h4nd's 1974 Daihatsu Fellow Max 360

[h4nd]

Left the interior lamp on. Oops.

Worth a crack. Yeah. Nah.

[h4nd]

Oops

 

Oh there's why. Who the bloody hell mounts the terminal in the flappy area of the alternator belt !!1!1

... oh, me.

[h4nd]

Anyway, routine maintenance:

 

[h4nd]

Oh - it was starting to run shit because of ... plugs!

Who'd a thunk?

I should really put the good motor back in.

[h4nd]

Oops: this was getting substantially loud

British tech to the rescue (temporarily)

Whilst Hamish at Hammer and weld did this to the other one:

 

[h4nd]

That was all before x-mas mind. I got the repaired expansion chamber / muffler back, then split the motor from the gearbox about a month and a half ago, but the bus run to new work is so quick, I got lazy...

While the motor and box have parted company, I thought I really ought to investigate the grindy clutch noise:

It feels fiiiiine, so I guess I'll go find a 2nd opinion? (i.e. procrastinate putting it back together again)

[h4nd]

[h4nd]

@ajg193 was kind enough to chat mech, and pointed out that the gearbox doesn't spin when the clutch is depressed, so the rumble is probably the motor output. Of the shit motor I want to change out.

I should'a just gone with my first instinct and slapped it together and sent it.

[h4nd]

Mods are asleep! Shitpost in your build thread!

I realised that part of what I like about working on the car, is wombling around in the shed listening to Concert FM (YMMV).

This went west when I vacated my work office, but now I have have those dulcet tones back.

Let's see if it helps

[h4nd]

So I had a pretty good set of gaskets, courtesy of @kyteler, which fitted nicely except for the carb one:

Sooo, down to Repco! 

/s

Generic gasket: some assembly required

Then bung the motor in the hole, line up the stick thingy with the hole thingy

I have some new tricks to make this a one-man job: 

drop the engine mount off the motor rear-left; also remove the fuel filter and bracket from that corner,

Suspend the motor with a ratchet strap, TWO pinch bars:

Once you get the first bolt from motor to box in, ye can squeeze the rest together with any old G-clamp.

1/4 inch socket set doing the good work to get the bolts back in that left-rear engine mount.

Now it just needs fuel, oil, spark and starter hooked up for the traditional piss the neighbours off  test.

It'll be a few more days to get it roadable (Alt, cooling etc), but mostly this (these):

Yar, those won't buff out.

Well, off to see Hamish at Hammer-n-Weld, he's a nice chap anyways.

[h4nd]

... and he did it the next day, Nice!

so today, onward:

 

17 minutes ago, h4nd said:

Maaan, car electronics are so complicated.

The wires carrying the sparks have to connect all the time.

Except if you nudge the metal case of the regulator relay - that's the wrong kind of sparks

Once you get the sparks jumping up the wire, the car is still fussy, you have to get each of them to their own cylinders, at the right time and everything.

Anyhow, that means it cranked for a while without catching and running. and that's perhaps given me an important warning clue:

Yeah, there's only oily goo coming out one side. These engines pump 2T oil to the main bearings, which then lose it to the crankcase, so it looks like #1 may not be getting the good oil

 

[h4nd]

Yeah, bench tests the same, no juice one side.

Maybe it's run dry from being disassembled a few months.

I looked at the manual, and looked around online: Consensus is that they're a very reliable part with a long lifetime. Lots of motors use variants of this Mikuni device.

A snowmobile guy had a good example of bleeding the pump, but alas, that screw isn't on my pumps: https://www.youtube.com/watch?v=Xde96VD8-fY

This is similar, and shows that they can be rebuilt if needed, but again, has the bleed screw I don't  https://www.youtube.com/shorts/Js4hz74jB1g

I do wonder if that was a later addition to the part. I grabbed another pump from my stash, and it wasn't pumping at all. I tried blowing the 2T oil down the tube, but that wasn't priming up up either. 

