Category Archives: MegaSquirt EFI

Exhaust Looks Great, Fuel Tank Does Not

The exhaust is installed, albeit temporarily. It looks great! It mounts low and does not obscure all those pretty purple and chrome bits on the engine. :) I hope, however, that the baja bumper clears it.

It’s temporarily mounted because I wanted to verify fit and take a couple of pictures. I’m very pleased with how it’s looking. As for the exhaust, before it is permanently installed, I need to strip to factory paint off it. The paint on it is plain ol’ paint intended to keep it from rusting on the boat. It is *not* high heat paint. While it’s bare, I will install the oxygen sensor bung, then repaint it with high heat paint. It’s too bad there doesn’t appear to be a purple high heat paint, at least none that I’ve found.

I also finished a few other things that were pending, like completing the installation of the alternator and putting the belt on.

While all that was going on, I set the fuel tank on a stand and put about an inch of gasoline in the bottom of it. It did not immediately appear to be leaking, but once I’d gone on and forgotten about it, I came back to see a fairly large puddle on the floor under it. :(

The entire bottom of the tank was wet, so I couldn’t really tell where it was coming from.

I used/tested the fuel pump to empty the tank and another day, I will lightly pressurize it with air and find the leak(s) with soap bubbles. Maybe I’ll be lucky and it will be around the pump, needing only a better gasket to fix. We’ll see.

I’m Exhausted…

Or, will be soon…

Friday, I went to The Bug Stop and picked up a couple of things, most importantly an exhaust system. It’s an EMPI 3647, which is basically a 4 into 1 with a single muffler that exits to one side. There is a very slight “concern” that the included muffler may be too quiet, but that’s a pretty minor concern. :)

The weekend was far too busy to allow any trike time, but this week may offer some opportunities.

Prepare to be shocked…

The tank is finished!

I stopped at the hardware store and bought both oxygen cylinders they had. Ran them both out, too, though when the second ran out I was only reflowing some of the brazed joints for appearance’s sake.

It’s not my most beautiful brazing job, but I’m confident it won’t leak. Between the cylinders running out and me pausing to fetch fresh rods, etc, the bronze flowed a little wild in places, but it’s functional and will be covered in paint, anyway :)

I had to drill out the fuel pump mounting holes to account for slightly misaligned mounting bolts, but it didn’t take much to mount the pump. I even verified that it spins!

I wire brushed the filler spout, drilled out the mounting holes, cut a gasket and bolted it in place. In pressurizing the tank with a little air, the only leak I can detect is around the filler spout. It is cast from aluminum the sealing surface isn’t really flat. I worked it over with a file and it’s much better, but still leaks a little air. I will apply a little gasket sealant and that should take care of that.

I put a valve and a very short hose on the old fuel tank outlet and will use it as a drain.

All that’s left is to sand, paint and install it.

Oxygen everywhere but in the bottle

Man, I’m getting tired of running out of oxygen with my little Bernzomatic torch pretty much any time I start a project. I have a real torch and a couple of rusty old bottles. I need to see if I can get them filled and get/build a cart for the cylinders. Until then….

The fill spout on the tank is currently an aluminum flange that was “sealed” with PC7 or Bondo or some such applied inappropriately and secured with 4 sheet metal screws, which obviously leaked. While I want to someday replace it with a nice remote filler, for now I just want to fix this one. To that end, while the bottom was still open, I drilled out the sheet metal screw holes and brazed four 5mm bolts from the inside, providing both a strong method of attaching the spout and a reliable seal. I will need to clean off the sealing surface of the spout, drill out the mounting holes and cut a gasket for it.

Once I was done with the spout bolts, I cleaned the interior surfaces of the tank with WD40 and steel wool and wiped it out. It looks much better and hopefully the layer of WD40 will minimize the formation of new surface rust before I fill it up.

I wanted to put the bottom in from inside so that the remaining rim from the cut out bottom will serve as a strong bond so that the brazed seam will not be under a lot of mechanical stress. I trimmed the bottom for a snug fit. Starting with the end closest to the fuel pump opening, I used a deep C-clamp to secure the corner and tacked it in with a small bead of bronze.

As eluded to earlier, I ran out of oxygen after getting about 6 inches of either side of the first corner. I tried to use the MAPP gas with an atmospheric torch to continue, but it just doesn’t get it hot enough, at least not something this big.

I still wanted to continue for a while, so I decided to tack weld the rest of the bottom. With clever application of the C-clamp, Vice-Grips and a pipe inserted through the filler hole, I was able to tack all the way around the rest of the bottom. If I was better at welding, I would prefer to weld around the whole thing, but historically, I have had trouble getting a seal with my welding :) In any case, it will be ready for brazing when I get more oxygen tomorrow.

Bottoms Up!

I cut out the old bottom of fuel tank and made a new one.

The new bottom has reinforcement inside the bottom of the tank. I made it from two strips of 2″ x 1/8″ mild steel. Each side has half the opening cut from it and is firmly stitch welded to 16ga sheet metal bottom. I welded the seam between the two places with them in place so that there would be a little extra penetration into the bottom. The welds were not pretty, but they appear to be solid. I think I had the wire speed slightly too slow, making it sputter a bit

I drilled and placed the bolts and welded the heads to the reinforcement plate then flowed solder around the bolts to seal them.

Remaining to be done is cleaning the inside of the tank of mostly light surface rust and installing the new bottom. I have not yet decided whether I will try to attach it from the inside of the tank, which will be stronger and arguably easier to seal, or the outside, which will probably be easier overall to do.

