Video tutorial for centrifugal clutch installation on the 80cc Chinese 2-stroke motorized bicycle engine. Use a graphite infused chain lube to keep the centrifugal clutch operating smoothly, such as Yamalube On-Road. ecx.images-amaz...
Good video. Note that this centrifugal clutch kit is intended for use on one of several Chinese--made bicycle motors. These are all made with a manually-operated dry-plate clutch similar to that on a motorcycle. However, with a tiny engine and no gear shift it's rather difficult to start off, for the engine likes to stall. The centrifugal clutch allows you to get off to a very smooth start, for those three big clutch shoes are meant to slip (and they get hot.) The centrifugal clutch rotates the old dry-plate clutch, and that dry-plate clutch rotates the front drive sprocket. Yes, it requires a certain amount of work and a certain amount of mechanical experience as well. In general, if you can repair a bicycle or a lawmower you'll have enough skill to work on a motorized bike, which requires quite a bit of tinkering just to keep it running even without a fancy clutch.
TY Mark I was honestly wondering what the point was and you helped me remember someone esle said they lack the torque to start from a complete stop unless you pedal.
Yes. I should add that the stock clutch--the one that's lever operated--probably works much better with the 49cc engine if you're a 100 pound kid rather than a 200 pound senior citizen. It can happen to any of us, I suppose.
+Mark Kinsler but of course you have to pedal to about 8mph. these are not similar to motorcycle/atv clutches where you can rev and dump the clutch. they have very little gripping force
Wow thank you for telling us what it does cause for people who dont know what it does will now know an explanation should have been in the video. The video was a bit too long for my taste tho
This guy and his content is bloody amazing! Has anybody ever come across a guy as clear in his instruction as him? He is by far the best bicycle mechanic out there and the wat he teaches is the gold standard... In 2021 bicycle engines are all the rage now and only going to get bigger yet none of my pals from my club have heard or seen this guy! I'm sharing this to everybody and I hope this fella gets what he deserves and he might become a leading voice for the masses on mechanical issues. Awesome channel!!!
Great job. I love working on these engines. They are cheap enough for me to practice my tuning and modification ideas on. I think this is a great idea.
Great video Fabian. Your attention to detail is second to none. Good timing also, I am installing mine next week so that gives me time to order 4 more gaskets. So easy for one like my self with no experience to follow your tutorials and feel confident about doing a top notch job.
I am so thankful for this video. 8yrs old and still helping others! I’m finding that the 3 alignment posts on my clutch assembly appear to be longer than yours…too long to allow the cover to fit. I’m tempted to remove them and grind them short enough for the cover to seat properly.
Good morning, I have the same clutch installed on a 48cc engine. What no one mentions is that the nut (plug) on the stock clutch side housing is for charging oil into the system. Yes, this clutch is hydraulic. It needs lubrication and the oil it uses is centrifugal clutch oil, SAE 20W30. It must be filled with this oil up to the edge of the fill hole. Both the original clutch and the centrifugal clutch are in an oil bath and work perfectly. Greetings from Argentina!
Thank You for this video..! I followed your steps to the letter. You'll need those diamond bits from Harbor Freight on your wiz wheel to cut a hole in the gear. I thought this would work without the hand clutch nah unless the "2 positions" made it too tight? It does pull way better off the line, No more bogging .. the out put shaft bolt is 8mm fine thread less than 1-3/4" my kit came with the wrong install bolt.... peace
I'm considering doing this mostly because my stock clutch is slipping and this seems like the only decent upgrade that would permanently fix it. I already did the shift kit, and pull start, and upgraded intake. As a side note, I'd tighten the crap out of the flower adjustement nut before sticking the new cover on just so you don't get any more slippage from the original clutch.
The best way to drill the little oil hole in the bell bushing is to use a 2mm diamond bit and a dremel tool. Takes about 5 mins. and the bits are very cheap. You wont break it easy like the carbide bit either. It works great, I've done it many times. 10 of the bits in a pack is only about 6 bucks. Try it, Very easy..
