Forza stutter at take off but also a bit after take off

[Austins]

So I have a Forza 2016 with 8500km and I'm in Thailand - this might be important as it gets really hot here, specially in traffic... !


I had this issue with some other CVT bikes, stutter of clutch at take off, and some friends say it maybe due to my riding habit, but funny enough I take off almost full throttle from most traffic lights as oppose to people saying this happens because riders start off slow and with hesitation !

Anyway, I read a lot about it, the take off stutter is usually due to glazing of the clutch shoe and housing, most people know that and clean it up etc. - although it comes back after a while. I heard they say this is due to OEM clutch shoes not being of high quality etc. and have resin in it that melt at very high temperatures (but I am no expert in that stuff).

But I am writing this post because I have a little more issue than take off. As you might have heard you can hold the breaks and give the throttle a quick wack for a couple of seconds. This helps to de-glaze a bit (not too many seconds as you can damage it), it is temporary solution of course. So after I do that then the take off from 0km to say 10km is fairly smooth for a while if you take off slowly, you can feel the clutch engages and the bike moves forward okay.

But here is the problem, from 10km to 20km if I try to carry on slowly, I get a terrible stutter, rattling noise and almost vibration of the bike... !? This is the bit I don't understand, if the clutch has already engaged, then what is this all about. I read somewhere that they say maybe the clutch dis-engages and re-engages again and hence all this stutter and noise. But why... !? It wasn't like this when I got the bike last year, and I amazed it so quickly developed this issue (my other scooter had this after 30,000km).

I don't have the tool to open it myself and first Honda dealer so far said it's not a big deal and it's okay, you can change all the parts but you get the same issue coming back again, I have done it and know this ... !? I think he is just busy and does not want to do a time-consuming low cost job of open, inspect and clean. I am going to another dealer soon, but here in Thailand, it is hard to speak with these mechanics in English, and they are not prepared to discuss anything, just my way, or well, no other way... !

Also here they just want to quickly change parts, rather than repair or clean etc. so I wondered if I have more info it will be useful when it is opened to avoid unnecessary costs.

So far I know I need to ask them to check any deformity on variator plates, roller flat spots, clutch/bell glazing, and generally clean everything, anything else... !?

[mymitzi]

Near 17,000 miles on my Forza and have the "judder" issue not at take off but "in between" disengage/engage. Still think its the clutch pads
needing cleaning. Hope to get around to it. Probably worth it for you to get the proper tools to check for your self. Does seem strange for
[my case].....that there is no judder from take off. Possibly the the clutch shoe springs are weak/inconsistent?? Still riding though..try to avoid
that "in between" transition. Almost seems the clutch springs aren't fully releasing while coasting at speeds you mentioned. Good cleaning ....
more than likely will fix it. You will probably get yours done before me.....unless I stop procrastinating : ) Please come back after the fix and
let us know how it worked out. Mine is [2014 Forza]

[Austins]

Yes, I go in the next few days. What concerned me a bit was all the noises, sounds like something is loose or rattling, good point about small shoe springs, there is of course the big one too. I bet the dealer mechanics will want to change all of these, even a full clutch, but probably just one of these things are the cause ...

Will report back...

[davenowherejones]

My Forza clutch bearing broke a long time ago. It makes a lot of noises. One guy asked if I had a diesel engine.

[Austins]

Yes, need to check no issues with bearings and it turns smoothly and as it should. But the noise for that will be usually more at high speed I think, but worth checking...

[davenowherejones]

Yes, need to check no issues with bearings and it turns smoothly and as it should. But the noise for that will be usually more at high speed I think, but worth checking...

Actually at high speed the clutch is locked up and there is no noise. The big noise is at idle when everything is shaking loose.

[Gil]

One of our members from Thailand fix the issue with some local, to him, aftermarket clutch Bell and shoes for his pcx. The bell had some groves into the clutch contact area. He said that it fixed it on his pcx. Might be the same with the Forza?

[gn2]

But here is the problem, from 10km to 20km if I try to carry on slowly, I get a terrible stutter, rattling noise and almost vibration of the bike... !? This is the bit I don't understand, if the clutch has already engaged, then what is this all about. I read somewhere that they say maybe the clutch dis-engages and re-engages again and hence all this stutter and noise. But why... !?

Why is because of how the clutch works.
The clutch is centrifugal.
What this means is that when you apply throttle increasing the rpm the clutch shoes are thrown out onto the bell by centrifugal force.
In order for the shoes to stay in contact with the bell there must be enough centrifugal force to keep them there.
As speed reduces the centrifugal force reduces and there comes a speed at which the clutch will disengage, on my Forza 300 with completely standard drivetrain I think it was about 10-12mph or so.
So the reason for the judder at slow speed is the same as for when moving off, clutch judder from glazed/damaged/incorrect shoes or a distorted heat damaged bell.
Always use guaranteed genuine Honda parts, there are plenty fakes about, also don't get conned into buying sub-standard "performance" parts from dodgy sources.

[alx123]

One of our members from Thailand fix the issue with some local, to him, aftermarket clutch Bell and shoes for his pcx. The bell had some groves into the clutch contact area. He said that it fixed it on his pcx. Might be the same with the Forza?

That was me, 2 years with the same clutch and never had any problems anymore. Smooth take off, no shudder hesitation or any feeling of clutch slipping.

