Modern Vespa

Thought I would create this post, to document what I discover about my HiT Clutch from Dr Pulley, paired with my 13g Dr Pulley Slider weights.

I've got it ordered and should get it this week.

I'm going to get the clutch pre-setup with the correct type of pillow and clutch springs as per the document (201203 Nextd. clutch RRef.doc) posted by Dr Pulley (paul@unionmaterial.com) in this post: Clutch with the J. Costa?

UPDATE: Do not use the configuration recommended by Union Material for a MP3250ie. It resulted in poor performance, and a potential spring shear in the clutch. Read later post for more info, including symptoms.

I got my clutch by first checking this document, which details what clutch for what scooter:

http://www.unionmaterial.com/HiTClutchType.pdf

The key to selecting the correct HiT clutch kit is the Clutch Bell diameter, specified in the document for you to match with your OEM Clutch Bell.

I am looking for as close to OEM as possible, so I can eliminate the "Strangled Sealion" and get a little bit more peppy performance. But not so much that I loose the ability to do inner-city riding in peak hour.

So when I have got the clutch installed, I'll post my findings.

I believe larry8 has the HiT Clutch installed as well, so it would be interesting to hear what he thinks as well.

I'm looking forward to hearing...er....reading the results.

-nub

I did buy the HiT clutch set up by Union to emulate the stock clutch as close as possible. However I didn't install it yet - was going to install it in July, but didn't have the time on a rainy day to do it. Good riding days up north here are precious and I don't want to use those days to do work on the scoot, much rather ride. So, I'm planning to install it on the next rainy day.

No worries larry8. I can understand that you want to save your riding days for riding, not spanner time.

Perhaps I might have it installed before you.

Hopefully it will turn up this week for me.

Generally, I try to do all my mods and maintenance work in the winter months unless something breaks or fails. The only thing I plan to do in the good riding months is change the oil.

UPDATE.

Original Australian supplier couldn't supply me with the clutch after all, so I got my money refunded and went with scootertrap instead.

The difference in the total cost for the item and shipping was about AUD$15 (after the exchange rate and international freight). Should have just gone with scootertrap to start with

Depending on how long it takes to get the clutch in, and shipped to Australia, I'm hoping to have this installed by the end of August '09.

Hopefully I'll have this done as part of the Scooter Servicing night that is happening at my local dealer. I've put my name down for a free service on the night

Looking forward to posting my results soon.

I agree!! Your clutch is on the way my friend!! Enjoy!

Matt C.

Wow! Lightning fast special ordering, manfetti!

I just hope it doesn't get delivered while we're over in New Zealand next week . From past experience, it usually takes at least 7 working days for it to arrive from the US, so we should be right.

It might even show up by Tuesday next week (Wednesday is a public holiday, with no mail service)

Looking forward to a shiny new clutch package waiting for me when we return from my 30th Birthday, and 1st Wedding Anniversary (belated) celebrations.

Clutch has arrived, and I am having it installed tomorrow (Friday). Springs are mighty hard to swap out. Will have to get the dealer to unhook the installed pillow springs and install the correct ones.

Keeping the OEM clutch bell for the time being, because I mistakenly thought that the clutch kit included the bell. Hopefully the workshop will be able to remove enough of the blueing to revert the bell to *nearly* brand new. With the new clutch installed, I'm hoping my experiment will prevent or significantly reduce clutch slip.

NOTE: For those considering this mod, heed the following advice:

If you want to get the clutch and a new bell, you must order them as separate items. That also includes the contra spring and washers which I will also be keeping as OEM due to the same reasons. Hopefully they will be OK and will be able to cope with the extra power.

I was looking at a GY6 package, that had everything included, but it looks like this is a special package put together. It is not the norm.

Will post initial results tomorrow after picking up the bike.

So the clutch is in and I have road tested it over the last few days.

Setup for the road test is as follows:

Clutch Shoe Spring: 18KG
Pillow Spring: 20KG

Observations (rider only):

After riding it home from workshop.

Shuddering from start off due to the clutch biting the bell HARD. For those who have experienced the Strangled Sealion, it is kind of like that jerking motion, except much more violent. It feels like someone is kicking the scooter.

