Thanks for walking through this - I just completed this step - I'd seen 2 other videos - but yours broke it down - the bit about making sure the pistons rings line up properly was my hang up - thanks for talking about that.
I just wish this video had been filmed with better lighting to see more of what you did on everything. It is so very dark in places that it is difficult to see exactly what you did, but none-the-less, this is a great video, regardless. Thanks for sharing.
So his videos actually awesome for me because I've already broke three sets of rings trying to get pissing on with the head but definitely I think I know how to go about it now and I've built three of these motors already so I should know that but either way he definitely help me out thank you Hughes
Wanted to say thank you for your time, as I've just completed my first build with the help of your expertise.Look forward to seeing more of your videos
@@thomasgannon711 . If you can see the clip and get a magnet to it is best but I'd never be that lucky. So...gas, acetone or any solvent will do. But yes. Take it outside and carefully add an ounce or two and swish it and dump it over until you find the clip. Avoid sparks, heat and flames for obvious reasons. Don't want you turning into a fireball. Make sure most of the gas gets out and try again. Good luck
I find, when installing the head gasket as well as the jug, you can press 1 or 2 of the bolts, whichever way they need to bend to get them to drop without forcing them.
can anyone answer this question? can i use 4 or 5 head gaskets to raise the cap if i dont have a high hole piston? ive got a long rod ,but a low hole piston. there ant tricks or treats some can educate me on?
@@kennethpeters3679 Get the correct piston. The bike will run poorly as the port timing will be off and that many gaskets will leak sooner rather than later is my 2 cents.
Thanks, I just a motor on my old 1955 Schwinn Black Phantom. Of Course the fit was wide and I had to fabricate a front mount to make up the space. 14mm impact sockets were perfect. I appreciate your how to videos and common sense keeping in mind these are inexpensive, cheap China made motors. Nice tips improving and maintaining them.
I have an 80cc engine. Runs great. Won't accelerate. When clutch is pulled in, idle is way to high. What can be problem with accelerator not working properly
Next one i buy will be a BBR bikeberry. They work all tha bugs outa tha engine with upgrade bearings before they ship em. Cost alittle more but atleast u aint gota overhaul it right outa tha box.
Hello sir and thank you for all your videos I appreciate them very much they're very helpful I have a newer bike I've ran 2 tank of gas through it I ran it when the spark plug was loose for about 2 miles bought a new spark plug put new gas in it it's getting gas but it won't turn over can you help thank you
I don't think you used any sealant did you? Building a Mineralli with no base gaskets (Permatex Motoseal) and 1 copper head gasket for a 1.10mm squish, so dry head gasket is fine? I flattened them with glass and sticky back sandpaper the best I could\ oh yeah, Got my full suspension build going well, , improving parts all the time . Check out the "Focus on the chain video". i think you will like it, Bro
If you have any desire to fall in love with the "China Doll" 2-Stroke again, then get yourself one of these StarFire SuperRat 70cc engines. From what I'm told, they address most of the main issues associated with the typical "China Doll" engines. Among several other improvements to the original "Happy Time", "China Doll" engines, these come with a High Quality, Die Cast Jug, with a Cast Iron Sleeve (I actually have one of these cylinders that I bought on eBay, and I can tell you without a doubt they are 10 times better than any stock/chrome jug I've ever seen), not to mention an upgraded Integral CDI Magneto. Now I haven't actually used one of these engines personally, at least not yet anyway, but it will be the next 2 stroke I buy. I was recommended this engine from an experienced builder who said that, "These will be the best quality "China Doll's" you can get for the price, mark my words." www.grubee.net/products/superrat-70cc-engine-coming-soon?variant=7094657744931
@@HughesMotorized From what my buddy tells me, they run better right out of the box than any other stock "China Doll" on the market, and will last significantly longer (granted you run & maintain them properly) without all the typical issues associated with these engines. Apparently Grubee listened to their customers feedback, as well as spent years researching the industry climate on social media. So by doing their due diligence, they became very aware of all the problems people were having with these engines, and subsequently the "SuperRat" is their answer to the problem. It will be their "Flagship Model" for years to come, and will only get better with time, as better components and aftermarket parts are starting to become more available due to the popularity and increasing interest in motorized bikes. The "SuperRat" will be (aside from the occasional defect) the best quality "Stock" 2 stroke "China Doll" you can get for the price. Right out of the box it will meet or exceed most people's needs/expectations. If you just need a reliable 2 stroke for getting around town, or just want to have a little fun, then it should work just fine for most people in stock form. That being said, however, with just a little upgrading/tinkering/modification, they can be very reliable, rock solid and surprisingly fast engines. If you add an MZ65 Pipe (or equivalent/better, don't be fooled by inferior imitations/clones, only the real deal MZMiami or quality custom made pipes will produce true "bolt on & go" performance, which will literally add an extra 1-HP or more depending upon the pipe & tune, but I digress), quality carburetor (doesn't have to be a "High Performance" carb, but a higher quality/better made carb, like a Dellorto, will allow you to tune the engine much more precisely, not to mention they are just all around better performing and longer lasting carbs, but again, I digress), and a CND High Compression Head (like a Fred or Jake Head, not really necessary unless you're doing the other upgrades I mentioned, however, if higher performance/speed is a goal, then these "upgrades" are a MUST!), a quality CNC high compression head can improve performance and especially cooling, more metal & surface area for heat to be dissipated, which is NEVER a bad thing for these engines.