This is great for people with knee problems that have trouble peddling on take off . I've been riding this style bike for a year and a half and I've never seen or knew the need for such an attachment . I love my bike and it requires much maintenance . This isn't for me now , but maybe later . Good video !
Great tutorial, i dont have a motor at all. But i watched it all as it was very informative. Only thing is please put some more lumens on the subject. A Led headlight would be the way to go. Thanks.
Given the relative ease of removing the clutch shoes, and the fact you mentioned you can go about 100km before replacing the lubricant, wouldent it be easier to just remove the clutch bell for regreasing when the time arives? similar to a car oil change?
I found out that the newer kits (possibly even the old style) do not need a hole drilled for grease Fabian. Cleverly enough they machined a bit of the gear part of the clutch bell so they could press it into the bell, they leave enough teeth at the pressed portion that the teeth actually act as full blown channels for the same grease that lubes the gear work, at engine speeds this actually presses lube directly to the one way bearing.
The issue, is not the one way bearing. The issue is lack of lubrication between crankshaft extension sleeve and the clutch bell riding surface. The one-way bearing is "not" a load bearing part of the clutch bell.
The bearings push lube down into the sleeve do they not? Unless the design of the kit I have is different from yours. Did your sleeve come with a hole drilled into it from the outside, about midway, to the inside, comming through the puller tools threads.
And as an additional question, if a person were to drill a couple smaller holes instead of just one larger, could the force of the gears meshing push grease through and onto the shaft reliably
So does this still use your factory clutch to drive the 10 tooth sprocket ? i just read through over 300 comments and didn't find the answers to any questions looks like you don't answer the majority of your viewers questions, your viewers answered more questions than you.
Does this mean that the original clutch is locked in place permanently so it doesn't slip or spin does that mean you don't need the clutch lever either or am I wrong.
Hi I am installing a centrifugal clutch on my motorize bike however I ran into a problem that I am not sure about when I install the extension housing my flower nut is hitting against the burge in the extension housing what I would like to know did you run into this problem when you installed your extension housing if so how did you fix the problem
I like these centrifical clutches but they have a couple of weak spots to them the mainest one is the one way starting bearing assembly when you get a couple of mm slack when you get slack between the roller bearings and the one piece that connects to the crankshaft it spins the the centrifical clutch Part when you go to pedal start it or roll start it the clutch slips like hell the most likely cause for this is the spring inside of it breaking or excessive clearance between the roller starting mechanism it's got a very hardend spring that you cannot find anywhere so you have to make your own spring but you have to put it on the outside of the clutch bell because there's no clearance near the small gear and tie it up with wires in order to do that you have to modify the roller bearing carrier to where you can fit a paper clip without the paperclip touching the inside centre Part where it spins but I'm working on a method where I'm putting the actual one way starter outside of the of the clutch I'm going to take a strip of metal bend it and Shape it to where it fits around the clutch drum and then I'm going to put some glue under it for traction and then clamp it down with the hose clampand then put a weight on the other side of the hose clamp so that the hose clamp is balanced when the engine spins and then I'm going to put some type of homemade starting cogs mechanism on and then when you pedal start it I'm going to put weights on the end of those starting cogs so that when the engine starts the starting cogs are going to pivot in subtract inword under centrifical Force but I'm also going to put light springs on it so that when the engine is turned off starting teeth arms will go against the outer starting mechanism I might end up putting a couple of RU-vid regarding everything I left out a couple of details oh how I'm going to go about the whole thing exactly
I must hand it to you Fabian you really know your shit, when I was looking up the shift kit I could never find anything on how to put it in on RU-vid, then I found your video and it was a grate help in making me decide if I wanted one or not, everyone was saying they are a waste of money, but they just didn't know what they where doing, and again with this clutch, you really make it easy for everyone thank you, YOU'RE THE SHIT! XD
+Crying Angel I'm happy to be of any help. The shift kit and centrifugal clutch are the best thing since sliced bread, and from what i understand SickBikeParts have the "Ultra Heavy Duty Freewheel Bearing" system for their shift kit, as an optional accessory, not that the shift kit isn't bullet proof with the White Industries heavy duty (rebuildable) freewheel bearing system.
