Saturday, February 7, 2009

What, me Hurry?

Finishing the tank has been an interesting exercise in patience. The good news is, the sectioned-out piece was leakproof right off the bat -- it was filling in the old petcock holes that took 3 tries. Borrowing a bicycle pump, filling a sink with water, and sealing up the other holes resulted in a few pinholes, but with some patience and 3 attempts (and a switch back to "spit") determined all was sealed appropriately. Now that the bottom of the tank was airtight, I promptly drilled a hole to put in the repositioned fuel drain tube. Using lessons I learned when I modified the 916 tank to work with the SS engine, I was able to do it right the first time. Again, the fuel drain tube was plugged, and I forced 5 lbs of pressure into the tank. Some spit around the welds, and.... no bubbles! A trial fit on the frame showed a nice smooth path from the tank drain to the carb. Sorted!

Now that the major fabrication has been completed, it is down to the niggly things to finish. Scrimping here can really make the finished product look poor, so at all stages I am going to try to avoid the Home Depot alu strap (although I've said that before) and use steel nuts welded in, rather than the quick and easy alloy nutserts. The first detail job was a set of fork stops. Dave had tacked on two small, short tubes to the side of the frame, just aft of the steering tube, likely to mount a fairing stay to. It turns out that the fork tubes hit this area at full lock, so I cut some neoprene round stock to suit, drilled it out for an M6 bolt, and tacked in a shouldered m6 nut into the end of the short tubes. I now have a workable steering stop, adjustable even, if I want to re-cut another section of neoprene to a longer or shorter length.

I also finally got in the J-bend piece of 1.75 inch tubing from Canadian Tire, and started to route the exhaust towards the rear of the bike, skirting around the oil tank return hole, and the oil drain bolt. I also wanted it to point near a rear frame lug that I had welded a nut into, to act as an exhaust mount. Everthing is still tacked, not finished; will need the muffler in hand before I finish anything. Should get that from Pop next weekend.

The Tyga kit also came with a beautiful battery box out of aluminum, and it fits perfectly on the rear subframe, and under the rear seat hump. Nice. In my pile of parts I got with the engine, I also found the oil retun tank (not the actual oil tank), and it fits "OK" on the frame. Will have to sort the hoses, but it should be OK as is. Might fab something out of aluminum once I become a proficient mig welder... one less thing to buy.

I got my hands on a KTM-style headlight fairing from eBay.UK. Been looking for one for years. It wasn't cheap, but it will look better (I think) than the Tyga full fairing, and a lot less hassle to live with. Will post the Tyga front fairing and accessories on eBay shortly... as soon as the headlight fairing shows up. Seller seems like a good chap! Oh, and speaking of oil, I'm gambling that an oil tank from a Yamaha Raptor 700 will be suitable. I think it will fit just under the rad, in front of the engine. I will have to come up with some sort of mount for it, but the volume, according to my reaseach seems to be right. No more than the stock 2L, but at least no less.

I also got the staintune header back from Cycleboyz. My big worry was distortion -- any minor warpage at one end could have severe consequences at the other. It lined up perfectly! I was HUGELY impressed. There were four different areas to weld, all tacked and only a bit of fill to deal with, but it was absolutely BANG ON. Their welder is a genius!

I still need to paint the exhaust mount (which I built from 4130), but I really like the look of this system. The guys at the shop don't hold out a lot of hope that the welded sections will polish out. We'll see, but I might put a hi-heat coating on it (eventually), rather than wrap it again in header wrap.

I'm still not sure about that yet. I wonder what it will sound like, or how much farting around I'll have to do with jetting. Those wimps and their EFI bikes!

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