwooky]

I

though everyone loved the 600 cam in a 107 & it was the choice to do for power & reliability. First I have heard don't do it.

I can declare heads if need be too but probably not going to spend the coin to change valves.

That’s the difference between EPA motors including the cam.

 

[Olde Man]

The big difference between the 585 and the 600 is the longer duration in the intake timing. If you do not deck the heads to raise the compression to make up for the late closing of the intake you will loose a little bottom end using the 600.

 

[mittens]

So its not just the Cam swap but decking the heads and larger valves? which is not just changing a valve. it larger that's cutting new seats and all.

Or is it just decking the heads and the cam? how much are the heads decked?

 

[mittens]

Well got push rods loosened, rocker boxes off, & now want to pull heads BUT. My compression releases don't seem to unplug. So going to chase that & figure out what the best way to disconnect them, so I can pull heads & jugs & start cleaning. Open to ideas. My bike is old school hard wired. So looks like the compression releases wires go into back bone of frame & come out under seat. Then split. Blacks go strait to a ground lug on battery. Greens tie/ plug (about to do surgery & figure out what is under this heat shrink) into a single yellow wire that goes to the buss bar. That's it... open to ideas.

Also my springs are not what I expected they look like tripple set? S&S ran serial number & my 107 shipped with red stipe .640 springs. I had to look hard but can find some traces of red so assume this is them? I assume normal valve spring compressor tool will work, remove keepers, and then can drop valves out to clean them and replace valve seals like normal?

 

[mittens]

Update. Cut ground lug off and hot wires off under seat for compression releases. Pulled pull wires through the back bone as I removed compression release wires so I can pull them back later. Removed head, rubber mallet on jugs broke them loose. Removed them. Now have dirty pistons hanging out. Time to start cleaning. Still need to check cam, then clean.

 

[Jwooky]

So its not just the Cam swap but decking the heads and larger valves? which is not just changing a valve. it larger that's cutting new seats and all.

Or is it just decking the heads and the cam? how much are the heads decked?

Larger valves need larger seats too.

@john sachs is best to describe the process and amounts. He did all my work.

 

[pknowles]

Update. Cut ground lug off and hot wires off under seat for compression releases. Pulled pull wires through the back bone as I removed compression release wires so I can pull them back later. Removed head, rubber mallet on jugs broke them loose. Removed them. Now have dirty pistons hanging out. Time to start cleaning. Still need to check cam, then clean. View attachment 120937View attachment 120938View attachment 120939

Might want to put some clean rags around the connecting rods. Don't want anything getting lost in there. Just a thought

 

[mittens]

Yea I put & keep tech whipes in the holes after pics. Probably can see them later. White & zero lint clean rags.
So got lifter blocks out, verified lifters are 33-5342 lifters, removed cam cover & cam. It is still the stock 520 EPA cam. So cleaning everything, & will be ordering a cam to suit. As always Curtis at WSW is to thank for answering my lack of v-twin knowledge questions from a gear head stand point. Have to remove the cam sensor first, then the Timing cup off the cam. If i had done this first the cam would have stayed in motor.... Live and learn. ha
So new cam, shim kit, & a lot of cleaning & polishing then assemble back.

I will be curious how much difference I can feel with a bigger cam. I have cam swapped every LS/LT I have owned, so fun to do the bike now.

 

[BryanPratt]

Sorry for the intrusion here but just wanted to ask a quick question. To wear while riding, are there any ready-made backpacks available with the water holder compartment? I was in touch with the Viking bags (https://www.vikingbags.com/collections/motorcycle-backpacks) and they said that they can make a custom one but they are charging too much for it plus the time. I'm not a very technical person and not really into doing it by myself, plus I have my camera gear in my backpack so I need something highly waterproof from the inside.

 

[Jwooky]

Sorry for the intrusion here but just wanted to ask a quick question. To wear while riding, are there any ready-made backpacks available with the water holder compartment? I was in touch with the Viking bags (https://www.vikingbags.com/collections/motorcycle-backpacks) and they said that they can make a custom one but they are charging too much for it plus the time. I'm not a very technical person and not really into doing it by myself, plus I have my camera gear in my backpack so I need something highly waterproof from the inside.

Random and irrelevant. Start a new post

 

[mittens]

So got a S&S .600 cam, .075 & .080 thrust washer, 2 cam cover gaskets that should deliver today. 0.070 washer was installed with old cam. Curtis was pretty sure about the .075 to be needed but got both to save time shipping in not. He said with the older 107s that came with the Bigger valves and red strpe springs the .600 works great, and was the factory cam. Sure decking the heads will make more but the .600 works great with this set up.
I plan to polish tapper blocks & cam cover real well, then once cam is installed, I will clean case/block of motor with wire brush & cleaner just to help it not be so dingy. Did it a little as a test and helps.

While waiting on cam, I started on the jugs. Here is a before (just how they came off the bike) & an after some testing on methods, only on the front inside of one, incase I made it look worse. Kinda figuring out what worked & what was not worth it. Then a pic of how they both sit today waiting on some more Dremel sanding bits.
I started out with a drill & wire brush to clean the ruff cast as best as I could. Then using an air angle grinder/ drill with 3" round red scotch pad. This allows you to get most of the flats of the fins. It will take the ruff casting marks/bumps & sand them off so you have clean smoother aluminum. Then I used black 400 grit Dremel wheel. They fit between the fins, & I can sit there sanding around each fin pretty easy & relatively quickly. The pic of the matching pair is only to that step. Tomorrow comes 600-800-1000 grit bits.
So I plan to do around of each. Then a round of polishing with Dremel polishing wheels or a big buffer wheel I have too that worked on the test peace. Should make the motor pop a lot better than before. I attached a closer up pic of motor with the dirty stock castings for
comparison.

 

[mittens]

One more just cause. Here is one done with scotch, & 400 grit only. & one strait off bike.
Once the other rounds of sanding & then polishing should be a drastic difference. I know I tried polishing after just scotch. It was better, then did 400 & polish & can tell that for sure. Then I used some 1000 paper just in the outside of the fins for a test & hit with polish & they came alive... that's when I ordered the multi grit bit set. So I can sand it all to that level before polish. But even here I think my work is worth it and that's not even polished.

 

[Jwooky]

Curious, if you are just replacing the cam why remove the jugs?

Conversely, why not deck since you are them off? It would be cheap at this point.

 

[mittens]

I removed the Jugs because the whole reason I took bike apart was to replace head gaskets and base gaskets. And plan to clean the motor up good.

How cheap to deck heads? Ruffly? Also how much do I need to have them decked? Not sure I can get into a machine shop quickly but worth a call or 2 I guess. I already have the big valves and springs. I do know, I still want the bike reliable and on 93 octane.

 

[HMAN]

 

[mittens]

Yes there was another thread on using the Oscillating tool, I have tried that too. This only works on the Slick parts of the heads/jugs. It does work well on the smooth areas, like the areas in the videos around the spark plugs, and stuff. as those came polished/smooth already. BUT the ruff cast does not just polish.

I have sanded the FINS inside tops and bottoms, and then will be polishing them using both the oscillating tool, and wheels. But the ruff cast does not polish, you have to get them smooth first if you want the whole thing to be shiny.

You can also hand Dimond cut them... with a Dremel tool as well. But don't think I am going to go down that path too. I would not mind trying it but not sure I want to jump into it on this set.