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ShaneB posted:Put the stock cylinder back on today, rejetted back to normal. Before I put it back on, I ground the piston skirts up on the parts that work with the transfers, so that they fully clear the transfers at TDC, and took the intake piston skirt up maybe a half mm. Got about 3mph more on the flats. See I wanna be able to understand this! Someday perhaps.
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Apr 12, 2010 00:24
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Senator Woofington posted:See I wanna be able to understand this! Someday perhaps. ShaneB posted:Put the stock cylinder back on today, rejetted back to normal. Before I put it back on, I ground the piston skirts up on the parts that work with the transfers, so that they fully clear the transfers at TDC, and took the intake piston skirt up maybe a half mm. Got about 3mph more on the flats. First, read this: http://www.vf750fd.com/blurbs/stroke.html I'll explain these things in order: cylinder: aka the "jug", this is the big finned piece between your engine case and the head. The cylinder has your intake and exhaust ports and also your transfer ports, and, perhaps not surprisingly, are what your intake and exhaust bits attach to. Different cylinders have different port maps. The piston is sized to the cylinder by its diameter and comes with the cylinder as part of a kit. Larger cylinders mean more power via the increased displacement, and frequently through better port maps. head: The finned piece bolted onto the cylinder, and what the spark plug screws into. The design of the head will cause different amounts of compression. More compression is usually a good thing, but can cause preignition of your fuel, which can lead to decreased performance and eventually a hosed engine. port map: The port map is essentially the size and positioning of the intake, exhaust, and transfer ports inside the cylinder. These are a Big Deal in terms of how your engine performs at certain RPM ranges - or at ANY RPM, really. piston: This thing goes up and down inside your cylinder, uncovering and covering the ports as it does so. The piston has (amongst other things) a head, rings, and a skirt. See this diagram, which is more complex than the usual moped piston:  . The rings provide pressure against the cylinder walls, which makes sure nothing blows by them and keeps your compression strong. The skirt works in conjunction with your port map to control your the port timing. Grinding down any part of the skirt will adjust when a port opens or closes, which changes your port timing.transfers: These things channel your air/fuel mixture into your crankcase and back out again, which does good stuff. Honestly this isn't my forte, I just know what happens. Read the page to find out more. TDC: Top Dead Center, when the piston is at the position where the piston head is closest to the engine head. What I did was look into my cylinder (with it off the bike), and saw that the transfer ports in the cylinder were still somewhat covered by the piston skirt, even at TDC. I took a dremel and ground the skirts up, so that the transfer ports were no longer covered. I also ground part of the piston skirt that covers and reveals the intake port, so that it closed a tiny bit later than it did before.
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Apr 12, 2010 01:11
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ShaneB posted:First, read this: http://www.vf750fd.com/blurbs/stroke.html WOw thanks a ton!  . Gonna read that through and through!
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Apr 12, 2010 04:36
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Senator Woofington posted:WOw thanks a ton! I forgot to define: kit: What one throws on a bitch. At the most basic level, a kit is a new cylinder and piston that replace your existing ones. Moving from a stock bike to a kitted bike will almost always result in greater top speed, and potentially acceleration, due to either increased displacement, superior port maps, or a combination of the two. Kits differ between each other by, amongst other things, build quality, port maps, and overall power potential. Kitting your bike almost always results in having to tinker with other things, such as your jetting. jetting: The air/fuel mixture, and the overall mixture flow to your engine, is managed by your carburetor. This is extremely important for a well-running bike. Too much fuel makes your bike run "rich", and "four-stroke", which is very noticeable and is caused by your engine detonating on every other piston compression due to a lack of air in the mixture. Too much air makes your bike run "lean", which can cause your engine to run too hot and eventually get damaged. A lean condition is noticeable by "lean bog", which is when your revs cut off and you lose power at WOT. A Bing brand carb came stock on Puchs, and many other bikes, and is probably the most basic option on a moped.  Looks complex, but it isn't. When you roll on the throttle, the carb slide (#3) moves up and down, raising and lowering the needle that sits inside it. The needle moves in and out of the jet holder, allowing fuel to come through from the bowl, which fills with fuel as is needed. This is governed by the float (#16), which floats on the fuel inside your bowl. The maximum fuel flow is defined by your main jet (#1), which is essentially a tiny screw with a hole in it. Different jets have different size holes. As you roll on the throttle, the carb slide rises, and air is sucked into the carb from the air intake side, which is what your air filter attaches to. This air flow mixes with the fuel flow coming from the bowl, which gets sucked up due to pressure differentials. Then it passes into the intake manifold (the little bendy bit that attaches your carb to the cylinder) and into your cylinder for combustion. WOT: Wide Open Throttle. This is when your fuel and air flow are at their peak, which means engine RPM and power production is at its peak. Running at WOT is how people check their jetting, as well.