The answer seems to be simply to loosen the two screws on the plate and wait for air bubbles / oil at the top, then tighten. The 2nd pump is now working, I'll try the other one again soon, just to check that method works on both.

Re-assembly ahoy. Then I can change that carpet...

https://photos.app.goo.gl/NigkK3wQnPRRXHom8

[h4nd]

The 2nd pump from the crap engine I've been running for a while was working, but it had some grey paste in the shaft that I didn't like the look of.

So I went back to the 1st pump from the good engine bench tested, and yep, that seems to be the way to bleed it.

So I fitted that up to the engine and did a couple of crank sessions.

Nope, I had to bleed it again in situ (twice) to get it to prime up. which it did.

So, a quick test run. 8s of 2T fury!

[h4nd]

It'd start and run briefly on ether, but it became clear that it wasn't getting fuel.

I fitted clear tube to the fuel line and did the suck test (have had mouthfuls of fuel before, do not want) and fuels coming up OK. Suck!

I've pulled the fuel pump and spare, (multiple times - and that pretty fiddly because every 2nd bolt / nut on this thing is nearly blind under some other tiny carb/dizzy etc, LoL),

• it does seem that the air pulse from the crankcase is getting up the manifold casting (oily rag over the hole blew off enthusiastically)
• Have split the pump from the good motor, all looks clean and well.
• 
• diagnostic test from the manual is to suck on the fuel outlet line - seems ok,
  • blowing into the inlet it gently seems to release the pressure relief valve OK.
  • (sprung thing on the right releases fuel back to the first chamber
  • the copper bit seems to belong on the face of the pressure relief valve?)
• The gasket on the manifold is looking a bit crap.
  • I didn't think to put soapy water on that when I was testing, so I'll make a new gasket for there, and test with soapy next.

I'll also split the old pump, because I think its diaphragm might be leaking, and just to get a look at the condition of it.

All in all, as EpochNZ says, it seems to be fighting a bit this time.

Sitting for a while seems to be bad for cars, best to daily them, I think.

[h4nd]

Yep. Found and fixed a couple more faults. Diaphragm.

I'd tried the good local parts suppliers, and the old car afficionados, and some bike shops. Nada.

As with any old/rare car, sometimes part of the difficulty is finding out what the parts actually are. The MIC marking says its a Mikuni pump, but which one?

My workshop manual just says "Fuel Pump: Diaphragm type". Great.

I traipsed all over the internet, and wasn't getting hits on the old shape ones (plenty of new ones in Rotax, Polaris etc, but they don't have the 1-2 PSI pressure release valve: so would drown the carb bowls, and flood it and - foul the plugs. (Why do 8/10 faults in 2T foul the plugs? The others burn the piston, or turn them into parts that sound like broken crockery)).

It was starting to get a bit surreal:

           

              Riiiiiight. Very helpful.

I found a Diaphragm in .eu, but, Fronch, and red: Merde!

I'd also have to modify it for vacuum, and to retain the other spring. Merci, mais, non!

I remembered my fav rare Kei car parts supply, and just happened to notice a pic in the "Latest News" corner:

None in stock, but a link to a page about them:  https://www-irex--jp-com.translate.goog/catalog/product_info.php?products_id=3206&PHPSESSID=0fc980561a64a1ece75e17e24c523f47&_x_tr_sl=ja&_x_tr_tl=en&_x_tr_hl=en&_x_tr_sch=http

Which led to this subaru parts list, https://www.mysubaru360.com/manuals_and_documents/Subaru_360_parts_prices.pdf

and thence to this:

Now finally, I have a part number to cross reference, and away we go...

Off to ebay: https://suzukioutboardmarine.com/product/15100-7281v-two-stroke-fuel-pump-diaphragm/

Of course! old 2T outboards need to pump the fuel up off the floor of your Tinny.  Then to find local dealer.

Closest boat shop is Yamaha, they have their own brand fuel pumps, but next one along...

