C90 Clutch Actuator

Correct parts order for re-assembly. It's a common problem to get a jerky gearchange if someone has assembled this incorrectly in the past, uncorrected you will eventually bend the selector forks and have no gearchange at all - simple test to see if your bike has this fault; Hold down the gearchange lever after selecting first and rev the engine - if it tries to pull away then you have this fault.

[@SAM-zt2uy]

Super helpful thanks! Wanting to swap a manual version of these engines for a semi auto and after watching a handful of videos this seems to be the first one showing the shifter clutch assembly.

[@Realrandomman]

Great explanation. I managed to assemble the clutch on the bike with it leaning very slightly to the left. The oil held the clutch release mechanism in place well enough to replace the cover.

[@xmoroseguyx]

You right about being careful not to overtighten things, The part that my brother stripped on my 1998 Honda C 90 Was the rear axle sleeve, Only cost four quid to replace though

[@jeffkesel7217]

Perfect! Exactly the information that I was looking for- Thank you!

[@petemietz7967]

Thank you, thank you, thank you!! Just bought a CT70 & I've been working on this Issue for days! Like you said....some bone head had it assembled wrong. I even rebuilt the clutch and played hell getting the case to line back up with the motor still in the bike. The lay it on its side works like a champ! Now it runs and shifts like new:-) great video!

[@SilverMt.]

thank you so much all the way from from Kansas with a 1970 CT 70. really helped me. and some good tips. hope this Corona Virus stuff goes away for everyone.

[@Gordon_Gekko]

Thank you very much for this video. I managed to assemble my engine with ease. As you said Chinese engines do have different acutator, it is reversed so "ball like" parts stay attached on the cover and the whole mechanism do not run away - so they actually improved it :o the good news is that it is interchangeable so I had no problem to attach Honda cover with the whole mechanism into Chinese engine (original Chinese cover was to wide to screw foot rest), works perfectly without any clutch adjustments :) Cheers!

[@themuz3]

very helpful on my oil screen change.

[@jackturner5890]

Cheers for such a great reply time and I'll have a lookie at it soon and it's been stored for 5 years but was looked at and I was told it could be my feet sitting on the shifter when changing gear.

[@jamesfox1514]

Just used this for a repair on a CT90 - you saved my life there - thanks

[@R.S.407]

Im fitting a new filter screen on a C90 i bought and i guess the clutch cover hasn't been removed in thirty years from new, removing the old gasket is a complete pain in the arse

[@paulanthony2920]

Thanks so much for the video. I was in exactly the predicament you mentioned with most of the bits lying on the floor thinking "oh shit". Nice 1!!

[@stevenkeeler269]

This is exactly what I've been looking for

[@alexward4618]

My boys have an XPro go kart with the same setup as yours here. But I do not see the 3 ball bearing piece and the keeper I’ll call it that seems necessary to hold the shift lever in place. Looking online for a new clutch, most are not sold with these two parts either. Is this only necessary for multiple gears, or do I need it?

[@dannydelrosario2759]

gracias broth ...me salvaste de pagarle a un mecanico...yo arme una pero el sprin lo puse en otro lado equibocado pero ahora ya veo donde va ..... muchas gracias

[@concretecurt]

Well done, and thankyou for that informative piece of video.

[@jackturner5890]

I just took the gear selector off and found loads of dirt on the thread and cleaned the thread and the selector thread and it ran better in second gear and 3rd, and the thread was fine. But selector still isn't 100% there as it didn't pop up by itself and there was no slips.

[@specforged5651]

Exactly what I needed. Thank you. Question. I believe when I took it apart, it was stuck in 4th (drum screw had broken) is it best to try and get it back in neutral and reassemble or what should I do there, I’m not really sure? Also, I see there is a mark (it looks like a timing mark) on the large countershaft sprocket. Does that need to be aligned with something in particular (it seems it shouldn’t matter in any way, but I just saw the mark and wondered. Thank you for your knowledge and help. I appreciate it!

[@tubeuser10001]

Thank you for taking the time to do this. Saved me!