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Apr 12, 2010 13:11
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Oh so that is how a carb works! My understanding was completely bass ackwards. But that makes a lot of sense. Thanks a ton!
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Apr 12, 2010 17:54
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There's a carb thread. i'd recomend poking your head in.
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Apr 12, 2010 22:24
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Nerobro posted:There's a carb thread. i'd recomend poking your head in. Right-o I'll be on the lookout. Now to do some reading up on Points inside the engine!
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Apr 13, 2010 02:09
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An 87 year old man cutting across an intersection hit me while I was blasting. I somehow avoided anything happening to my arms but my legs/hip were hosed for a bit. I had to swerve to hit his front right panel instead of the passenger window-bike stayed behind and I cleared his hood entirely. Helmet visor flew off and so did one of my shoes when I flipped. His fault totally...here's the aftermath, at totaled Newport II  ...   and here is my new moped Free Spirit w/ Proma exhaust(a work in progress-ordered new forks and shocks-may put the 65cc metra from my Newport on it):  low end is super sluggish but it rips at about 40 top speed.
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Apr 16, 2010 01:28
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Somebody care to identify the model/how hosed for parts I will be if I buy this? http://fresno.craigslist.org/mcy/1683193607.html
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Apr 16, 2010 09:28
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Rontalvos posted:Somebody care to identify the model/how hosed for parts I will be if I buy this? http://fresno.craigslist.org/mcy/1683193607.html It's a Peugeot 103. It will be possibly to find almost all parts.
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Apr 16, 2010 10:00
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heyleroy posted:An 87 year old man cutting across an intersection hit me while I was blasting. I somehow avoided anything happening to my arms but my legs/hip were hosed for a bit. I had to swerve to hit his front right panel instead of the passenger window-bike stayed behind and I cleared his hood entirely. Helmet visor flew off and so did one of my shoes when I flipped. His fault totally...here's the aftermath, at totaled Newport II NOOOOOOO it's like seeing my bike get totaled in these shots. Glad you weren't hurt.
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Apr 16, 2010 16:09
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Blaster of Justice posted:It's a Peugeot 103. It will be possibly to find almost all parts. Worth picking up for $300? Good bike to start with? I've got a motorcycle and will be on 2 wheels soon, but now that the wrenching on it is done (temporarilly) I have the stupid urge to buy something else to work on. Btw mopeds around here are few and far between. http://fresno.craigslist.org/mcy/1692795693.html http://fresno.craigslist.org/mcy/1692987771.html http://fresno.craigslist.org/mcy/1691941873.html This is literally every other moped else on craigslist.
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Apr 16, 2010 17:35
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Rontalvos posted:Worth picking up for $300? Good bike to start with? I've got a motorcycle and will be on 2 wheels soon, but now that the wrenching on it is done (temporarilly) I have the stupid urge to buy something else to work on. As a newbie I almost wouldn't get anything but a Puch/Puch variant, a Hobbit, or maybe a Moby. Something with lot of replacement parts and old parts lying around. Avoid Sachs, Derbis, etc. I've found my Puch to be quite easy to work on, and I appreciate all the new and used parts on the market.
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Apr 16, 2010 17:39
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Rontalvos posted:Worth picking up for $300? Good bike to start with? I've got a motorcycle and will be on 2 wheels soon, but now that the wrenching on it is done (temporarilly) I have the stupid urge to buy something else to work on. Those last two are not mopeds, but you've got an M-endorsement, so as long as you know you're gonna have to register them, they're perfectly fine bikes.