Cheers, I live in QLD in very steep, dusty and rocky conditions and that's why I want a shift kit, and I seen the chain guides you made up on one of you video's for it, I'll be sure to copy it when I get my one. Oh and is the expansion chamber exhaust system from sick bike parts any good if u have one?
+Crying Angel The SickBikeParts expansion chamber is very good, but i haven't put it on the bike, as it makes the bike look like a motorbike, and there is no way that you would get away with it if the police pulled you over. Unfortunately, there is no way to easily hide an expansion chamber on the bike, so i'm just using the standard exhaust system, though with slightly modified baffles in the standard exhaust system. The chain guides are absolutely essential if the bike is going to be bouncing around over rough terrain.
Lol it will and a lot, my place is all hills and rocks, the standard drive chain has popped off of the guide pulley once already I was lucky i was going slow, the chain got stuck up in the drive sprocket I'm lucky it didn't crack the engine case, but I modified it and its good now, thanks again for the helpful advice man really appreciate it.
Hello again I did what you said about putting 4 gasket onto the clutch extension housing that did solve the problem I ran into another problem but was able to get that resolved that was with the small pins that goes into the clutch bearing what I would like to ask you now is when I turn the clutch where it's not engaging with the engine I notice that the drive gear turns do it suppose to do that also the clutch arm did you connect the clutch cable to that or you just left it alone without the clutch cable
I have this clutch and you do not have to do all that pre oil and drill hole stuff lithium grease thats it. I have hundreds of miles on my clutch and very re-greased anything. Its not a wet clutch system
hey fabian i just a got a clutch kit and does the extension sleeve just slide on all the way, cause mine stop and i cant get the second cover to go on when i put the clutch on
Can you tell me where I can buy that kit for installing a centrifugal clutch on my bike? Mainly the extension housing for the clutch. Thank you in advance!
Hi I have a question. I have a 80cc bike motor ok when I. Pedal and released the clutch the motor has to. Turn on right mine doesn't it don't turn on so if guys know how to fix it I will really appreciate that
I want to put one of these on my bike, I have an 80cc Roadstar kit bought off of Amazon. What happens with the old clutch? It just stays there? like a secondary, if I want to manually release the clutch? (it'll just run normally like an automatic clutch until I pull the lever in which case it will release and no power will be applied to the wheel?) Also, will I need to buy a pull start?
Nice, very informative. But I was wondering, since you already greased up the extension sleeve, is it really necessary to drill the gear and case for lubrication? I mean I know you'd want to periodically check to make sure everything is a go, and with regular motor bike maintenance wouldn't be too much out of the ordinary no? I'm just asking because I'm trying to find out if it's absolutely a necessity thank you for the very informative video. ☺️
So ive read thru the comments and watched the video and just want to be sure i am doing this right before i screw up one of the last available centrifugal clutches im goin to abbreviate the clutches as CC and MC so does that flower nut get screwed counter clockwise or clockwise n my application is on a dirtsurfer i have built myself with a jackshaft n the right size gears to retain normal ratios of a 45t rear sprocket so that i can use an internal 3 speed hub to help with hills n high speed n eliminate the need to move the chain from sprocket to sprocket n it keeps the chain from going thru my right ankle and instead raised up to go over my right foot toes i dont have any means to pedal it n wont always have a hill to jumpstart it so i have a pull start but im trying to keep down the number of cables that run to a sawed off handlebar i have one for gas one for brake n one to shift the rear hub so i really only want to have the centrifugal clutch operating is there anything i need to do to make sure the MC is engaged or allowed to spin freely at all times n allow the CC to only engage when given gas should i just remove the MC gear completely since i have a pull start and couldnt pedal start if i wanted to basically all the reasons i saw u had suggested to keep it are irrelevant to my application or will it interfere with the operation of the CC n about that flower nut if u suggest that i do remove the MC that would be gone correct n if u suggest that i keep MC gear does the MC need to be engaged constantly so that it will spin freely n how can i accomplish this without an extra cable and a clutch hold on the lever
