h4nd Posted December 11, 2014 Author Share Posted December 11, 2014 Have just had a chat with the engine builder. Toy should be ready tomorrow. Radiator has gone missing in the meantime, so I'll throw my spare at it, and chase up later. :) 4 Quote Link to comment Share on other sites More sharing options...
Popular Post h4nd Posted December 11, 2014 Author Popular Post Share Posted December 11, 2014 26 Quote Link to comment Share on other sites More sharing options...
Popular Post h4nd Posted January 3, 2015 Author Popular Post Share Posted January 3, 2015 17 Quote Link to comment Share on other sites More sharing options...
h4nd Posted January 4, 2015 Author Share Posted January 4, 2015 NZ post computers had forgotten that 40 year old cars don't need continuous licensing, so I spent 25 minutes on the phone to LTSA, who did remote "maintenance" on the counter I was standing at, so, cheap old car license is mine! That saved enough money for a coffee, but the engine has a bit of a hesitation which is trying to spill coffee in my lap. I think I've got that sorted on the drive to work. And wow, I need to vacuum the car / change the carpet. (Engineering solutions R us). Bonus points if you can work out what radio station I'm rocking on the AM. 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted January 16, 2015 Author Share Posted January 16, 2015 It's the little things that count. I had a little time, so I thought I'd get out and have a look at the ignition. While I was in there, I noticed the new engine / cooling system is leaking coolant. In behind the grille, behind the manifold / expansion chamber, behind the first waterpump hose, is the second waterpump hose. On that is the hose clip, which was approximately finger tight. Owning one of these cars makes a person appreciate a good 1/4" socket set. Other loose hose clips were located and snugged up. 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted January 17, 2015 Author Share Posted January 17, 2015 OS BMW repairer Bart needed some electrons donated. I thought the Dai would work OK, cause the regulater has crept up to ~14.7V, but it wasn't happening in the 10 minutes we tried. Oh well, onwards. Better leads required? 2 Quote Link to comment Share on other sites More sharing options...
h4nd Posted January 22, 2015 Author Share Posted January 22, 2015 The 360 need a tuneup, 'cause my buttometer was telling me it was 5-10hp in arrears. I happened to have access to a portable oscilloscope, so here's the results from last weekend Here's the -ve terminal of the ignition coil. It's a 4 lobe cam, so 4.5 divisions x 5ms x 4 lobes = 90ms per rev. 1/ 0.090 = 11.1 rev / s * 60s/min = 666rpm at idle. Problem is that the points are closed for ~12.5 ms / 22.5ms, thus ~55%, thus 55/100 * 90 degrees = 49.5 degrees. Dwell angle is supposed to be 47 degrees (Working from memory, will check later). This is the same adjustment, but revving faster. The timebase of the scope has been set to 2ms, and you can see the 'ringing' AC as the energy sloshes from the inductance in the coil to the capacitor on the points when the points open. I got in there with a feeler gauge, and the gap was around 0.25mm. You can't see the top of the waveform in these pics, but the peak voltage is 150 - 200V (yep, on the Low Tension side) and gets multiplied by the coil / transformer ratio for the HT side, thus 150V x100 = ~15kV. Usual insulation gaps are around 1kV / mm, so thats getting a bit iffy. The manual for the engine says 0.3mm - 0.5mm gap. I polished the faces of the points to get them square (they form points and dips because of ion material transfer), and set to a shade over 0.3mm. This gave the waveforms below. Basically, you can see they're low (closed, i.e. dwell angle) a shade over 1/2 the time, and now meet the spec. A little grease on the dizzy cam lobes for good luck (it was dry), and then on to timing. Because I can turn over the engine by hand, I put a rod on the piston, and checked that the timing mark on the crank pulley was correct. Then I turned on the ignition, and rocked the engine to see where the points opened. This was easy, a nice satisfying snap from the HT as they do (don't run your HT open, kids, the V's can get too high. I had plugs fitted.) The ignition had been about 8mm too advanced (I'll work out that timing sometime later) and when set to factory spec, the machine was transformed. It now starts easier, a bad hesitation in mid-range is gone, and it revs out in the 50-60mph range much cleaner. Detail. It's all in attention to detail. 7 Quote Link to comment Share on other sites More sharing options...
h4nd Posted January 22, 2015 Author Share Posted January 22, 2015 Then, today on the drive to work, there's a "Toing!" noise, and a high pitched "zzzz" that alters with engine revs. I've had a look in the top, and plug #1 contained this: It's about 2mm x 1mm x 1mm, and gets picked up by a magnet. Engine builder has requested I not drive it, and bring it to him... I'm really not optimistic about this. Quote Link to comment Share on other sites More sharing options...