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Apr 16, 2010 17:45
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I love craigslist. I emailed the guy with a bulleted list of 7 questions and all he says back to me is. "I don't think it was ever registered. There is no title." Being in california, what kind of clusterfuck can I expect this to be? anybody know?
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Apr 16, 2010 20:51
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Rontalvos posted:I love craigslist. I emailed the guy with a bulleted list of 7 questions and all he says back to me is. Edit: Sorry, somehow didn't realize I was in the 'ped thread. Not sure if normal bike rules apply to you guys.
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Apr 16, 2010 21:49
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As far as 'peds are concerned, I'm in the dark what with specific model information. There's a Puch Condor on my craigslist for $100. Tires, chain, and sprockets are in good condition, the bike has compression and spark, but won't turn over. Just sounds like a carb cleaning to me. Anything Condor-specific I should look for when I go check it out? edit: Also, would I be able to find proper conversion parts to make it into a tiny supermoto? edit2: goddammit someone sniped it out from under me 
AncientTV fucked around with this message at 22:13 on Apr 16, 2010 |
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Apr 16, 2010 21:57
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ShaneB posted:NOOOOOOO it's like seeing my bike get totaled in these shots. Glad you weren't hurt. had her so clean too thanks. may swap out the 65cc metra onto my free spirit. that'll take a lot of tinkering though since i'm going from a 2 speed to a 1 speed. thank goodness for choke.
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Apr 17, 2010 01:08
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AncientTV posted:As far as 'peds are concerned, I'm in the dark what with specific model information. There's a Puch Condor on my craigslist for $100. Tires, chain, and sprockets are in good condition, the bike has compression and spark, but won't turn over. Just sounds like a carb cleaning to me. What do you mean it won't turn over? I'm sure everyone else here knows I just don't and I wanna get in on this lingo! edit: Oh sorry about your potential ped.
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Apr 17, 2010 02:23
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OK guys I need some help here. So I have figured out where and what my points are. As far as I understand, my points are two pieces of metal (with rounded ends) with one moving arm. As the flywheel spins, the arm closes and opens so the points touch and then don't touch. So first thing I did was I took one of those voltage deals (that checks if a circuit is complete etc), and when the points were closed, power was being transferred between them, just as I suspect is wanted. However when the points are open or there is a gap between them I checked the power and it was still transferring as though they were touching. I couldn't figure this out. So I resolved to remove my flywheel cover. Problem being I need an extractor tool. I'm assuming its just a pressure fit cover. I need a tool with threads on the outside to screw into the center of the cover and then pull off. I managed to get the nut off but that is as far as I got. So any ideas? Any help? I'm going to another auto store today to try and get a new spark plug. Are my points busted? Do I completely misunderstand what is going on here? This is getting frustrating!
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Apr 18, 2010 18:46
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Senator Woofington posted:Things. Yes, there's a special 17mm extractor tool to remove your flywheel, and you can't remove it without said $20 tool. Before you invest that much, please consider buying a workshop manual. Nobody can tell you whether your points are "busted" or not without pictures.
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Apr 18, 2010 21:54
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Blaster of Justice posted:Yes, there's a special 17mm extractor tool to remove your flywheel, and you can't remove it without said $20 tool. Before you invest that much, please consider buying a workshop manual. workshop manual? I have the manual for the bike. And indeed that is what it says I need. I was hoping there was a way around it.
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Apr 19, 2010 02:29
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The points closed:.jpg) The points open: .jpg) I realize that the points are not fully closed, because I had to shift the flywheel to get a good image. They do make full contact it does seem. So my question is if I place my continuity meter here and here:  Should I see power being transferred across the gap when the points are open? Is the very end, as I have the arrows points at, on my points insulated from the housing of the points or is it all connected?