Anyone else bought a cent. Clutch where the extension sleeve isn’t reamed for the taper on the crankshaft? Mine are just straight holes that don’t fit over the shaft
person I have a lathe so I machined mine to have a somewhat matching taper, I hope some of these sellers realize eventually because I watched an installation vid on here and theres was machined properly
@@person-ce8cr I would if you can find a way to spin the extension while grinding on it. The taper angle doesnt need to be exact because there's usually a small shoulder on the crankshaft it can butt up against to keep it straight, but you need to grind all sides evenly or it won't be centered. Though mine has become pretty wobbly after using it alot (0.5-1mm) and it still works ok. Lots of times I've spun things in a drill and hit it with a grinder at the same time as a ghetto lathe. But you have to take it really easy grinding or your hand will slowly start to bounce and it'll be off center.
I've been spending quite a lot of time, soaking up your great information tonight... Good job! I'm getting ready to buy a bike and engine and still wondering about the 66cc vs the Honda 49cc 4 stroke. One of the reasons I liked the 66cc Chinese engine was that it is less expensive but now that we're talking about adding another $80+ to the build.... It seems to me that the Chinese and the quieter 4 stroke are almost exactly the same price.....because the Honda, I believe, automatically has a stock centrifugal clutch ?? Do I make sense... Since you have thousands of miles on the 66cc engine, I'm very curious to ask for your opinion as to which engine I should buy and for what reason? Thank You!
Fabian F Hi where can I buy this Kit? I looked all over ebay and other pages but I cant seem find it or it is out of stock. Do you know where to buy it with maybe even shipping to Germany?
HardDiskLover The centrifugal clutch as well as pull start can be purchased through a number of vendors: www.bicycle-engines.com/Centrifugal-Clutch-and-Pull-Starter-Kit.html www.shopatvpartsonline.com/complete-centrifugal-clutch-assembly-bike-engine-kit/ www.rawmotors.com/Centrifugal-Clutch-p59.html
This video is great and helped me a lot with my own centrifugal clutch. I have a question: the one way bearing stop engaging after a ride. I have to pop everything open and clean the bearings (the five small pieces) to remove the grease in order to make it work again. Is this normal?
Good job!... I don't understand why you had to be so clean with the turpentine and alcohol though on those two parts??? There was no sealer/locking fluid/glue used.
The transfer of torque to the crankshaft extension sleeve is only from a friction fit. If there is any grease between the two parts the friction locking is compromised and the crankshaft can slip/spin inside the crankshaft extension sleeve, both causing a loss of drive and damage to the sleeve and crankshaft. If you want dependable reliability, you must make sure that the mating surfaces are absolutely free from grease or oil.
Sure got a centrifugal clutch kit ,it's not identical in it assembly as what is shown and I'm guessing it an original attachment to crankshaft appears bearing less on this one I've not seen many and can't be sure if it's fabrication is equal to what is featured no less likely it has to be or should be lubricated and I've planned to epoxy diamond to the fly wheel and geese the entire of the assemble at some point any. I've had some trouble with gremlins lately and my have to replace the engine entirely if I can resolve a port timing issue that may be cause for it not starting.That caused by attempts to force a sett of portion rings to seat with a ratchet I'd been patient with it and yet should have filed a few thousandths off the rings before reinstalling them assuring an easy quick reassembly.Well in short I should have taken time to study the assembly closely but simply did not and in basic research on the 66 it should have been disassembled and upgraded anyway the basics again a solid forged steel journal a few ounces drilled out of the crank counterweights at the very least.