Observations (rider and pillion load).

Before clutch was installed, the engine note was rev high > dip to medium revs > up high and begin to move off (with much clutch spinning).

Now what happens is that under pillion load, the scoot revs high > dips slightly > then revs from med-low to high revs. Think of a go kart direct drive engine after it has been given a push-start.

We did a slight hill start, and the behaviour in the previous paragraph was observed.

Under pillion load, the bike noticeably kicks when it takes off. With my load only, the bike kicks a few times then levels out.

Observations (today).

Started off in the morning for work and accelerated like I usually would. The bike stalled immediately!!!

"Oh-oh" I thought! Am I even going to be able to ride it out of my unit complex???

Restarted and didn't apply as much throttle. The bike was struggling noticeably to move away at first but didn't stall. I rode it down the driveway and up the back laneway. The problem started to disappear after about 2 minutes, and the bike began to behave like it did the day I picked it up.

Seems that from a cold engine start, the engine and drivetrain can't take the load that the clutch puts on the drivetrain.

Feelings/Hunches/Guesses

I think the pillow springs seem to be the critical element in the behaviour of the clutch. If you want the pillow to engage earlier, you put on a heavier spring. I'd be grateful if someone could clear this up for me though.

News Flash

I don't know if it was the spring configuration, but all three 20kg clutch springs failed in exactly the same place (AFAIK). After about 1000KM!!!

I strongly believe that the springs included in my HiT clutch kit suffered from a manufacturing defect, where the springs were not correctly tempered by the manufacturer.

Pre-cursor Symptoms

I noticed some binding in the clutch when manually spinning the rear wheel.

Rough take off, including jarring and engine labouring.

Stalling, as the condition worsened. Bike would snuff in traffic, and I had to hope it would restart without snuffing again.

Diagnosis

Basically, the springs were failing one by one which explained the progressively worsening symptoms. When i took it to the dealer for investigation, he was alarmed to report that there was only one (broken) spring remaining in the clutch. The rest were somewhere across greater Brisbane...

The springs were failing at the bend of the first turn of one end of the spring. Just where the neck of the spring bends into the first coil. Totally sheared off!!!

New Configuration

I had the tech install a 24kg set of clutch springs. The pillow springs remain at 19kg.

Initial Performance Observations

Acceleration is far, far smoother. No harsh jarring when you take off.

Improved Acceleration and Re-acceleration, because the springs don't engage as quickly as the 20kg springs.

Pillion riding is the same, if not slightly better than what I remember. This is somewhat subjective, because the behaviour of the bike on hills was probably caused by the clutch not disengaging at low RPMs.

No loss in hill climbing ability.

No more stalling.

Best Guesses about Performance

I think what is happening now is that the pillow springs are engaging before the clutch springs, which is putting an even pressure on the clutch shoes as they meet the clutch bell, rather than after the shoes meet the bell. This results in a smoother, more consistent clutch engage.

Hi,

Following pictures & clutch-in data about HiT201203 ( fit for Piaggio's 125 to 300 CVT vehicles) is just for reference.

My clutch shipped today - a different model. Paul said, "HiT251701 can fit any Piaggio group's 400/500 CVT scooter or ATV." He sent 3 documents for the clutch. If anyone is interested, contact me with your email address and I will send them. HERE IS THE INFO OF ONE DOCUMENT:

Test steps of HiT clutch and Sliding Roller Weight
The pillow spring/clutch spring installed in the HiT & its clutch-in rpm is showes as in the Clutch-in data Table as enclosed.
To compare the performance of SR & HiT clutch with the STOCK ONE ,it's better to test the parts as following steps:

1. SR vs stock round roller-------under the STOCK CLUTCH ,replacing the stock
roller with the SR , comparing different weight of each SR you have to see which one is better to the vehicle.