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Apr 19, 2010 19:12
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Senator Woofington posted:What do you mean it won't turn over? I'm sure everyone else here knows I just don't and I wanna get in on this lingo! "Won't turn over" generally means it chugs and chugs but just never catches, i.e. the engine turning over. It can also mean the bike is a catastrophic basket case with a frozen engine 
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Apr 19, 2010 23:54
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AncientTV posted:"Won't turn over" generally means it chugs and chugs but just never catches, i.e. the engine turning over. if it's frozen, it's not gonna chug either :P
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Apr 20, 2010 00:33
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AncientTV posted:"Won't turn over" generally means it chugs and chugs but just never catches, i.e. the engine turning over. I love when people say "it fires but wont turn over". OK......
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Apr 20, 2010 01:30
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I need some opinions on what I can and can't do with a motorized bicycle here in Arizona. I did some researching at the Arizona Revised Statutes. Definition of a Motorized Bicycle does not require a Title, registration, or insurance and can be used in bike lanes. The helper motor cannot exceed to 48cc and may not exceed the speed of 20mph. Definition of a Moped does require a Title, registration, driver's license and insurance. It is not allowed to use in bike lanes and the motor may exceed 48cc and speed limit of 20mph. So I want to use a motorized bicycle as a primary transport because it's way cheaper and can fit it in my lifestyle. I'm wondering if I get a motorized bicycle with a engine more powerful than 48cc, and go ahead get the necessary license, title, registration, insurance, headlights, taillights and etc. would I be allowed to go on and off bicycle lanes provided that I turn off the engine and pedal in the biking lanes?
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Apr 20, 2010 20:53
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Don't. Unless you really really like talking to the police. don't.
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Apr 20, 2010 21:05
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I just indeed threw a kit on my bitch - an old unused 70cc treats kit a guy I know had. I'm trying to break it in as well as I can, varying the revs and not going hard on it for more than a few seconds. I've read a bunch of different poo poo regarding kit break in, so my general philosophy is "vary the revs, don't ride at WOT for this tank or so". I'm getting a legit 70cc head and head gasket this week sometime, so that should be a good amount better than the 50cc head and a bunch of base gaskets. It's definitely not tuned correctly, though, I think it's a bit rich right now. I have to back off on the throttle to make it rev out, which has been my experience with a rich mixture. However, the cylinder and head are getting incredibly hot, which makes me afraid to downjet and risk seizing. I currently have a 15mm bing and a 14mm intake manifold (the ZA versions only came in 12 and 14mm), but I'm getting a 15mm square port intake manifold from a E50 and making a riser out of my old 12mm intake. I think the square port to square port, plus 15mm size, should be better at delivering the mixture from the carb.
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Apr 20, 2010 21:21
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Blaster of Justice posted:It's a Peugeot 103. It will be possibly to find almost all parts. you can practically build a whole 103 via https://www.1977mopeds.com , if you need any help you can call them via the 800 number listed on their site, awesome dudes. speaking of 103's heres mine before WB3:   
Unreal Fantasy fucked around with this message at 10:21 on Apr 21, 2010 |
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Apr 21, 2010 10:09
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Unreal Fantasy posted:you can practically build a whole 103 via https://www.1977mopeds.com , if you need any help you can call them via the 800 number listed on their site, awesome dudes. Dude you should really have told me you were on these forums, too. Look at my username, man. Or are you the guy who rode to WB3 with J? I don't think he has a 103, now that I think of it. ShaneB fucked around with this message at 12:55 on Apr 21, 2010 |
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Apr 21, 2010 12:52
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 HUGE UPDATE!Got my derbi's motor running!!! So I managed to figure out what was wrong electrically. For whatever reason, if my rear break handle is engaged at all, it shorts something. The spark plug won't fire with the handle pull in at all. However if it is pushed out, then I can get a spark. I installed my new carburetor and ran the engine. For a while at first nothing happened then I heard a "POP!" I got excited and kept kick starting it till eventually it fired and ran. It didn't run well, it sounded irregular and like it had a lot of power issues. I am guessing this is because it has no exhuast. So any suggestion or ideas on why my brake is doing this? How can I fix this? Well I am heading over to 1977moped.com right now to order myself a new exhaust! OH GOD I AM SO EXCITEEDDDD!!!!
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Apr 21, 2010 20:10
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Look at the wiring diagram for the bike, and look at where the brake contact wires should plug in. Then look at your bike and see where they are actually plugged in. Unplug them and make them match the wiring diagram. Easy as that.