Question for ya I got a 100cc gas bicycle motor off of Amazon last year and I just found out tonight that my piston do not go all the way down past the exhaust hole you can see the top ring and it covers up half of the hole what should I do and how would I fix it or can it be fixed
How not to put a head gasket on. Putting it on that way can cause the head gasket to shave metal from the threads you should put the head gasket on flush before putting the head on
I've 2 blown up ones and I'm trying to get them running again. I bought new piston and head gasket and cylinder and head and it's still hitting what's causing the problem? I never had changed the road can they stretch out
Awesome video, as always. I didn’t near you mention it, but do you recommend taking the cylinder studs out of the block and using lock-tight before replacing them to the proper depth? Thank you, sir!
I've always thought thread lock is fine for the studs. I seen Hughes using vise grips to grab them which is fine, I've done that myself but even with thread lock on the studs it's not that hard to back two nuts together on that stud to turn it out with a wrench. I'm actually surprised he didn't do it that way being as he had the motor mount nuts right there on the table which work perfect for turning them studs.
On my version my cylinder and head are All One piece and no studs so if I replace the cylinder and head do I have to also buy studs and having a hard time finding a a 1 piece design I only can find the 2 piece and can I do upgrade like from 80cc to 100cc
Hey my cylinder doesn’t want to slide down and I’ve been trying for 2 days and it won’t go down no matter how hard I press and the only thing I’ve done is replaced the top ring of my cylinder but everything else I’ve done as it should be done
I need help how do I find out the correct size piston. I have an anbull 100cc definitely a lie. Probably 80cc actually. I’ve heard it’s a bt100 motor. But I have no clue I’m brand new to this.
i just got a brand new Skyhawk .right out of the box o noticed some exhaust a small metal lip or flashing my gut says to port it i just dont want to take the hole jug off i have done everything else so it probably sounds silly .btw love ur videos
@@HughesMotorized i still love them though..its a hobby and a lot of fun once u get em right.ill bet a lot of people like myself.had that one perfect build.either stolen or lost in ways they could not control..i know i did.
i had a revaluation beach cruiser .66 Skyhawk .broke in so nice .never even had a chain come off..i kid u not 36 tooth sprocket after break in..that bike would do 50mph or more when it got to temp... NGK spark plug expansion chamber upgraded carburetor that's all I did I didn't do any porting but my next one I hope runs great I will update everyone on my page
Hi. Thanks for the video. Just finished assembly of my first chinagirl 66/80cc. I'd like to ask for advice - i've screwed the plug in, added few drops of oil on the piston and i'm able to turn the engine with the socked wrench on the magneto screw... With my bare hand. Some resistance but i think it should be harder. The point is - is the compession so low in those motors or is there a risk that i did something wrong ? I've put new gaskets for the jug and head. Screwed it in with a torque wrench according with your tips. Checked all the surfaces (jug, head, block) - they're even and smooth. What do you think is happening there ?
@@HughesMotorized Hi. It doesn't run at all. It's a brand new spare motor. I've solved the problem. I wasn't listening carefully when you talked about garbage corn nuts :) It's ok now. Thanks.
The flywheel and crankshaft require the rear wheel to move the chain continuously to start the engine, The weight of the flywheel adds inertia that I assume helps to accomplish some of that but the intention of the flywheel's weight is to balance the crank assembly at higher rpms
First time builder (everything is still in the box). My question is when you put the wrist pin and assemble the bearing and the rod and place the piston on top are you supposed to use any oil/grease before connecting the piston to the rod???
Have you ever shown bearing replacement? I think that if you put in good, or better bearings, balance the crank and maybe a few other things they would last longer!
Hard to say. The chrome bores are getting poorer and poorer on these. I've heard of 10,000 miles max and 100 yards the least. I suggest getting a spare engine and some spare parts and have a spare ready and it'll allow you to learn and improve.
@@HughesMotorized It's gonna be a fun/part time use bike. I won't be relying on it to get to work or anything like that. If I have to push/pedal it back a couple of miles, no big deal. Years ago with a Honda Spree I had, one of the carb bolts fell out while I was out riding. I zip tied it back on as best I could on the side of the road, adjusted the carb to make up for the air being sucked in between the engine and carb, and rode it home that way.