Boom. New Kei car parts supplier on tap.

I may have sharned the owner a bit, but he seemed pleased to have a new customer (in another 50 years, when this fails, I guess).

Not perfect, but a probable fix.

Onward.

[h4nd]

..but no. After starting it a few times on ether, it's still not pumping right. 

I had a good look at a spare, and this one, and thought I'd put good enough parts in it. At one point, it would pump up off the floor, but just now, it will pulse twice, draw up ~1cm, then stop.

(parts cleaned, inspected, then discarded):

 

So remembering a comment from someone about the simplicity of gravity feed from a bike, I just put a wee 1L tank on the scuttle, and tried again. Now with a good temporary fuel supply, it's become clear that there's still problems. I'll come back to the fuel pump later.

 

It's spitting lots of fuel out the top of the carb, much like when I changed the motor, then discovered that the exhaust was just blocked with carbon. The front end of the exhaust has been rebuilt, but I still checked it by splitting the just re-assembled system, and passing air from the middle forward, up the exhaust ports, and out the spark plug hole.

Then I put the hot air gun into the muffler, passing air backwards. After 5 min, it started making vile smoke that smelled like cancer, and even some amusing pulse rocket noises. Good enough. 

 

[h4nd]

So it's time to dive back into the carb. On second examination, there were a few faults, (as mentioned in spam):

• emulsion tubes gunked,
  • so idle mix setting was wound miles out to compensate (8T, manual suggests 2),
• pump plunger leather collar was twisted (though it still seemed to be working ok)
• and a hole in the back of a carb punched out from someone using a too long screw (maybe/probably not me).

I stripped, it, checked stuff, cleaned the gunked emul tube, etc, and tested.

At first glance the fuel level looked ok, and it was shutting off fuel from the wee header tank OK (I had put some clear tube here, just for diagnosing this),

I had a read online of various diagnosing steps online, and fuel level was a common suggestion for this fault;

but here was the kicker:

• float valve badly worn
• float valve pin holder posts slogged
• float valve clevis holes slogged

each of which would have raised  the fuel level in the carb.

So combined, fuel level rather too high:

 

So I got the better parts from the other carb, guessed a better float level, and threw it back in.

Presto, the fuel haze above the carb is gone, and it'll start and idle without ether, and with just a bit of choke.

[h4nd]

Naturally, I give a moment to warm up, then give it some boot, to see how it revs:

Nope.

I'd just re-checked the ignition and timing, so was reasonably confident that was OK, and I seemed to have the carb in better shape:

(I've just realied as I type, it's possible I've lowered the fuel level too much, and it's leaning out under throttle. If so, that's dangerous for 2T, they overheat and destroy top ends really fast, but see also:)

I left it for a day and had a think, tried again, and noticed this:

This was 10-20s after I stopped it. That seems to be exhaust smoke in under the carb. I blew at it, and it looked like smoke, it's not fuel vapour.

This implies the reed valves aren't right. 

 

Before I changed the motor (to the not-rebuilt one) a couple of years ago, I spent quite some time on the reed valves, as it seemed to explain the symptoms at that time. However, that was a year or two of daily running ago, on (inspected / fettled) 2nd hand parts, so maybe they've just aged out, cracked, chipped, whatever.  It's incredible how many times those steel valve petals must have flapped over the years, really.

So I'll have a look at those next (another surgeons job to remove, not much hand space down the back of the motor).

Should they look terrible; once upon a time one of our scooter suppler chaps ( @Mop Head?) sent me some carbon fibre sheets, so I might even be able to cobble up a 'performance parts' replacement even better the OG factory.

 

Tho, first I'll see if I can test them in-situ. so I built yet another pneumatic test-jig. This one might let me seal to the top of the carb, and the vacuum side of the mattess pump should pull the reeds closed. 

I'll test the tester, and see if it can detect the pressure difference from stoppage to a small leak.