hello /diy/, I just have a few questions1. Are the amazon chinesium motors (like picrel) any good? Will they require lots of oil to keep running? A review mentioned a ratio of about 40:1 oil/gas. ("half a bottle" of oil every 2L of fuel)2. Is it better to source used motors from lawnmowers, weed wackers, backpack blowers etc? 3. what engine volume/hp should I get to be able to reliably propel a 125lb person (me) at at least 20+ km/h
just checked marketplace and there's 3 5 HP 2 stroke motors for sale, one working and all for 80 fucking dollars, wtf.
>>2880833those are 4 strokes and that lot isnt worth $25get a chonda clone gx engine
>>2880836wouldn't four strokes be better in terms of fuel cost?I can see that they're old and worn, but 80$ for 3 is kind of insane.
>>2880837theres realistically $7 in scrap there. those engines were taken off of shit for a reason. theyre likely fucked up and repair parts exceed the cost of a new chonda replacement not even counting time. that seller is on crack
>>2880836Honda GX clones are like 200-300$That's pretty much over my budget of 250 max.
>>2880841it must really suck to live in leafland
>>2880828you should find an single stage snow blower. i threw away a 2 stroke toro that had a 6.5. i wish i would of kept it just for a mini bike motor or something
>>2880854handheld or the ones that you push?
>>2880828What year are you living in?We have these things now, even if you want to cobble together one yourself, make it electric so you don't draw the attention of 50IQ cops.
>>2880838>theres realistically $7 in scrap there.You must live where scrap brings a premium!
>>2880882those cost 500$+, have less range in the cold, and are a bitch to maintain, plus cheap chinese batteries that might combust if punctured.
>>2880899they are pretty much a nightmare to get running just right. first off, the kits i have seen are designed to fit on a "cruiser type" bike frame. the u-bolt engine mount and sprocket connection are both low quality. ebay and amazon have sources for a sprocket bracket that bolts on the rear wheel, solid aluminum that ran around $50 when i built mine years ago.the engine mount constantly vibrates, perhaps weld the nuts on or fabriacte your own mounting bracket - i did so for a mountain bike and it worked "ok"I logged over 250 miles with a digital speedometer, top speed around 28mph. this was a 50cc Chinesium engine from a kit found on eBay (advertised as an 80cc depending if you look at cylinder size versus total displacement) i paid ~125usdmost places in the US will want you to register and license any vehicles with over 50cc of engine. on the one i got, you could swap a smaller spark plug and squeeze a little more speed on the top end or use a larger spark plug for more low end power. similar considerations for the rear sprocket.the issue with these kits is getting the front and back sprockets to align properly, or else the bearing will grind away quickly. the engine will have juuuuust enough power to bend the spokes out of shape on the rear wheel over time. I had this issue even with ~$100 worth of upgraded heavy duty mountain biking spokes put on the rear wheel. the engine needs to go thru a break-in period where you run a rich oil mix. you need to consult the instructions provided with the kit to read up on the recommended break-in period. IIRC, mine was approx. a 16:1 mix for at least an hour of run time. after than you can run 40:1 and get better fuel mileage than any hybrid out of any other vehicle on the road. assuming you put this on a bicycle, the top speed will be around 25mph maybe 30 with pedaling, which was kinda scary on the cheap Walmart mountain bike i put it on.
>>2880904>the issue with these kits is getting the front and back sprockets to align properlywell shit, any way to remedy or do this properly?I know that bicycle hub bearings aren't the strongest but that seems awful, should I just rely on larger wheels?
Just buy a Honda GX 120 engineIt has 3.5hp and thats more than enough for your project.They are used in many things and also gokarts. Its easy to use one of these and you can just buy everything of the shelf to build a drivetrain system for whatever you are planning to build.
>>2880828>Are the amazon chinesium motors (like picrel) any good? Will they require lots of oil to keep running? A review mentioned a ratio of about 40:1 oil/gas. ("half a bottle" of oil every 2L of fuel)They call them China Dolls or China Girls. They're fun, but you never know what you're going to get in terms of build quality. QC is essentially non-existent. Having said that, they can take a beating, and are fun to work on.The gas to oil ratio is a constant argument. There's a youtuber who I was watching when I built mine and he said 40:1 cradle to grave, which is what I did.>Is it better to source used motors from lawnmowers, weed wackers, backpack blowers etc?Depends on your level of expertise as well as your willingness to troubleshoot stuff to get it working. I'd recommend going the amazon/ebay route as you can get the entire kit, sprockets and all. Makes it way easier and can get you riding faster.>what engine volume/hp should I get to be able to reliably propel a 125lb person (me) at at least 20+ km/hIf you get one of the 80cc kits, you'll easily go 30+MPH which as another anon stated, is way too fast for a fucking regular bike(not to say I don't do it).>>2880836>>2880838Agreed>>2880882Stupid opinion alert.>>2880904This anon knows. OP, what kind of bike are you planning on putting it on? You want to ensure that you have good brakes.