h4nd Posted February 27, 2015 Author Share Posted February 27, 2015 Right. The chrome (top) ring failed, but the locating pin was still there. Builder said he'd done the usual exhaust port radius, about 0.2 - 0.3mm. At his workshop, I showed him an original bore jetski motor with ~0.7 - 0.8mm chamfer at 45 degrees. Then I sent him an excerpt from Gordon Jennings excellent "Two stroke tuners handbook" Yeah, 0.4mm minimum recommended, and 2mm high on the 10 degree chamfer, which is a large change in port timing. No wonder it was down on power. I happened to have a appropriate sized piston in my stash, which measured up OK (not barrel shaped), was crack tested and fitted. He's re-shaped the ports, rebuilt it, and apart from a minor issue of a top mount / water feed cracking (replaced), it's running again. It's much crisper, and pulls through 60mph much better. Best yet, he's standing by his work, and not charging for this work. Kudos. It's been a blast tootling around in it, and true to 2T form, my hands have been grimy 4 times in the first day having it back. 8 Quote Link to comment Share on other sites More sharing options...
h4nd Posted November 13, 2015 Author Share Posted November 13, 2015 9 months later. There's been moving, Nats in Coromandel, but mostly just dailying the shit out of this baby. I drove it to Hamner meet, and it crated Bigfoot back shotgun like a charm. It's still a shade down on hp. On discussions with Goat, he's suggested it's the labyrinth seal between the crank spaces (the only one I couldn't replace) may be weak. This isn't a major, and may even help protect the engine from over-revving damage, but time will tell. I now have a better workshop, and may pull it down to eyeball the exhaust port shape, per above. There's a few other maintenance items creeping in. The front shock / alignment needs attention, it's steers a bit like your grand-mother's tea-trolley, but it's running well enough to be fun commuting. And, a fine chap sold me a motor, after seeing it at the McLeans Island swap meet. More spares to strip/clean/sort! I may have 2 complete spare motors now (which starts the imagination on alternative uses). 3 Quote Link to comment Share on other sites More sharing options...
Popular Post h4nd Posted December 27, 2017 Author Popular Post Share Posted December 27, 2017 Sumner pipe cleaner. 14 Quote Link to comment Share on other sites More sharing options...
h4nd Posted September 27, 2018 Author Share Posted September 27, 2018 Car has been missing slightly the last couple of days. So I'm gonna drive it home to look for my spares... 1 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted February 6, 2019 Author Share Posted February 6, 2019 ^ I did, and fitted an old one. It's been OK, though a little prone to fouling #2 on the very old points I have. I'll have a looksy at the points cam consistency with a dial gauge sometime, before I change points. (2 months later): Rinnnggginging <TOINK> brrrzzzzzzzzzzz. Uh oh. That don't sound right. It's running, but I'll bet a lamington it's taken a ring end again. I'll tear down in the weekend and assess...' I may be lime scooting tomorrow. Arai and hi-viz? 2 Quote Link to comment Share on other sites More sharing options...
h4nd Posted February 18, 2019 Author Share Posted February 18, 2019 So, you know, check the spares: Most like that. Okaaaay. I'm rather suspicious of the port edge chamfering of the port done by local rebuilders for this collection from various engines. I'm ordering a couple of sets of gaskets (won't need the second set, right?), and will rebuild with a 0.25mm o/s piston and barrel I have. Interestingly, I've found a working translator for Yahoo auctions Japan, and there's a set of 1.25mm o/s pistons there. Next time, maybe. http://yahoo.aleado.com/lot?auctionID=d159583232 6 Quote Link to comment Share on other sites More sharing options...