TS, since your in Thailand, buy something like this https://www.lazada.co.th/products/forza ... gJazPD_BwE

OR

If your'e in Bangkok, i can help you find a mechanic that specializes in PCx and Forzas and is very familliar with this problem. Forget Honda dealers, theyre really inutile here..

[Austins]

Thanks for the info, I'm in Phuket though, it's a shame because if Honda mechanics ask me to wait inside and not able to look at what they open and check for myself I won't be happy, some of the guys working here in authorised dealers are a joke, not qualified to repair a bicycle, let alone a modern motorbike (as you well know how it is in Thailand)... I'm always amazed Honda manages to get them build such machines here...!!!

[Austins]

Actually at high speed the clutch is locked up and there is no noise. The big noise is at idle when everything is shaking loose.

Okay, I am not sure where that clutch bearing is then, I try to see if I can find it once they opened it and then check it, I kind of understand what you are saying but can't quite visualise it and know where it is...

[alx123]

My best guess is that you'll only need to change the clutch pad to a much better quality and nothing else.

That's what I did to my PCx, and never had that issue again. But then again, you own a Forza so it might be a different case.

I would suggest buy the pads online, bring it to a shop, and tell them you want to install it. Changing clutch pads is an easy job, any shop should be able to do it in a few minutes.

I don't trust any shops here in LOS, that's why I started to do my own maintenance. Good shops are so rare that once you find one your'e lucky.

[Austins]

Just a quick question, does the big clutch spring have any effect on clutch shoe engagement...!?

As I understand it the yellow 1500rpm or red 2000rpm that offered by the likes of Malossi only push against the drive plates at the back end, they prevent it to open easily, so it opens later at higher rpm. But have no effect on shoes centrifuge operation, correct...?

[you you]

Just a quick question, does the big clutch spring have any effect on clutch shoe engagement...!?

As I understand it the yellow 1500rpm or red 2000rpm that offered by the likes of Malossi only push against the drive plates at the back end, they prevent it to open easily, so it opens later at higher rpm. But have no effect on shoes centrifuge operation, correct...?

That’s my understanding.

[Austins]

Just to report back that I went to big Honda service shop in Phuket Town in Thailand yesterday, there was a mechanic who speak some English, my Thai is limited to a few words really... But he was so condescending and joking, and tried to avoid doing just about anything I asked. But at least I could stand by him while he opened the CVT. He said it takes two hours work, but he wrapped it up in less than 1 hour and most of that was waiting for it to cool a bit...

When I mentioned the problem and said why it happens at 8600km, he immediately said are you the original owner, I said 2nd, then he joked, ah, then your km counter was reset, which did raise doubt and upset me, but I pointed him to original oem tires with dates on both and the fact that they were still not even half worned. He went quiet a bit after that...!

Also my doubts disappeared when he opened the CVT box, everything was almost brand new, I couldnt believe it, I forgot to take photos, but I have seen inside of a few CVT, and nothing so new..., not much dust or dirt either, very little, rollers perfect, I asked if variator plates are okay, he said, No, of course joking I think, as I asked too many questions, I run my fingers on the very smooth surface, and said what is wrong, then he laughed and went quiet, very annoying guy...!!!

Anyway, the only obvious thing was the blue color around clutch bell housing central part, due to heat I guess, I did hold the breakd and turned the throttle a few times to deglaze...but once opened inside was very smooth and no issue, the clutch shoes were the only problem, you could see the glaze, the only think I managed to get him to do was use the 80 sandpaper I bought to clean it (I read here someone recommended it), it was hard to get him do that, as he wanted to use his crappy old sandpaper...!

He didn't open the clutch but I really couldn't see anything wrong as the whole thing was like brand new, no sign of black grease or dirt, even some grease I saw was kind of without colour or greyish....

Now I asked him to open and clean air filter and he says no, not sure if he blasted air in the clutch box filter, but he did blasts air in variator and all CVT, didn't open the clutch further to see the springs, but lifted the shoes with screw driver to show me its okay. He put it back together but no grease, not sure, is it needed !? , maybe there was enough there...?

Anyway, the start is smooth now, I think 95% fixed, and maybe I'm just picky and that is how it was when I got the bike...all that rattle, noise and judder for this !

No idea how long it would last, I think shoes had about 2/3 left, but if it starts stuttering again, I definitely buy those carbon aftermarket shoes...

I don't know how Honda fails to mention this anywhere, that you need to open and sandpaper your clutch shoes as maintenance and frequently, like 7000km when it all started on mine ... !!!? Because we can't put quality shoes that even lasts to your first service period of 12k...!

[alx123]

That's what a typical Honda dealer mechanic in Thailand is, never want to do anything that the customer requested.

It's so frustrating that Iv'e had enough and quit using their service after a few times.

Sanding will definitely fix the slipping clutch issue for a while.

[mymitzi]

Appreciate the report.............Thanks Austin...... [waiting for the weather etc. etc. etc.]

[Austins]

I forgot to mention this white stuff on the cover of CVT on mine and I can see it on many YouTube videos too - see photo below (this is not my bike I copied it).

Not sure, but I guess it is due humidity or water hitting that area when it is hot, I rarely ride in the rain and my bike never submerged in water up to there, but I have exactly the same thing on my CVT cover... Any idea

[mymitzi]

There is an insulating material inside the black cover that deteriorates over time ,shedding to the metal cover. Same on mine. Don't think its
a problem.

[gn2]

The white stuff is corrosion.
Best to leave it in place as it prevents any further corrosion.