>>2880904This guy is 100% correct, however depending heavily on what you'd call a "nightmare." I got an $80 ebay kit (not sure what they are now) running nicely on a women's style cruiser frame which required a lot of homebrew adapters, including plates I affixed to the frame with U-bolts so I could use V brakes. It was a lot of fun and actually reliable and strong once I got the (many) kinks sorted. But don't get too sucked in, just use it for cheap funThere is a huge online culture of builds, tuning and upgrades. Very useful for info but honestly the ultimate emblem of goofy-ass online boomer forum cultures. You could write a paper on it. There are several competing forums, both of which have maybe 10 self-made bigwigs doing 90% of the posting. Every day they emerge to throw down with each other all over again over the finest and most mundane of points. They have made it so that, with remanufactured kits, anodized, billet-machined upgrades and custom-produced bicycles, it is possible to build a high-quality gas bike. One which exceeds the cost of an actual running Honda moped on craigslist by up to $1000, even if your area is hipster taxed. It is a very funny, sad joke
>>2881012>the ultimate emblem of goofy-ass online boomer forum culturesDude, yes! I was telling my wife about that. I was honestly shocked that it was filled with so many boomers. I'd figured it'd be a bunch of alcoholics that were jerry-rigging everything to get it running to get to the liquor store. But no, all boomers, all the time. They have been very helpful though during my times of troubleshooting.
>>2881017I think there should be a correlary to the law that work takes exactly the amount of time allotted to it: Jim's hobby costs exactly his amount of disposable income available after cable and beer. I've seen hicks and ricers build pretty cool cars and trucks for less than many of these bikes cost, it's great
>>2881007>good brakesThat’s definitely a good point.My bikes got a solid aluminum frame as for the brakes, there is only rim brakes and no disk brakes. The rear brakes have a bit of looseness in the cable but the front brakes are responsive. I also think the rear wheel’s spokes are out of alignment since you can feel it on flat pavement when going at high speed (just a sort of wobbling) I don’t think rim brakes would be adequate, not like I’d be stupid enough to floor it on an icy sidewalk though. And yes, I’ve been biking by pedal in winter on icy sidewalks and compacted snow, which is about as fun as it sounds. I dunno, maybe assembling my own frame would be better (I’ve had experience welding so it shouldn’t be difficult). A friend of mine has a shit ton of spring steel from bed frames and a welder, I could probably just buy a donor bike for parts and make a more rigid frame from there. As for what brake type I should use, should I go with disk brakes or just rely on rim brakes.
>>2881030A/n/on here, don't fall for the meme that you need discs. Sure, they'd be nice, but a good rim setup will still give you enough stopping power to lock the wheels up with ease. Good means aluminum wheels (which you have unless it's quite an old bike,) fresh pads, and a good setup. If your brakes are post-mounted I suggest V brakes (picrel) because they're piss-easy to setup, very cheap and plentiful; they just works. Keep in mind they need matching "linear pull" levers which are different from what other brakes useBuilding a non-terrible frame will be tougher than you think, do it if you think it sounds fun and badass but not if you just want it to be better. If you do, best would be to make it a pit bike like in this pic->>>2880962and be religious about alignment.
Back in highschool with my friend we bought an old chainsaw for cheap because it didn't have the safety clutch brake and fixed it on the rear rack of an old bicicle with small wheels, i ground down the clutch teeth with a dremel to accept a bike chain and repurposed a brake cable as throttle.It worked pretty well once it was above a certain speed, tough a bigger sprocket would have helped.
>>2881057that's interestingAnyways, should I double the horsepower if I'm making a vehicle for two people?Design will probably be a trike for simplicity and stability if I'm welding it out of spring steel. Otherwise thanks for all the useful info.
>>2880841>>2880844>LeafMake friends with someone who works at Princess Auto and buy during a sale. Got a 7.5 HP engine for $160, tax included.
>>2880837>but 80$ for 3 is kind of insane.not really I once got 5 engines from craigslist. 4 worked after being refurbished and minor repairs. ended up being $20 each.>>2880838>theyre likely fucked up and repair parts exceed the cost of a new chondawrong, I have been able to fix about 90% of all 2 stroke and 4 stroke engines that I received as not working. just depends on how much time you want to spend, and how much money. almost any engine is fixable.
>>2880833everyone of those engines is fixable as long as the crankshaft bushings are not damaged.