Popular Post h4nd Posted March 22, 2019 Author Popular Post Share Posted March 22, 2019 Engine crane. 17 1 8 Quote Link to comment Share on other sites More sharing options...
h4nd Posted April 3, 2019 Author Share Posted April 3, 2019 Rinse, repeat. Photo album (and a couple of vids). https://photos.app.goo.gl/LH9moaASkxJuNtV8A 3 Quote Link to comment Share on other sites More sharing options...
h4nd Posted July 18, 2019 Author Share Posted July 18, 2019 So I got it going last time, and it seemed good for a couple of months. Then per this post over in the two-stroke tuning thread: I stopped at friends, dropped a thing off, then when I went to go, car start OK, runs OKish at idle but very much won't rev. I've checked the ignition, both sides look stable and consistent. I discovered that there's a bunch of fuel mist above the main jet on open throttle and especially as the revs come up. This wasn't there when it was running well (I have video for comparison.). I'd assumed reed valves, and a couple were weak-ish, but none broken, chipped or very much warped. Seats look OK-ish. I thought it may have been the fuel pump diaphram, but changed it: no improvement. On thinking about it again, I was unclear that would even blow fuel/air up the fuel line to the carb, the float valve should contained it. I've pulled down the inlet tract 4 times, with compilations of reed valves from old parts (best available, then older complete assemblies as cross check) but same symptoms each time. I happened to have another carb, and have thrown that on, same results. Is (stainless) reed valve failure really subtle? I'm looking at them, and they all look pretty good, just subtle differences in how they seat, and a couple which go "toing" (lower pitch) compared to most which go "ting". Pics, and running OK vs carb spitting vids: https://photos.app.goo.gl/vkXBbT8YS1p46RBC8 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted July 18, 2019 Author Share Posted July 18, 2019 The reed valves seemed OK, so I was scratching my head, (even ordered some carbon fibre sheet to make new ones) and then this happened: Quote A parcel landed by mistake in the office entry today, so I rang the guy to tell him. It was the guy who rebuilt my engine bottom end. We then had a yack about the Dai, (changed reeds, fuel pump, carbs) and he's like yeah, could be seal between the crank cases (the ONE part which couldn't be done at the rebuild). He reckons it may be leaking across from the other cyl and blowing past the other reeds on the other sides which haev just opened on their inlet stroke. (Says he's heard of it happening). That would be a pisser, though I do have a short block in good condition (and 1 in terrible state, and one in pieces). This may mean the Dai gets moved on after I've rebuilt it, I can't afford the time, lately. So I started pulling it down today. Even with a powerplant the size of a big family box of weetbix, it still looks like I'll have to pull the engine and transaxle in one go. I thought it looked about 50 / 50 that I'd be able to shufty the block out sideways off the transaxle. I'll have a big cuppa, and ponder that tomorrow. 4 Quote Link to comment Share on other sites More sharing options...
h4nd Posted October 20, 2019 Author Share Posted October 20, 2019 OSGCs @EpochNZ and @Bling helped with that problem. Cheers! Now I have this problem: which I can't solve with this other problem: Who says I have a 2T problem? So, to avoid further problems, I ran this up on the floor: https://photos.app.goo.gl/jcPet4fvTR2eTVBs6 No problem. Er, except how to get a now assembled engine into that impossibly tiny hole. Oh and assemble more bits on it... 6 Quote Link to comment Share on other sites More sharing options...
Popular Post h4nd Posted October 28, 2019 Author Popular Post Share Posted October 28, 2019 I've been yarning to a new mate about cars, bikes and so on, it turns out he used to race an RS125 and generally likes two-strokes. He came over Sunday and helped me line up the clutch, and get the motor and transaxle crammed together. In the process, some of the tiny clutch bolts proved to have stretched, and one failed. Being the handy chap he is, he drilled the remainder of the bolt, and noticed it screwed further into the flywheel doing so. So we smacked a cheap Torx driver in there, and problem solved. It wasn't until the next day I saw my set of ezi-out anticlockwise threaded thingies right on the peg-board, looking at me. So, on with the show. Everythings so tightly fitted that not doing everything in a particular order, or missing a bolt means disassembling other sections, or going backwards a couple of steps to re-assemble. E.g, the exhaust can't be bolted to its bracket once the motor and transaxle are together; it just wont clear the front quarter panel to mate up. That took 3/4 hour to drop the other end of the bracket and re-fit (just two bolts) because those bolts also intefere with others. Oil feed lower section, starter and ignition from the chassis (not the test jig), fuel lines, and throttle / choke cable, lube and install the clutch cable means I could start it, and back it up 10 metres, and then foward again into the garage. By Jingo, its a noisy crackle straight off the side of the block. It wouldn't start at first, and sounded like a weak battery. I knew the battery had just come off the charger, so I was confused, until I noticed the hot electrical smell. Yep, I had forgotten the chassis to motor grounding strap for the starter, and all that current was torturing some light guage wire somewhere. Have also changed the water pump for a newer one. I'm now just trying to get at least 1/2h a night done, for steady progress to running again. 12 Quote Link to comment Share on other sites More sharing options...
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