Thanks for all the tips, I just recieved my 66cc motor for my bike and yes it was disasembled, as I checked it out I found a cpl things odd. First off a broken ring, I ordered a set but they call it a 66cc set yet the engine says 69 cc, are the rings the same. Secondly there are two gaskets under the jug, should I just use one? thanks
Dude check this out if you stick a clean towel in the bottom of the engine you should not have to worry about getting stuff in there and I like to use hot water on the fuel line I heat some water in the microwave and soak the line in it for a few and it slips right on
Dear friend, i saw at ebay's pages, 2 stroke motorized bicycles kits for sale-brand new, something strange.The 80cc motors have 2,5 Kw power (5000 r/min) . and the 100cc motor has less (1.9KW), due to the description. Why is that?
Hey. So i just replaced my cylinder and cylinder head, everytime i try to start it, it squeakes like crazy. I tried without the spark plug, the squeaking was gone. Any advice?
hughes motorised, i have a problem on my 2 stroke 80cc. i replaced the piston rings,ever since the piston is hitting the head, both gaskets are on im pretty sure.
there are many. gasbike, Bikeberry has the one piece head motors. You can also get on ebay. I'll offer you get a silver one and spray paint it yourself. the black powder coating is so thick it causes problems
ive just gotten into these 2 stroke motors for my bike, and i bought it second hand, so i first off rreplaced the metal head gasketbut have yet to get to the lower cylinder to crank case gasket. so i`ve been looking up on upgrades and tweaks i can do cheaply, ive got a banana exaust, and replaced the stock carb with another of the same(NT) but as i`m looking for another piston and cylinder i got wondering if an 80cc(66cc) cylinder or the 100cc would fit on the 50cc crank case?seems like the 80cc piston and cylinder are easier to find and cheap, it would be great if i could drop the larger cylinder on my 50cc crankcase...would that work?
A question I have had for a while and no one seems to touch base on the subject would be which kit to order and from who? I am probably going to start by buying a cheap kit and then upgrade parts from there. Doing so, I want to find a kit for a decent price knowing that a good bit of parts will be replaced! He you would respond which lit would you recomend preferably under $150!
I just buy the cheapest I can get off of eBay. ThatsDax sells some great kits. I figure they all are cheap enough and if you sort thru them you can keep one going. If you get a dud, break it down for spares
@@sebbyyt6226 well I installed it broken and it scratched the cylinder and piston. At this point I've replaced it and it worked fine until a few days ago and now its not hardly accelerating any ideas as to why?
I dont much about these engines but is it possible to turn the cylinder head 90° so the carb and exhaust are east n west instead of noryh and south . ?
To be honest I've never used the 100s. Im sure they are OK. I just prefer having a removable head. Although lots of hybrids out there using 1 piece cylinders/heads running very well
I had a question I have a high compression head and I have a 66 cc engine the head is from a few years ago and I didn’t know if the heads were a one size fits all or if u need certain heads for different ccs I put it on the cylinder and the gasket doesn’t seem to smash between the cylinder and the head I didn’t know if it just meets with the cylinder on the circular edge or needs compressed the whole way between the head and cylinder?
Anyone, I need help. I had to fight my head on. It's not in 2 pieces, it's just one solid head and body. Let's say I forgot to put the needle bearing on (excitement and also it was in a completely separate box). How the hell do I get the head back off?
I also found an easier and more efficient way to put the piston in. Because I broke three sets of rings doing it the way Hughes showed in this video, I didn't put the wrist pin in until I had the piston set in the head just a little past the bottom ring. Soooooo much simpler for me lol. It's just a suggestion just in case you have never set a piston into a cylinder before. I am in fact making a video today on it cause I'm putting new rings on.
At 17:30, I AM having that issue, where the piston is hitting the head. Very strange, and don't understand how that can be. Add another gasket or two below the head?
Your doing that wrong. You put the piston in the cylinder first with the wrist pin hole below the cylinder skirt, then lower the cylinder to line up crank with wrist pin hole,then insert wrist pin and clips. Much easier.
If any are in the crankcase, you'll need to flush it out well or even best, split case and clean out. Then inspect the piston & cylinder and make sure they are good. Then build and go
sometimes the spark is very faint. Grab the plug and if you are screaming and cussing me, then you have spark. Failing that, the most often culprit is the magneto coil. 313 ohms with a multimeter between the black & blue. Also make sure the back side of coil is free f the clear varnish so there's a path to ground. Also make sure magnet is installed correctly. Remove spark plug and turn engine over till the pistion is at the very top. Called TDC. Make sure the key in the magneto is at the 1 o clock position. Sometimes they are put on backwardss
Pulling the piston out of the head is not a good idea IMO. You can connect the piston to the rod without having to pull the piston all the way out and unseating the rings. To Hell with fighting it later to get it back in.