2. HiT clutch vs stock clutch------choosing one SR & installing the HiT clutch as it comes out the package ( ie, no need to change the springs ) to see how is the
performance.

a) HiT clutch is ok --- means the vehicle is smooth and powerful at taking-off and the capability of overtaking & hillclimbing is excellent.

b) vibration at take-off but the re-acceleration is powerful--- means the clutch
engagement is too strong or the vehicle is too weak to drive the
solid engaged HiT clutch/clutch outer from the standstill. Please
replace the clutch spring with harder one or replace the pillow
spring with the harder one or replace both spring with harder one.

c) no vibration at take-off and re-acceleration is poor too--- means the v-belt might be slip (ie.the clamp force of V-belt is too weak, you'll find the surface temp. of variator is much higher than that of clutch outer. ) It's better to use heavier SRand torque spring washer to clamp the v-belt tighter.

d) if you want to try different pillow spring or clutch spring to see different
performance at different combinations of Pillow/ Clutch springs. Please see the
HiT instruction enclosed in the package. And always choosing the clutch spring
first for the correct engaged rpm and then select the pillow springs.
If you have any problem about the parts,please contact us via
e-mail: unionltd@ms14.hinet.net.

IF ANYONE DESIRES THE OTHER DOCUMENTS send me a personal message with your email and I will send them. There is one Word and another Acrobat.

It's been a while since updating this post, but I've had a lot more KM's under my belt now with the HiT fitted on my 250.

I must say I've had variable results with the clutch. Some positive. Some negative.

Originally I was quite impressed with the performance of the clutch. Over time, the clutch action has got more and more "aggressive", which for me is undesirable.

By that I mean that when you punch the throttle the bike "kicks" and the RPMs drop significantly. It also results in tyre squeel in certain situations. This is using the default, recommended configuration from Union Materials (19KG clutch and 20KG Pillow). This configuration is supposed to give the balance between performance and ride comfort.

Because my scooter dealership fitted clutch springs instead of pillow springs, the pillow springs (which were clutch springs) failed very quickly and led to this "kick" behaviour because the clutch was engaging too hard too soon.

NOTE: The clutch springs are *shorter* than the pillow springs. Be very careful to install the correct spring when servicing the clutch or experimenting with different engage settings.

I have to say that it probably isn't the clutch causing the problem now. I have a feeling that other components are glazed in the CVT and this is causing the "kicking". The Bell had a mirror finish when I removed it recently. I've noticed that my front and rear variator halves are 'cloudy' now. Don't know if that is how they should be. When I pass a pointed object over them, it reveals a shiny surface below. I can also see that my OEM belt has a shiny finish on the contact points. Should it have this?

I'm at the point now that I really don't know what to do regarding the HiT. Here are my perceived options:
* Leave it in and bear with the kicking and lack of ride comfort.
* Return the clutch to stock and bear with the "Strangled Sealion"
* Get a polini "heat transfer" clutch bell with heat sinks and engineered ventilation.
* Put in a performance kevlar belt and revert to stock clutch.

(my scooter dealership had techs that swear by the malossi/polini kevlars - they have them installed on their own scoots with excellent reliability).

Just curious, you mentioned in the beginning of the thread that you were installing heavier Dr. Pulley sliders. Do you have a comment on them? I have been thinking of installing them, but closer to the stock wt. (11g).

Yep, Dr Pulley sliders are awesome. The simplest and cheapest way to get extra performance without significant expense. But I would suggest installing heavier rather than matching the weight (i've got 13g sliders installed into a stock variator).

My mechanic's experience suggests that always put slightly heavier Dr Pulley sliders in because they don't roll, they slide. The friction part makes it necessary to use heavier weights. This mechanic also has Dr Pulleys installed (in fact, pretty much entirely Dr Pulley drivetrain).

YMMV.

Also bear in mind that if you change one thing, you will invariably have to balance it out somewhere else. Messing with the base OEM configuration is, from experience, acknowledgement that you will be spending more money than you care to on tweaking.

Just saying...

AYYYYMEN, Brother!!

That's why this forum is so great for info on things from guys like you, fuzzy, luthorhuss, etc. that have gone before and played with their scoots, making it a bit easier for the rest of us. Thanks much!

Could you tell me what's the clutch spring, pillow spring installed in the HiT ? and if it's available please post a photo of your HiT clutch so i can
know more.
By the way did you tell your seller this problem ?