[@CalgaryDynastar]

Thanks so much for this guide! Was a huge help:)

[@johnsonspeedfab]

I have an 01 XR50 and it seems that my actuator arm that goes on the shift spindle is actually contacting the front plate on the clutch pack. Any idea why this is? I had to use a shift spindle out of a Chinese 110cc engine but I figured they would be the same? Any information would help. I’m stumped

[@gertstrutz7082]

Hi Dave, could you please help me? I opened my c70 1975 bike, to clean the filter. But now the clutch pedal is extremly soft and there is no change wheb I adjust the clutch nut. Its like its overclutching in every gear change.Also, when im going down on a hill engaged in a specific gear, it is very hard to go from 1 gear to second and 2 to 3. I must stop or reduce a lot my speed to engage the next gear. Please give me a hand!

[@williamlambert1711]

Great video Dave. I have replaced my clutch. All done correctly - but now I have a "whirring" noise from the engine. Very annoying as I really took my time doing the clutch change. The noise only goes away if I put pressure on the gear lever with my foot. Up or down the box. As soon as I take my foot off the gear lever - the noise returns. Have you ever heard of this ? Any ideas ?

[@cramersclassics]

I think your clutch is not adjusted properly. When you press the shift lever down the clutch should disengage. Try re-adjusting the clutch setting with the lock nut and screw.

[@Allemay]

Thanks so much for doing this. I was screwed.

[@15minutemechanic]

+DaveSluggy I am new at clutch repair and this video clears quite a few things up. I'm currently working on an Icebear 125cc atv which is similar to a Cooster 3125r. It's an auto unit with reverse. I see new clutches listed as for semi auto or fully auto. Am I to assume those clutches are one in the same? Also, I pulled the cover off and noticed I had no spring or triangular metal ball guide. Is that normal for fully auto's or has someone previously f'd with this thing?

[@DaveSluggy]

If yours is based on the chinese pit bike type then the 3 balls plate is replaced by a 3 roller affair that's mounted in the outer casing. That type doesn't fall apart when you remove the casing but also doesn't self align.

[@sumabrowns]

Hi Dave, I have a problem reassembling my 1969 ct 90. The small spring with its little tube doesn't fit inside like on yours. Am I missing a bit or is there a technique for the earlier ones. This seems to be stopping me getting the clutch cover back on. Help!

[@DaveSluggy]

Earlier versions are very different as they are a manual setup.

[@sumabrowns]

@@DaveSluggy thanks. I have sorted it out!

[@tmac4891]

Thanks. Another great video. Very informative. Which is better? Grease or oil on the gasket?

[@xmoroseguyx]

The kick start only, And the electric start are different internally as the electric start has a heavier flywheel to help charge the battery

[@DaveSluggy]

Nope, flywheels are about the same weight, just the added weight of the one-way ramp and roller clutch on the back of it. All other parts are identical - even the cranks are interchangeable.

[@pmgcleaningservices2322]

Did u do a video on the actuator clean

[@randylee1047]

Today my friend, your an american hero lol thanks man.

[@chuckbrown7570]

Awesome, takes all the time out of details..thank you

[@jameskent1151]

Excellent video!!!!

[@rubenotecamorales]

Gracias por su esplicaciom lo necesitaba

[@davidmilliken573]

Have a kawasaki bayou with clutch issues have replaced the primary and secondary clutch but still slipping any ideas ?? It’s a 185a bayou semi auto

[@sagittariushorse1088]

Thanks so much Dave. You've been of great help to me. Best of wishes

[@gongawoo5265]

I'm leaking small amount of oil from the adjuster nut, how can I stop this? crf70. 2005

[@DaveSluggy]

There is an o-ring on the adjuster shaft, to replace it you would have to remove the cover. You might get away with putting a fibre washer behind the locknut on the outside - it's worth a try.

[@niagarafallscarclub8628]

I have a 50cc planters and just put it all back together and when I put it in 1st to push start it the tire will not soon engine ...any idea ?

[@Halfday50s]

Hi DaveSluggy was wondering if you could give me some advise as to what would be making a rattling sound coming from the clutch, engine starts and idles fine, but rattles when revved up, gears work but bike drives slowly through them, feels like clutch is taking ages to release after each shift change and the bike slowly dies like its running out of fuel, but stars straight back up to do the same again. Clutch works when I have foot pressed down on lever, rev bike and it doesn't move, but leave it for a few moments ticking over in first or second gear and the bike will eventually start rocking and trying to creep forward. Have read through all the posts below, regarding adjustment still to no provale, any help would be appreciated.

