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 sourceĀ [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.

Harness Wiring

It took most of the day, but I wired the throttle body and reconfigured my original MegaSquirt ECU harness.

For the throttle body, I took the shortest two connectors from Buzz’s old harness and remade them, connecting one injector to each output and running separate power leads. When I originally made the old harness, I was not really aware of the needed seals. It doesn’t do much good to have a weatherproof connector without sealing around the wires. So even though the throttle position sensor (TPS) cable was a suitable length, I needed to cut the pins off anyway, so I rewrapped it in yellow heatshrink while I was at it. Astute observers will see an extra cable in the bundle, the one with the white connector. This is the currently unused factory subthrottle position sensor. It costs nothing to leave it there, just in case someone someday writes subthrottle support into MegaSquirt :)

On Buzz’s harness, the intake air temp (IAT) wiring was sort of an afterthought, so while the sensor was on the throttle body, it was connected through the frame harness. This time, it’s right there with the other throttle body connectors. Also, the old IAT and coolant temperature (CLT) were wired to the ECU in a 3 pin connector that shared grounds because those sensors both came in from the frame harness. In this case, one is on the TB harness and the other will be on the engine harness, so they will each have a two pin connector.

New to this lineup is the wiring for the idle air control (IAC) stepper motor. This was one of the modifications needed inside the shell, adding four wires. The pins are essentially randomly connected to the motor itself. Unless I was just EXTREMELY lucky, I will need to rearrange the pins before I can expect the motor to work.

While I had the DB37 shell open, I also made the injector leads into single 14ga wires instead of doubled 18ga.

As for the harness, it’s mostly like it was, except nicer. Some groups of wires are bundled together with expandable sleeving and all connectors have been remade with seals. Finally, connectors were added for the options applicable to this job that weren’t on Buzz, like the EDIS ignition system and a permanently connected wideband exhaust oxygen sensor.

In the old system, the wire labeling was very clear until the wires were handled. Wherever possible, I have relabeled the wires using white heatshrink tubing, written on with fine point Sharpie then covered with clear heatshrink. As I re-redo a couple of the connectors, I will relabel the lines I missed.

More Intake Progress

I have the throttle body adapted to the manifold in what I presume is very nearly final form.

The 95% completed adapter plate is the key to making this very nearly a bolt on conversion.

Sharp observers will see that I drilled the two inside holes incorrectly the first time. I had my template placed wrong. Luckily, there was still plenty of metal to thread into, though running the tap though was tricky. I had to run it forward all the way through and pull the shank of the tap though the back side of the hole. Attempting to turn it out backward made the tap cam into the erroneous hole and jam.

To truly finish the plate, I need to weld on a brace fro the throttle body, media blast the entire assembly and paint it with something fuel-proof, probably epoxy.

As a side note especially for anyone wanting to use this throttle body, get the stock mounting boots and O-rings. In my opinion, scratch fabricating something to fit is just not worth the effort. They are about $20 apiece from Kawasaki [part no 16065-0024]; I paid $20 for the pair on eBay. One online Kawasaki parts house sells the O-ring for $4.71 each, but I found an excellent equivalent O-ring at AutoZone for $0.99 each, FelPro part number 35087. It happens to be for the water outlet for a 91-95 Saturn 1.9L. Beware, however, my AutoZones tend to stock only one per store, so I had to go to two stores.

As for the rest of the intake manifold assembly, I have not placed it on the trike yet, but I have mocked it up in the level mounting position to see what the angle of the all components will be. As luck would have it, the rearward angle of the manifold and the rearward angle of mounting boots are the same, or at least close enough that I can’t tell. It remains to be seen whether I will have the throttle bodies mounted as shown or flipped around so the throttle cable approaches from the front.

Intake progress

Everything came together to give me a couple hours’ time to work on the intake.

As mentioned earlier, my pretty adapter plate was cut before I knew I would be using the stock Kawasaki boots to mount the throttle body. Because of the way the boots bolt on, there is some degree of overhang.

I welded mounting tabs on the plate, drilled and tapped holes for the boots and drilled holes to mount the plate to the manifold. Sadly, my drill creeped a little, so one of the mounting holes doesn’t line up perfectly. It will be easy to address and will not be visible once installed. Oh, well. Such is the way of hand fabrication.

Other than that, it looks pretty good.

Once I have the manifold installed on the engine, I will have some experimental freedom on positioning the TB. The boots impart a small angle, which leans the TB assembly, and the TB itself can be mounted to the boots with the throttle eccentric on either side of the engine. I don’t think it will clear the doghouse if they lean forward, so I’m sure I’ll need to angle them backward. Then it should just be a matter of choosing which side I need the throttle cable to come in.

Buzz Robbed

Well, it took about an hour to remove all but three small traces of the EFI project from Buzz. What’s left is the CLT sensor, securely JB Welded to the cylinder head, the FIDLE LED and the O2 sensor bung, plugged with a sparkplug.

The airbox was as much fun to put in as it was to remove. :)

I began cleaning the stock carburetors late this afternoon. By the time I was tired enough to not want to start another, I’d cleaned three of them. The last one has been completely disassembled and the solvent-safe parts are soaking in Berryman’s Chem-Dip.

Between the Chem-Dip and just judicious cleaning, they look pretty close to new.

Buzz will need a plug for where the O2 sensor was removed, the fuel petcock reinstalled in the tank, the carburetors reinstalled and a battery to be ready to start. After that, a thorough and serious cleaning is in order and he’ll be ready to ride or sell.

If I keep Buzz, I will eventually go back to EFI, but I know now that I will need to use a smaller throttle body and will probably need to built a custom intake manifold. It would probably make more sense to procure a bigger bike and ‘squirt that instead.

Clearing The Cobwebs

After the holidays, the recovery from the holidays, a busy travelling February at work and a bit damage from actual winter here in Texas, I think I can finally get this show rolling again.

I’ve decided that amongst the first things to do is to restore Buzz to stock form, salvaging all the EFI components that I now need for the Dragon trike, especially the O2 sensor. I’ve already robbed the ECU…

I’m still contemplating selling Buzz. I could use the space and the funds, but we’ll see.

Here is a list of several big steps before I’m ready to start wiring the engine and ECU:

1: Put the fuel pump (and fuel gauge sender?) in the tank
2: Drill and tap the adapter plate for the throttle body
3: Install the new manifold to the engine
4: Attach the trigger wheel to the crank pulley
5: Mount trigger wheel sensor; will probably require some sort of mounting bracket

By that point, I’ll be very close to ready to crank the engine.