Cheap helicoil taps not worth the risk

I helicoiled the threads for the cam tower bolts to increase strength and prevent them from pulling out. On the last hole, the helicoil bound ever so slightly and broke the tip of the soft metal insert tool. I had a mangled pile of metal jammed deep into the head. Fun.

1 hour was spent with a pick, surgical pliers, and a tiny tiny flash light. Once I got the broken tool piece out of the way I bent the top portion of the helicoil into the center of the bore. Then I grabbed it with the pliers and slowly twisted it out.

I cleaned the rest of the metal out, followed the threads with the helicoil tap, and reinserted another helicoil with a quality insert tool.

Moral of the story: Dont skimp on helicoil tools.

 

Rock Flute: The engine work continues.

I've had to clean up a few fins after dropping the head on the ground. Flap disc; 100 grit and a 220 spit shine on the ends took care of the damage. The more fin you sand off the thicker they get. Theres a lot of meat in there so if you want to shine the ends of the fins, take the edge off with a flap disc and then smooth them out. Don't go nuts though. Afterall they're there to keep youre engine cool. 

I helicoiled the cam tower threads, checked all the guides, and added some rc aluminum retainers.  Unfortunately one helicoil bound for a split second and snapped the super cheap insert tool off in the hole. Ill be working on that later.

After the metal work was done the head got a bit of a chemical clean and coat of paint. It sat for about an hour and then I sanded the edges of the fins with 220 grit to remove the paint. Classy.

The cyls got scuffed, honed, cleaned, and repainted as well.  The old gaskets were of course a pain to remove.

F-model Rod Bolts

Tore into an old bottom end laying around the shop to start building an 836 for this spring (yeah I know it's already spring, that's why I gotta hurry).  Found something that'll save me 50 bucks and some time.  At one point in this engine's life someone who knew what they were doing was inside this engine.  I found that the crank has been cleaned before and allen screws installed to cap the oil passages.  I also found it was already running F-model rod bolts on K rods.  The original K bolts (seen on the left) were "torque to yield" and have to be thrown out when you remove the rods.  F bolts are reusable and also cheap insurance against the weak K bolts in the budget 836 I'm building.

Stronger cargo box for Rock Flute

I found some stainless tube I had left over from making oil lines and decided to use it to reinforce my chianti cargo box. My intention was to releave the force on the wood panels from any junk I put in the box while also providing a place to tie straps to.

I didn't spend much time doing this and formed the ends of the tube with a hammer and vice. Smoothed the metal and then heated the stainless to change the color to a bronze. Heat slowly and evenly to change stainless to the color you want. Then let it cool for a second to see what color will remain.

Next ill add an aluminum plate to the base so I can load this thing with weeks worth of crap like a minivan.

Rock flute has lost compression

Primarily number 4. Time to rip it apart, make some repairs and maybe some upgrades!

This engine was transplanted from Bat Vagina, my old long bike. Its all hopped up and ported... and stuff.

I tore it down and found two stripped cam tower bolts and some bad build up on the no. four piston. Thank the Lord almighty for the modified valve cover or the Yosh Daytona cam and its aggresive profile would have ripped this head apart.

Welding Stainless Steel 304L with 308L filler rod.

So...stainless.  First i will show you some welds and explain them.

1st.  looks like a good weld...but actually it isn't correct. Notice how grey the weld looks...that's running too hot...may get a decent weld, but wont pass a weld test. The heat lines should also be close to the weld like in pic 2.  Quick evidence of too much heat, that you can see while welding, where you cannot see the grey color while welding.

 













2nd. this is exactly what a good stainless weld looks like. some pinks and blues...NO GREY. this is correct heat.

Stainless needs to be back purged with argon. If you don't, then the chromium comes to the surface as chromium oxide and will lead to cracks (sometimes immediately visible) and ultimately a short weld life.  So if you do tubing, the tube needs to be taped shut and filled with a constant flow of argon through it. If you do this, then the inside of that weld will look exactly like the outside...if not then you get the Cr-oxide like this..

The funny thing about SS is that when you are having trouble...turn the heat (amps) DOWN....where as with regular steel you may want to go UP.

If you have access to a TIG machine with PULSE...USE IT.  It controls the amps in a square wave and sort of clips it...prevents excess heat going into the metal and causing the chromium to surface.  If you don't have pulse...then you strike an arc...make a pool, dab, then reduce the arc to almost nothing allowing the puddle to almost cool off...then move, and repeat. You cannot (easily) weld SS in a normal flowing line like with 1018....unless you are DEAD on with you heat and speed of travel, or use pulse...then you can weld it like butter.


You can polish off the colors after you are done and get a pristine weld like below.

BV is up on the Bay!

It was rebuilt in 2010, has a custom front end with internal brake lines, raked frame, widened swingarm and rear fender, new chrome bits, and an Acewell digital speedo with a slew of options.  This bike was designed and assembled with great care.  The front end is raked internally to drop the trail to 3".  It is adjustable to remove the internal rake, but the trail jumps to somewhere around 18 inches.  The engine is a late model 77/78 engine with new gaskets and a rebuilt ARD Engineering Magneto.  The round top carbs are super clean and the bike starts right up every time.  Chrome is in great shape, easily a 9 out of 10.  Only a few spots and nothing a little wax wont take care of.  The paint is in great shape as well.  Seat upholstery is perfect, tires have many many miles left on them, brake pads are in good shape, etc etc.  The exhaust is an old set of 1-4-2-3 crossovers with header wrap.  The sound of the pipes is incredible.  A lot of bass and an overall great sound all the way through to 10,000 rpm.  This bike is in great shape and is 100 % ready to ride.

This bike is a blast to ride and I'm really going to miss it.  There are so many things about it that go against what a typical long bike is.  3 inches of trail makes it carve nicely in the corners.  It's responsive and agile.  The 75* of free rotation in the front end give you a turning radius better than some new cruisers.  The magneto gives it both visual and audible character.  The twin discs up front allow you to use the front brake with confidence and no twist.

There are many things I'll miss:  Laying back and sliding around the corners.  Ripping the throttle wide open and watching the girder links rise up.  Pulling up next to cars that are shorter.  All of the questions like "how the hell do you ride that?".  It's a breeze.  Ride what you build and ride the piss out of it.

http://cgi.ebay.com/ebaymotors/261124384724?ru=http%3A%2F%2Fmotors.shop.ebay.com%3A80%2Fi.html%3F_nkw%3D261124384724%26_sacat%3D%26_dmpt%3DMotorcycles_Parts_Accessories%26_odkw%3D1972%2BCB750%2Bchopper%26_osacat%3D0%26bkBtn%3D%26_trksid%3Dp4506.m270.l1313%26_fvi%3D1&_rdc=1

I'll definitely miss the Ol' Bat Vagina.  Yep, that's the name. Enjoy.