[@DaveSluggy]

This sounds like a complicated one to diagnose, if your certain the adjustment has been done properly then you really don't have any alternative but to strip it down and take a look at the innards. Especially check the bush that the primary gear runs on behind the clutch - this can wear and cause all sorts of problems. Also check the flyweights are free to move and the springs have not 'settled' causing drag.

[@rashawnwhite4834]

DaveSluggy can u tell me what that part was on 7:28 and where to find it please

[@makenziebeqir9473]

would it grind when i shift down if i have put the flange side up on the three ball thing?

[@harrellsmith9929]

Hey Dave, where can I Find that that spring mechanisms that goes into the clutch bearing to control the oil flow. is there a specific name for that part

[@DaveSluggy]

Have a look on the CMS diagram page and see what all the parts are called.

[@shgoulding]

Great videos ....Quick question on adjustment as there's so much conflict ...when you say open outer nut and adjust flat head in ...I'm presuming clockwise ?....as everybody says clockwise until feel adj then all way back anti clockwise until feel adj then clockwise 1/4 ?....I'm going mad with advice !!....ha

[@rvabmx]

Super helpful vid. Can you explain how this type of clutch works in general? What is happening when the arm pushes on it? I'm having trouble finding a description of how the thing works. I've also put this back together twice and made sure I exactly did it in the proper order and everything is in the correct direction but I've still got no clutch disengagement. The bike just bucks and will go under throttle even with the shift lever held down. Ive tried various different adjustments on the adjustment screw on the outside of the cover as well with no luck. Any help on what to look at next that could be my issue?

[@DaveSluggy]

Hi, I'll try a brief description... Essentially it's a standard wet (runs in oil) motorcycle clutch so it has both friction and plain steel plates pressed together by a set if springs. Hondas genius was to add a centrifugal actuator (originally these were little rollers running up ramps but latter (12v) have swinging bob weights.the next bit of genius was to include a set of ramps that allow the kick starter (also allows bump starting). The lever from the gearchange shaft actuated the clutch as it forces the ramped fork to push against the little '3-balls' device, depressing the clutch outer and releasing pressure on the plates so the clutch slips. The last feature it has is to contain an oil centrifuge type 'filter' to keep the oil free of debris as the oil feed to the crank runs through the clutch centre. How's that!

[@rvabmx]

+DaveSluggy Thanks. Yea I could sort of guess at the functionality based on all the other bikes I've worked on. The 3 metal balls get rotated by the actuator arm and the indents on the triangular plate force them to push on the outside of the clutch pack and release the grip between the plates, right? My bike seems to be lacking this functionality in any way when I use the shifter. I more or less feel like I'm jamming it in to gear and the wheel spins whenever it is in any gear besides Neutral.

[@DaveSluggy]

+Sean Berg most likely it's an adjustment issue, a lot of places on the WWW have the adjustment instructions backwards. Slacken the locknut, screw in the adjuster to free the mechanism, then unscrew until you feel it contact, then screw in 1/8 turn and do up the locknut.

[@mountfields]

Hi.on our atc110 there is a noise coming from the clutch side which goes when light pressure is put on the gear shift, any ideas ?? Ps, all gears work/change fine...Thanks for any advice , (Taunton uk)

[@DaveSluggy]

It sounds like the adjuster is loose and you may need to take the slack out of it. Or the anti-rattle spring has been missed out or broken.

[@nickcantalejo6776]

why my fixed clutch still slipping i converted it to manual clutch but still slipping the clutch linning do i got wrong whith this

[@a19vuu]

Wish I had a spare electric start engine, previous owner didn't lock the clutch nut locking tab, clutch came loose damaged clutch actuator assembly, timing chain snapped, inlet valve met piston and theres a load of fine aluminium powder in the sump and centrifuge. Only got three weekends of riding out of it :(

[@DaveSluggy]

a19vuu In that case I wouldn't dick around fixing the motor straight away, loose clutch or flywheel usually wrecks the crank and a new one is really expensive - buy a 110 or 90 semi pit motor and whack that in as it will get you back on the road in a very short time.

[@a19vuu]

+DaveSluggy thanks, I bought another C90, a 89 C90-MG which was someones abandoned project. frame is rotten at the back. Hasn't been on the road for 5 years. I fitted it to my Cub and it won't change gear with the engine running. fine when the engine isn't running though. I tried adjusting the clutch, refitted the actuator assembly but now I'm stuck as the clutch still doesn't work. any ideas? there is a black tide mark where the old oil was on the crankcase/clutch cover. could my clutch be stuck solid?