My motorized bicycle has travelled over 55,000 kilometers in 4 years, so i am reasonably experienced with the Chinese 2-stroke engine commonly available with these kits. The piston and rings should easily slide inside the cylinder. If you need to force it, you are doing something wrong. Most likely is that you do not have a piston ring or rings seated in the correct position on the piston, as the rings sit in a very specific location and are kept in this location by an anti-rotation pin. If the piston ring is sitting on top of the pin, it will not want to slide into the cylinder, or certainly not want to slide into the cylinder easily.
Extension housing sleeve! Or just use a micrometer or stick or ? And measure then adjust bolt length. Just a guess but I bet your Dialy job has to consist with chemistry or design/engineering 🤔
thanks Fabian I thought that the centrifugal clutch replace the regular, because on the vid. you removed the set screw by the flower but and then you tight it ,so that engaged the clutch and the centrifugal clutch will do the job if you can ..can you explain the reason to keep it thanks for your vid. I'm going to get a engine gt5 ported and add the jack shaft I owed a trek 660 mountain bike with hydraulic disc and the frame looks a bit small do you know the minimum space need it to attached a engine thanks for the help
I do not recommend this i just tried this option cuz i couldn't get mine out either using a large flat head screwdriver with a 1+inch wrench to give me torque leverage to no avail n then tried the center punch n it span about one turn after over 200 hard shots near the edge and in the channel near the edge and it actually snapped the head off the bolt i dont know wtf is wrong but i have no idea how to get whats left out or y it was so hard it sounded like some were able to get it out with nothing but a screwdriver and the locking pliers im gonna look for that damn tool that was in the infomercials that removes bolts that have been sheared off n sink some money into it
You work the centre punch at tangent to the circumference of the bolt head, alternating between one side and the other side 180 degrees apart. Just look at the bolt head on the screw in my video.
Fabian F yea thats what i was tryong to do but i noticed just befor it broke that it was actually. rocking the bolt head back and forth and in doing so it must have loosened the metal to the point it broke i think it was just seized in there i dont see how else it could have been that difficult i know i was turning it the right direction but my other question was more concerning ill get the bolt out i just bought a bolt extractor from craftsmen
great video bruv. the only way these 2 strokes can be driven on the roads in ontario canada is to have one of these centrifugal clutches, hand clutch with pedals is illegal...totally bullshit but it is what it is.
I am unable to get the crankshaft extension sleeve on the crank shaft far enough to have the clutch housing to recess as much as is needed. I cleaned both the shaft and the extension as prescribed by you. Do I have a bad extension or am I missing something? Thank you.
Does anyone know if this kit from JNMotors includes the gaskets, especially for the new round cover? Their website picture does not show any gaskets. Also, how does this kit compare with the kit on PistonBikes website?
That helical gear is almost always very untrue from the factory and must be jimmied with quite a lot to get running true. Otherwise it causes much more noise, vibration and unnecessary wear.
Hi Fabian! Thanks for making this awesome video explaining the install! I just have a question I hope you can answer. Does the kit contain the crank shaft extension sleeve, or do I need to order anything else except the kit?
If you were going to put a centrifugal clutch on the right side anyway, why did you bother with the jackshaft kit? An old go kart I had with a 5hp B&S 4 stroke had a centrifugal clutch that looked like that with one exception, it had a toothed sprocket on the outside. I would think you could have done something of that nature and run directly from that to your right side drive sprocket, thereby eliminating several parts, headaches, and a lot of cost. I wholeheartedly believe in K.I.S.S. (Keep It Simple, Stupid) when it comes to mechanical things, the less parts involved, the less potential for things to break/go wrong. Was it a question of parts availability (or lack thereof), or did you just not think about it? No disrespect at all intended, I haven't even done my first build on one of these, matter of fact, watching yours and others' videos are part of my research on the subject (what works, what doesn't), and up until just now I didn't know there were centrifugal clutches available for the CG engines. But that being the case that there are, would that not be a possibility to greatly simplify things? Not criticizing, I'm simply asking because I truly want to know what's possible, and what's not.
hey all question to those who build them and sell them,,i just started building mine so what ball park figure do you sell yours at? don't see them to much on craigs list except the whizzzzer ..I just wanna price mine accordingly
How do you get the clutch apart to file those edges Fabian. Mine is brand new and I do not want to force it. I have already broken enough stuff learning by trial and error on this build.
