Ace 90 Clutch issues

[jakecb420]

so, finally got my motor all back together again from a recent rebuild. originally a circlip broke and destroyed the top end. the bike ran and shifted fine before this. I put new bearings and seals in the bottom end and thanks to a true hodaka hero, mike p., I was able to get the top end into better than new condition. I had a slight hiccup with the small end connecting rod bushing but I think I got that licked too. I used a 12mm hand reamer and secured the rod in place and reamed it by hand but was very careful not to bind it up. after some fine tuning of the wrist pin with fine emery cloth it all slid together nicely. no more to end ticking noise that I had after initial start up.

however, the clutch issue remains. upon startup, everything seems fine.....that is until you ride it and then try to let the clutch lever out while in nuetral.....it just wants to go as though its in gear. also, it will not roll backwards with the clutch pulled in and in gear. I have been advised by a reliable source that it could be the clutch pinion bushing. I ordered one but apparently I ordered the wrong as the one I got was too big. I definitely plan to order the correct one tonite or tomorrow. since I had it apart today, I took the clutch assembly apart and cleaned the steel plates with emery cloth and soaked and cleaned the discs with kerosene and soft wired brush. I did this just to be sure that the plates weren't sticking. I put it all back together with suspected bad pinion bushing(measured 1.028 inches end to end) and decided to take out the .5 mm clutch adjuster and used a .2 clutch adjuster spacer and belray gearsaver fluid. also, I used a torque wrench to achieve 250 inch pounds on the pinion bushing. the bike behaves exactly the same.

is there anything else I should order while I am at it? I don't want to get spend crazy but I do want to make it work correctly.......hopefully this year!!!!

[Bullfrog]

I'm a bit stumped by the description of symptoms. It sounds like pulling in the clutch lever actually disengages the clutch - since you didn't describe any problems getting into 1st gear after starting and warming up the engine.

In which case, if you let out the clutch while in neutral . . . and the bike wants to go forward . . . it must not be in neutral, it must be in gear.

Then when you say it will not roll backwards with clutch pulled in and in gear . . . is that with engine running or engine off? Can you roll the machine forward with the engine off, clutch pulled and in gear?

Ed

[jakecb420]

I'll try and explain better. it can be kinda tricky for me to put it all into usable info. shifting into first gear is a hard shift and the bike immediately wants to go forward before I let out the clutch. shifts are a little harder than I remember from before I tore it down.

when I have the bike in what I believe is neutral(running) and I let out the clutch it wants to go forward, if I let the bike stall or shut it off, it rolls forward and backward no problem, all while the shifter in the same position(neutral).

It will not roll backwards with the clutch pulled in and in gear while running and while the engine is off. If I try and roll the machine forward with the clutch pulled in and in gear, the bike with resist to go forward.

I hope that helps explain things better(probably not!!) I think I am starting to confuse myself!

[jakecb420]

one more piece of the puzzle.....when I try to roll the bike backwards while its running and the clutch lever pulled in, I can see the kick starter move forward. I don't know what that means, just figured id throw that out there too. I have been asking myself if there was anyway I could have not put the kick starter assembly in correctly but I don't think there was a whole lot there to bugger up. it seems like that is one of the sympptoms of my problem and not necessarily the root of the problem.

[Bullfrog]

It sounds to me like your clutch is "dragging" (not fully releasing when the clutch lever is pulled in).

The first thing to check is the amount of freeplay at the clutch lever on the engine. Disconnect the clutch cable and measure the amount of freeplay available (measure at the outer end of the lever). Factory specification is 3/32". Having more than about 1/4" of freeplay could create a situation where you use up all the handlebar lever movement just "taking up" the freeplay . . . and never get to actually disengaging the clutch.

Ed

[rlkarren]

I thought I would chime in on this one at bring it up again because my Wombat is exhibiting the same behavior. (for clarity, clutch disengaged means that the clutch lever is pulled in, disengaging the transmission from power)

Engine off, in neutral and everything is as expected.
Engine off, in gear, clutch disengaged, I can feel a pronounced drag if I try to roll forward. Will not roll backward.
Engine on, in neutral and everything is as expected.
Engine on, shifting to 1st, clutch disengaged, a slight lurch forward. Will not roll backward.

It seems obvious to me that the clutch is not fully disengaging. Thanks for the clarification Ed. I understood the freeplay to mean that there needed to be 3/32" freeplay with the cable attached. 3/32" freeplay with the cable UNattached makes more sense and that would explain a few things on both my bikes...

However.. I'm wondering... since I already have three spacers installed, (they look like one of each size), is it typical or within the realm of possibility to have more than three? (My Ace 90 only has one, which I think is a .03mm).

At which point do you determine how many is too many or too much spacer? In an effort to answer my own question, if you use too many or too much spacer, the clutch will do just the opposite, not fully engage or slip. Am I correct?

Thanks!

Roger

[jakecb420]

yes roger, those are my symptoms also. i have not solved the problem yet. winter has stopped progress, but that's coming to an end. i am jonesing to throw some love at the ace. do you happen to notice any kick starter movement when moving the bike backwards?