[@DaveSluggy]

a19vuu Could be the clutch plates are stuck together or the spacer/bush on the primary gear could be missing or worn.

[@mettiouinawal3624]

5 3ةز2_غع5

[@diego198088]

Me pierde aceite en mi c90 por la tuerca del embrague, que puede ser?. Gracias

[@blaine5162]

so I just bought a new Lifan 125cc and i realized that when I put the shifter rod on i can't get the bike to change gears. I cant even get the clutch to engage. All it does it move maybe 1/8 an inch and total stop. I have adjusted the clutch and it doesn't do anything. Does it need to get running first? Are the plates just stuck together and will unstick with it warmed up? It is a semi auto Thanks.

[@DaveSluggy]

err, Shifter rod????

[@27speedracing59]

Hello i'am from Indonesian how to give manual clutch in CT 90

[@bentleyboy4072]

Hi Dave, great video. Do you have a video on kick starter spindle replacement...

[@DaveSluggy]

I don't but I think Alex does - look up The Alexman video's

[@johndoherty8681]

hi again started the conversion today it all started well ,but i have hit a problem with the gears got it all back together and i could not get it to go in to gear but it did go the one time in to first but had trouble getting it out then and i had to change the small cog which gos behind the clutch plate wheel for a smaller one any idea on this this many thanks

[@DaveSluggy]

+john doherty If you had to change the crank primary gear to match the clutch then you will need to corresponding 'big gear' that fits onto the gearbox input shaft - they must be a matching pair.

[@jackturner5890]

Hello I've got a issue with my 1987 honda economy c90, for some reason when I change gear from 1st to 2nd the front gear changer sits lower then it should causing me to slow down to wait for it to pop up and rarely slips from 2nd to 3rd, what's the issue?

[@DaveSluggy]

+jack turner Check the lever isn't rubbing against the footpeg bar, usually happens when the footage bar gets bent after dropping the bike. Other than that check the lever isn't slipping on the splines; if it is, and the splines have been damaged you may need to replace the shaft and that's quite a big job; although it can be done with the engine in the bike.

[@reggydunlop5770]

I imagine a ct70 is about the same?

[@billmcdougall8626]

Hi recently bought 1981 c90 and seams to be a bit clunky changing gears any ideas thanks.

[@DaveSluggy]

Start the bike, depress the gear lever and rev it up - if it tries to pull forwards then you have a real problem, if not then it's down to your gear changing technique. Best to adjust it correctly before anything else though.

[@skrrtmeep3594]

5:50 what’s that arm called I can’t find it anywhere I can’t find the name of it mine is bent and it won’t let me shift 😭

[@DaveSluggy]

That’s the clutch operating arm.

[@johndoherty8681]

hi there seen this vid very good had many of sleepless nights in doing this ,but can you say if it is easy to change the semi pit engine to a manual on the in side any info would be great thanks

[@DaveSluggy]

A fairly easy thing to do, you will need a manual clutch, the outer cover and the gearchange shaft; SS50 parts are far too rare and therefore pricey but plenty of Chinese pit bike versions around, especially after they loose 3rd gear ;-) Don't expect the manual version to be as good as a secondary clutch like the CBF or CG125 as this is a primary clutch spinning at engine speed.

[@johndoherty8681]

+DaveSluggy hi ,yer got the manual clutch and the outer cover ,and the gear shaft that i have came off a manual 110-125 pit engine which is the same as my engine which is semi auto so i will need to remove the gear shaft as well to do the conversion ? thanks

[@drumstyx]

Can you do a video on how the centrifugal part works. I'm racking my brain trying to figure it out but even with the whole assembly right in front of me, it just seems backwards. I haven't ridden this bike yet, as it's a rebuild project, so maybe once I feel how the clutch acts I'll understand better, but I just don't get it at this point...

[@DaveSluggy]

Depends on whether you have an early C50/70 clutch with the little roller weights or the later 12v type that has captive 'swinging' weights.

[@drumstyx]

DaveSluggy it's a 12v, and I can see the swinging weights, but I really couldn't mechanically understand it by looking at it. Perhaps it was the beers I love while I'm working in the garage though...

[@DaveSluggy]

If you look at the swinging weights they will bear against the rearmost steel plate (if the indentations it has made are deep then you can move the rear plate around by one notch and bring a new surface to the swinging weights. So when the clutch spins the bob weights apply pressure the this rearmost steel plate and as a result squeeze all the clutch plates together. That's why even when the clutch slips a lot when trying to kick start it doesn't slip when being ridden on the road.