It was the default configuration you sent back to me when I returned the clutch to Union Materials.

Blue clutch shoe springs. Yellow pillow springs.

What I've done now is remove the HiT clutch and the Dr Pulley 13gm weights, reinstalled the stock clutch, put in standard stock 11.6gm rollers, a Malossi X Kevlar, and a Polini Evolution 2 vented clutch bell.

I have over 500km of stress-free, consistent ride quality. No issues with kicking, or stalling. No problems with clutch bell vibration.

For me it is all about reliability now. I don't want to be forking over $75 to tweak the clutch every time it starts to cause operational issues. I've invested enough time and money in this experiment now that it is easier and more cost effective to sell the performance parts and hopefully someone else will have some luck with it.

Fortunately, I don't know so much as you guys so I installed my HIT clutch as it came with my J COSTA and it has worked beautifully for about 3 months now. Everything is very smooth. My Vespa mechanic rode it and was very impressed. I have heard a little knowledge is a dangerous thing. In this case I think no knowledge is a wonderful thing.

I think it's going to be different on the more powerful 500cc engine than the 250cc engine.

Hi Jaredmorgs,
in your last post you said" It was the default configuration you sent back to me when I returned the clutch to Union Materials. " -- do you mean you send the HiT to Union Material? and to whom ?

Here're videos about the HiT201203 in BV250

Paul Wu at Union Materials. He was very helpful, but the clutch configuration still didn't solve my problem.

Hi,

So you're Jared!
Sorry,the previous HiT doesn't solve your problem.
If you could pay 95.00 of shipping cost via DHL ,i'll send you one new
HiT201203, what do you think?

Jared, I am curious with regard to the sliders. Why remove them as well, as they did not seem (at least to my reading) to be the root cause of your issues? Were they 21-17s?

No they were 20-17s.

They were not the root cause, but I think they were a contributing factor. They made the engine rev higher (and the stock clutch spin more) on takeoff up hills. They contributed to my decision to buy the HiT clutch to start with, which then caused further CVT config issues.

With the 13gm weights installed and the HiT clutch biting too hard, it was easier to remove the weights and clutch at the same time and revert everything back to stock. And I have to say that decision was a sound one.

It's like when you are tring to work out what is wrong with your Home Theatre setup and you have too many different things that *could* be causing the issue. Go back to the simplest config you can and then add things in gradually.

In this case, I'm quite happy with how the CVT behaves with mostly stock components in.

For me it is a tradeoff. Snappy off the line performance, or predictable reliability. Stock gives you the latter.

I have had pretty much the same result as Jared while using the HiT clutch. I think the 12 or 13 gram rollers (I used both and they were the 21 17 size) cannot hold the ramp plate against the belt firm enough to prevent slipping when the HiT is holding on so tight in the back. I get slippage up to about 10 mph and then all is fine, if I accerelate slowly I don't get much slippage if any but that kind of defeats the point of the HiT no? I currently have the black clutch springs and the yellow pillow springs in the clutch and I will get a 55 mm socket so that I can take the clutch apart myself and not spend money on the mechanic while experimenting.

BTW I never had the "strangled sea lion" sound that Jared had on his scoot, I just thought a new clutch at 18000 miles was a good idea. The old clutch is still good though and I can always go back to that.

Just got done ordering this

http://www.amazon.com/Sunex-455M-Standard-Metric-Impact/dp/B000SOU8IW/ref=sr_1_18?s=gateway&ie=UTF8&qid=1285374473&sr=8-18

55mm impact socket for $10, lets hope it is up to the task.

Hi,
Did you see my post on Thu Sep 23, 2010 6:29 am ?
The HiT installed in the BV250 is same as yours -- Spec of HiT201203 :
pillow degree 55,
clutch spring SCJ 1828007100-BK-14kg,
pillow spring SP2032365103-YL-20kg

You say the HiT will be slippery until the speed is reaching or higher than 10mph,i don't understand why " slippage before 10 mph " is a problem ?