There are two ways of going about it. The first method is to use a pair of flat blade screw drivers to try and force the clutch shoe disk away from the crankshaft extension sleeve by placing screwdriver tips in between the clutch shoes and the inner face of the clutch bell. This is a tricky procedure because it can take a very long lime to slowly wiggle the clutch shoes so the disk frees itself from the extension sleeve. There is also a risk of bending the clutch bell housing, which will cause permanent damage to the clutch bell. The other option is to use the crankshaft extension sleeve extraction tool (supplied in the centrifugal clutch kit) to remove the extension sleeve, as well as the clutch shoes in one single operation.
I used what was supposed to be a cobalt bit from eBay and a carbide and tungsten bit from home depot and only made a scratch on the surface. I guess I will have to forgo the oil hole unfortunately.
robert apple Typically the drill bits from eBay and Home Depot are only surface coated HSS drill bits. They are for the most part completely useless. A proper 2,5mm cobalt drill bit works out to be around $10 I also need to mention that a conventional single speed drill press spins too fast, and generates too much heat when trying to drill through hardened steel. You will need to use a multi-speed drill press, set to around 200 rpm, as well as continuously applying a light cutting oil (or transmission oil) on the drill bit and making sure you frequently pull the drill bit out of the hole to make sure it's filled with cutting oil. When starting the initial phase of the drilling process, you must be extremely careful because the very outside cutting tips of the drill bit (if stating out with a 2.5mm drill bit) will dig into the angled faces of the gear, and can tear away the outer cutting tips, causing the drill bit to become completely useless, in an instant. The hardest part of the drilling process is to very, very slowly cut into the angled faces of the gear teeth, till you reach the bottom outside face of the gear, i.e. till the drill bit just bites into the floor of the gear teeth. This very slow process can take up to 10 minutes - it's an agonisingly slow process, and the whole drilling process can take from 30 minutes to 45 minutes, just to drill one single hole.
No. Extension sleeve is bolted onto the end of the crankshaft with a single center bolt. The designers omitted both key and keyway, probably because there is insufficient room available and the torques involved with the centrifugal clutch are smaller than those when you're using only the disk clutch.
Mineral Tupentine (Turps) works just as well as gasoline, but it a safer option, as it is far less volatile than gasoline, and should it catch fire, it can be extinguished more easily.
You didn t grease your gears? i use PL 1000 grease on them.I did put one on.They don t site right.If you tight them to much,main slive will split.Great video tumbs up
The crankshaft extension sleeve will only split if applying excessive torque to the fastening bolt. This is a common problem for people who have no mechanical aptitude or are simply foolish in apply excessive fastening torque to the bolt.
You will find that when the crankshaft extension sleeve has been lubricated, the spray nozzle can be lifted out of the hole drilled in the helical crankshaft gear, and another squeeze of the nozzle will spray lubricant directly onto the gear teeth. That said, the gears will run dry in a short period of time, because they are not splash lubricated, as per a 4-stroke engine with a wet sump. From my experience, the helical primary drive gears will outlast the rest of the engine, so i no longer pay too much attention to the helical primary drive gears, other than to give them a spray of lubricant when i lubricate the crankshaft extension sleeve, which is approximately every 300 kilometers or every 186 miles. If the bike is used in heavy stop/start traffic, the crankshaft extension sleeve will need to be lubricated every 150 kilometers or every 93 miles.