[@tommytp85]

Fantastic videos. Thank you so much.

[@jackturner5890]

And it's not rubbing against the foot pegs

[@ericwerner9511]

Can you help please I just acquired a 72 c70 passport it was shifting rough I adjusted the clutch but now it will no go into neutral ..... please/thanks

[@DaveSluggy]

Are you sure you adjusted it correctly?

[@ericwerner9511]

DaveSluggy I adjusted it again seems a little better ....... workable

[@ericwerner9511]

DaveSluggy thanks

[@DavidT24Borg]

Hey ....nice vid good advice throughout 👍 I have a friend who has one in a kart and he can change up through the gears to 3rd and up again and it goes back into 1st....which is a problem .... have you any advice? Is there a mechanical stop ?

[@DaveSluggy]

There is a rotational stop that should prevent changing from 3rd up to neutral and through to first gear. It works on a drag link principal so will allow you to change from 3rd to neutral so long as you are not moving (think of stopping at the traffic lights in 3rd and then being able to go directly to neutral rather than needing to go down through 2nd and 1st. If you can change whilst moving then it's a fault but fixing requires complete strip down.

[@DavidT24Borg]

DaveSluggy thank you for your reply most appreciated👍

[@mikedld]

Thank you for doing this video !

[@vilno1044]

hi Dave, one question, i have a tao tao 110cc atv, how many shifts have this kind of atvs., because mine only has one, and what can i do to give more power and speed to this chinese atv? salutes and congrats from JUAREZ CITY neighboors of el Paso tx.

[@DaveSluggy]

I'll admit I've not seen one of these but they are generally all the same type of engine with one exception - they only have one gear and a centrifugal clutch. In order to get more out of it you would have to start by installing a proper gearbox and clutch before working on the top end for more power - sadly this is likely to cost more than a replacement motor.

[@TheBlabla1996]

nice!! doe you know how to adjust te nut at the end? mine keeps slipping when kicking

[@DaveSluggy]

Mitchell HürenKamp Adjustment is simple but often done incorrectly, you will need a 14mm ring spanner and a flat bladed screwdriver. Undo the locknut (14mm spanner) screw INWARDS the adjuster screw until it LIGHTLY contacts, UNSCREW 1/8 to 1/4 turn and tighten the locknut whilst holding the screwdriver firmly in position to stop the adjuster turning. Clutch slip when kick starting us usually a sign that someone has used Car oil rather than motorcycle oil and the friction modifiers cause the plates to slip. Replacement of the clutch disks and springs is usually the only permanent cure.

[@sierra2562]

is that the same clutch as the Honda CT 90

[@rashawnwhite4834]

On 7:28 what is that part called the black leaver

[@DaveSluggy]

thats my black handled nut spinner.....

[@luissantiago-hernandez9166]

Any idea where to find that black lever? Mine is bent and I can't find it. Thanks!

[@c501love4]

Nice work, you help me so much thx

[@adrianciprian6185]

Mi motor no venta no enclocha bien y le meti los disco nuevo.

[@markfs]

Dave, I was riding down the street on my honda ct110p and it was going fine. Then i stopped and it wouldnt go into first gear. I got the bike home using 2nd and the rest and it worked fine. But I cant put it into first. Any ideas? btw good video.

[@DaveSluggy]

Something has clearly gone wrong, could be the clutch adjustment - so try that first, if that doesn't work then you will have to open the casings and take a look inside.

[@markfs]

Thanks for reply. I will give it a go. The gear shift clicks like it is changing but it doesnt seem to be moving the transmission into first gear from neutral, and yet it shifts down from 4th to 3rd etc ok. Heel kicking the gears from neutral to 2nd to 3rd and to 4th works fine too. It didnt pop out of gear either.

[@Steve_Wardley_G6JEF]

Nice handy video, well presented but why is it like watching it through your letterbox

[@jimsager821]

Thank you

[@baheed46]

Can but thank you

[@paulrobb55]

would of missed a few of those pointers if i hadn't watched this video

[@NshsShdh-jx9ob]

👍🥰♥️👍👍

[@vaughnmaycock4504]

Fast forward to the next step after you tell us about what you are doing. Why make us watch every turn of every bolt ? Good otherwise !