As i know each clutch must have a suitable time or period of slippage that means 1) not too much to prevent the power loss and fade of clutch bell
2) not too less otherwise the engagement will be too abruptly.
If the HiT is installed with a harder clutch spring and no pillow spring (ie.without pillow spring ), the HiT will grab the clutch bell suddenly.the vehicle might be wheelie.
please see the attachment to see if my explanation is clear .

I did see that post but I'm thinking that a BV-250 is lighter than a MP-3 250 and so the belt is under less force to get traction on the variator or the clutch. Slipping is not noticable when using the stock setup so why should the HiT clutch cause it? I cannot describe the performance of the bike under these conditions, you really need to find a MP-3 250 nearby and test it out for yourself. It isn't a question of the vehicle wheeling, it is an issue of the vehicle not moving away from a stop in a timely manner. All I can say is that the performance of the HiT clutch as delivered and installed onto a MP-3 250 with 13gr Dr Pully silders is less than when a stock clutch is installed. Try it if you can.

HI All,

I own a Gilera Runner 200.
Lately I installed the HIT clutch in it, 40 degrees.
I was really impressed at the first drive, I couldn't believe how much slippage the stock clutch had.
After some tuning for my style of riding I got even better results, strong take off and strong re-acceleration for over taking.
All of this at pretty much the same rpm like the stock one.
I want to try another set of pillow springs in order to get a little bit higher engagement action.
Paul was very helpful in technical support.
Also got the SR sliders and really like them.
Just wanted to share from my experience.

Thanks,
Roei

I'm glad it wasn't just me who experienced problems with this setup. I was starting to think my issues were an edge case.

Hi Zinfan,
Thanks.
Your question of " Slipping is not noticable when using the stock setup so why should the HiT clutch cause it? " --- my opinion is the grab force of stock clutch is not very strong at low rev and the clutch slippage might be existed so the clamp force of v-belt is acceptable. For HiT,its grab force is much higher and clutch slippage is much less so the SLIPPAGE might be happened at variator if clamp force of V-belt is not high enough ",what do you think?

I have found a MP3 250 in Taiwan,I'll install the HiT and see what's the result.

Make sure you install the hit with 13gm slider weights as well. You could also experiment with blue clutch springs and yellow pillow springs. This is how you sent the clutch back to me when I sent it back to Union Materials for investigation.

Might be able to get the perfect balance for both Zinfan and me.

I've found that with the stock clutch, stock variator weights, and a Malossi kevlar X v-belt, the RPMs still drop quite low on takeoff. So I think because the HiT clutch tends to grip hard on takeoff the natural nature of the QUASAR transmission is just intensified by the power of the HiT.

Hi,
i'll try different combination of springs, RR, SR but the HiT is only same as Zinfan's .

Dr. Pulley, if it would help any, my husband speaks/reads fluent Mandarin. (He's Mainlander) While your English is GREAT, you may want to get more detailed and might not know how best to say it. Just post in Chinese and I'll have Yi (husband) translate it for you, if you ever need it.

Hi,

Thanks so much.

Hi jaredmorgs
The test of HiT201203 ( see the picture attached in previous post on Tue Dec 22, 2009 1:32 pm) in MP3 250 is done, as below.
Test1;
HiT201203,its spec
pillow degree 55
clutch spring --SCJ 1828007100-BK-14kg
pillow spring--SP-2031365104-PK-25KG
Original roller 2117 11.2 gram
Test2;
HiT201203,its spec
pillow degree 55
clutch spring --SCJ 1828007100-BK-14kg
pillow spring--SP-2031365104-PK-25KG
Dr.Pulley SR2117 in 13 gram

The rider told me the acceleration is much better and there're no noticeable shuddering for both tests.
Since I don't have much sense about the scooter so I can not test the riding myself.
Anyway I hope you can see something (positive or negative ) from the videos in youtube,

I installed the Dr. Pulley 12 gram roller/sliders plus added a second stock washer and I am impressed and how much smoother it is from the rollers and even better take off because of the washer.

Hi Zinfan,

Following videos is about the testing of HiT201203 with different pillow degree in MP3 250, (two riders.)
The rider says there's no any noticeable shuddering at take-off in WOT from standstill.