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Apr 21, 2010 21:49
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Phat_Albert posted:Look at the wiring diagram for the bike, and look at where the brake contact wires should plug in. Then look at your bike and see where they are actually plugged in. Unplug them and make them match the wiring diagram. Hmmm yeah I was thinking something along those lines. The problem is, I don't really know exactly how to read one of these deals, been looking it up online and I can sorta kinda read it. Its slow but I think I'll have it and luckily my manual has a pretty clear and concise wiring diagram. Thanks for the advice! So excited to hear this thing roar! edit: I think I have narrowed down the problem. OK I thought I had found it but it didn't do anything. How do I figure out where the break contact wires are? It seems to be wired pretty much to spec in the diagram. What am I missing? Yeah I found a few connectors where the break wires plug in. I tried reversing them and it did nothing. There is a whole gloop of wires and connectors that were wound in electrical tape and bound with zipties that I let loose. There are so many connectors there, and their colors are faded. It is incredibly hard to tell if this is where the mix up happened. What would cause my breaks to cause ignition to stall? I have tested both brake handles, and if either of them are depressed, then the spark doesn't spark. But when let open the spark plug sparks. The weirdest thing is that my brake light functions properly. 
Senator Woofington fucked around with this message at 01:19 on Apr 22, 2010 |
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Apr 21, 2010 22:58
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Dont go randomly unplugging and replugging things, then you'll really gently caress yourself. Can you post one of the wiring diagrams you've been looking at?
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Apr 22, 2010 02:03
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Phat_Albert posted:Dont go randomly unplugging and replugging things, then you'll really gently caress yourself. Haha I actually got it fixed, I found what I believe to be what you talked about reversing. Turns out my brake light and parking light wires were reversed and caused something to always be grounded when it shouldn't have or some such nonsense. Now she runs like a bueaty. And she is running consistently now. Got myself one of these: http://www.1977mopeds.com/product/1667/Derbi-Variant-Metrakit-Exhaust/ coming in the mail as well as a new chain. Now all I gotta do is tweak and tune all the brakes and brake lines, and overhaul the tires. Then she'll be ready for the road! double edit: What do I do if my engine idles too fast? I notice that even at idling the gear that drives the chain still spins rather fast. super mega ultra edit: In california do I need to register this bike or anything? Do I need like liability insurance? Is any of this enforced? triple edit: What does a decompression cable do? I can kick start my bike easily with it released, but when I engage the lever it makes it hard to start or if the engine is running slowly kills it. Senator Woofington fucked around with this message at 04:10 on Apr 22, 2010 |
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Apr 22, 2010 02:41
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Senator Woofington posted:
Senator Woofington posted:triple edit: What does a decompression cable do? I can kick start my bike easily with it released, but when I engage the lever it makes it hard to start or if the engine is running slowly kills it. On a four stroke they work by holding a valve open. I'm not sure how the one on your bike works, but on some two strokes the head has a small hole in it(allowing some of the air to escape) that is uncovered when the decompression lever is used. open24hours fucked around with this message at 09:50 on Apr 22, 2010 |
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Apr 22, 2010 09:36
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Hmm so my engine is running but there is definitely a fuel leak somewhere. I'm not sure how to find it cause for some reason finding fuel leaks is tough! Also any moped riders down in San Diego? I live in North County and would love to form a crew/eventual moped army branch.
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Apr 24, 2010 04:42
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Senator Woofington posted:Hmm so my engine is running but there is definitely a fuel leak somewhere. I'm not sure how to find it cause for some reason finding fuel leaks is tough! No, it's not. Show me a picture of your float valve surface before you catch fire.
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Apr 25, 2010 18:12
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Blaster of Justice posted:No, it's not. Show me a picture of your float valve surface before you catch fire. OK, I am trying to learn, but the float valve is the part also called a "banjo" right? My carburetor is brand new and in pristine condition! Otherwise I might have no idea what I am talking about. It is cool and crappy starting a project like this with no prior knowledge.
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Apr 25, 2010 18:25
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