@ed - I will measure my freeplay on the clutch lever on the engine again and report back with my findings.

also, on my list of things to do the clutch blue printing mod. not sure if that'll fix my problem but maybe ill catch it while its all apart.
i did install a new clutch pinion bushing a while back(no improvement)

[Bullfrog]

I don't "get" this description of "won't roll backwards". So do a test for me OK? With engine not running(off), watch the kick start lever very closely when trying to roll backwards. Any hints of movement of the kick start lever?

And the true test would be, after you have removed the clutch - will the machine roll backwards? If not, then it is time to split the cases to examine the kick shaft, kick rollers, kick roller retainer and the kick start gear.

ALL my bikes will roll backwards . . . and I'm still not sure what's up with that reported symptom.

[rlkarren]

Won't roll backwards means literally that... will not roll backwards... it feels like binding gears. And yes, the kick start lever rotates forward when trying to roll the bike backwards, with engine on and off, in gear... my first thought was that the kickstart mechanism was somehow binding... I resigned myself that I would have to split the cases again but when I took the clutch off, everything moved freely in and out of gear. To me, this eliminated the kicktart mechanism as the culprit and revealed that it has something to do with the clutch. I tried a different clutch, pressure piece, less spacers, all the spacers... I even disassembled the clutch pack thinking the disks were sticking. The only time I saw improvement was when I used all the spacers, (.2mm, .3mm, and .5mm).

With that in mind, I am almost convinced it's because I need more spacers. Got some more on the way. And besides, if it's supposed to 3/32" freeplay with cable unattached, I definitely need at least one more spacer.

What I think is happening is that the clutch is not fully disengaging. Without the the proper spacing, the clutch lever on the engine has a very short throw, causing the clutch to mostly, but not completely disengage, leaving just enough drag on it so that it forces the kick start mechanism to lock in all the time.

Anyway, I'll know for sure in a couple days... I was just wondering if spacers the equivalent of 1mm - 1.5 mm, or even more, is excessive?

Thanks

Roger

[michael_perrett]

I would not worry about a defective kick starter system yet. Rolling the bike backwards with a dragging clutch will just reverse the effect of the kick retainer and rollers. Think of the kick starter gear as the beginning of the starting sequence, trying to move the kick start lever. It will engage. When all items in the engine were new, no problem with clutch drag and therefore no problem with the kick starter movement during a " back up with transmission engaged" test. Ed Chestnut's clutch blue printing work will eliminate the drag issue. (After a new pinion bushing, properly torqued is installed).
Still meditating in the Center
Mike Perrett

[Pep]

I dug through some notes that helped me understand Hodaka clutch concepts, and here they are. Don't know who to credit on the first page, but the second page (with part photos) I believe came from Ed.
Hope this helps.
Laurie

[BrianZ]

One more thing to consider. The thickness (amount) of shims required to properly adjust the clutch freeplay is also dependant on the thickness of the clutch cover gasket. Installing a thicker gasket moves the clutch actuator further away from the clutch, thus requiring more clutch shims to take up the space. So installing a new gasket, especially from a different manufacturer, may throw the clutch freeplay out of spec.

Brian

[Bullfrog]

I've experienced dragging clutches before . . . but have never noticed the "won't roll backwards" symptom. I'd have to say that it seems like there must be a problem with the kick start system in Roger's engine. However, it certainly makes sense to get the clutch working properly to see if that strange symptom goes away . . . before tearing into the innards of the engine/transmission.

NOTE: New (un-worn, therefore thicker) clutch friction disks will "move" the outer end of the clutch assembly toward the center of the engine . . . and a thicker clutch cover gasket will "move" the whole clutch cover away from the center of the engine. These two factors could require quite a few shims to properly adjust the lever freeplay at the engine - and that is OK.

NOTE: It can be argued (quite properly), that The Workshop Manual specification of 3/32" of lever freeplay (at the engine) may have been developed to ASSURE complete clutch release, while (somewhat) ignoring the possibility of that clutch friction disk wear during a single race or difficult (clutch abusing) trail ride could be enough to allow the outer end of the clutch assembly to move away from the engine center line enough that ALL lever freeplay gets used up (and then some). This could result in a situation where the clutch never fully engages (slips). For trail riders, this situation would be rare. For gung-ho, clutch fanning racers . . . it is not that rare. Setting up freeplay at 1/4" has proven effective for the racers . . . without creating a dragging clutch situation -- with a properly built, maintained, blue-printed clutch that is. (A certain racer I know sets up his freeplay at 3/8" inch . . . I just can't go that far . . . yet.)

Ed

[rlkarren]

well.. the spacers arrived and I installed enough to provide the correct freeplay. still didn't fix it. grr...

Anyway.. I resigned to splitting the case, and found the problem of the missing kick start thrust washer... Preliminary tests show that this solved the issue. I had a raging headache last night and still need complete reassembly to start it up. But, I was able to get it to the point I could disengage the clutch and roll it forward and backward while in gear without binding.

Feeling a bit sheepish, but still grateful for your help. I'll confirm issue solved when I complete reassembly later this afternoon.

Jake, it looks like a case splitting is in your future... I suspect one of your kick start thrust washers is missing or incorrectly installed.

Roger

[rlkarren]

Well.. that was the problem... a missing kick start thrust washer. Actually it was in the wrong place, somehow I had installed it UNDER the roller retainer which effectively was the same as a missing thrust washer.

Thanks for everyone's replies. but now I can actually ride! just in time for the weekend.

Roger