Fuel Tank Work Second Thoughts…

I tacked, welded and dressed a reinforcement ring for the fuel pump. I think I really should have used a thicker piece, but since I’ll probably have to replace the whole bottom of tank anyway, we’ll see if this will work.

Using friction from the gasket to hold the bolts, it was a pretty simple matter to bolt it in place.

Of course, now that I think about it, it’s going to leak like a sieve unless I seal around the bolt heads. Even then, it will leak around the bolts between the tank and the reinforcing ring because the ring is only welded on the outside edge. Besides, there are probably pinholes in that weld.

Soooo… I guess I wasted an evening. Except that I just needed to do something with my hands.

I think I will need to get a 3 inch holesaw and a piece of 1/8″ or 3/16″ plate slightly smaller than the bottom of the tank. Cut the hole, drill for the fuel pump bolts, braze them from the inside for studs, secure the plate physically to the tank with a few bolts and braze around outside edge to seal it.

Somewhere in there, I need clean all the rust chips out of the tank out, too.

Delay for EDIS, but work continues…

Drat.

Boost Engineering has essentially backordered the trigger wheel, citing a manufacturing problem that should be corrected shortly, hopefully by mid April. Since I don’t want to further delay running the engine, I will get it running with the 009 distributor and convert to EDIS later, though hopefully not much later!

In looking for something unrelated, I found a cache of missing parts, namely the bag-o-relays and relay sockets.

Once I get the fuel tank in order, I should be mere hours from trying to start the engine.

Fuel Tank Work

After the last part of the week was stolen from me for work and the weekend and Monday fell to a stomach virus, I was definitely ready to cut some metal.

I pulled the fuel tank off the frame and drained it. I’m wondering why I completely filled it way back when. Now I have a really full 5 gallon can full of iffy gas. That’s a lot of mowing.

I first pulled the filler neck off. I found, not entirely to my surprise, that it was held by four sheetmetal screws and “sealed” with what appears to be Bondo.

With the filler neck off, I could photograph inside the tank. It’s not a happy sight. The outside of the bottom is somewhat pitted as well. Since it’s only about 16ga steel, there’s not a lot of material to corrode away. The entire bottom, if not the whole tank, should be replaced.

While I am formulating plan B to replace the bottom plate (or the whole tank), I will continue with plan A.

I marked and cut the hole for the pump and test fit it. I also cut a trial gasket.

Its Always Something…

Well, ok, it’s not so bad as that…

I cut new intake gaskets, installed the new intake boots (minus the clamps; I have learned to wait until I’m sure I’m through for those), bolted on the end castings, installed the manifold and trimmed the adapter plate as required to clear the alternator. Then I found an unexpected problem.

The throttle body must be mounted so that the throttle cable faces rearward. Between the throttle bracket and subthrottle motor, it simply wont clear the doghouse facing it. The other way, however, the inlet to the fuel rail wont clear the doghouse. I’m not terribly excited about having a plastic part carrying gasoline at 43.5 PSI crunched up against a vibrating metal part.

All is not lost. It turns out that the fuel rail fitting is a separate part from the rail, secured with a rather heavy screw and sealed with an O-ring.

By removing this screw, rotating the fitting and clamping the fitting down with a new fabricated clamp, I can adjust it to clear. The rail can be installed with the fitting at either end. I tried a couple different ways and have thought of a couple more, so I haven’t decided exactly how I will configure it, but it shouldn’t be too big an issue.

Otherwise, the 99% final configuration looks pretty good!

A Small Dose of Disassembly and a Big Dose of Ignition

I pulled off the old manifold (and, of course, the alternator) from the engine last night and verified some of the fit requirements. While I was in the pulling mood, I also pulled the distributor. There was quite a bit of corrosion around the distributor shaft. I suspect there may have been blasting soda left on the surface that, once it got wet, dissolved the protective coat of oil. In any case, it took substantial effort to pull out the distributor, but there appears to be no permanent damage.

The case stud that the manifold normally mounts to was missing. I recall before discovering that the threads are pretty bad in that case half. I spent a few minutes chasing the threads with a tap and installed a stud which should arguably have been there all along.

I painted the new manifold to match the rest of the engine. Once the EDIS system is in place, I will paint the oil pump block plate and the distributor plug to match.

Speaking of distributor plug, after a brief search, I found an online source [Boost Engineering, since closed] for one, as well as a ready to use trigger wheel/crank pulley.

I have several stock pulleys and a DIY AutoTune trigger wheel.

My plan was to mount the trigger wheel to a stock pulley, with spacers to lift it out from the surface. Since the center hole of the trigger wheel is too small for the head of the bolt and I don’t currently have an appropriate way to enlarge it, I would need to make it removable for access the the crank pulley bolt. Furthermore, I would need to carefully place the wheel very close to the precise angle in relationship with TDC and allow for both radial and angular adjustment of the pickup.

Well, this pulley fixes all those problems at once. It’s not particularly cheap at $135, but it’s a far more elegant solution than what I could make at home. The trigger ring is continuously adjustable, leaving me to be concerned primarily with radial adjustment of the pickup. I’m basically trading dollars for convenience and work time.

Similarly, while I could definitely have someone turn a distributor plug for me or even do my own with my drill press, this one will be here in a couple of days and I’m not sure I could have one made for the same money.

BTW, Boost Engineering [since closed ] also sells complete kits of either MegaJolt ignition only systems or MegaSquirt systems with all the ignition components (no EFI parts). Since I had most of my system components already, I didn’t need the whole shebang, but it’s cool to see someone offering it.