I've got a Power Bloc clutch for my FL250. I am trying to decide how many weights to leave in each puck for a first attempt. I know that I can just keep experimenting, but if I've got to lift the Engine each time to remove the clutch bolt, then I'd rather start off aiming somewhere close to where I need to be.

Any of you guys with Power Bloc clutches have any guesstimates on RPM engagement per # of weights. I think I've got 4 weights/discs in each puck right now. Sort of what I'm looking for is the following:

4 weights/puck = ___________ RPM
3 weights/puck = ___________ RPM
2 weights/puck = ___________ RPM
1 weights/puck = ___________ RPM
0 weights/puck = ___________ RPM

I'm just trying to get a ballpark here to know where to start. As you probably know, with the stock FL250 clutch, take off feels like starting off in 2nd gear.

Thanks for any input you might have. Even if you have an FL350 or FL400 Power Bloc, I'd still be interested in hearing how each # of weights affects engagement RPM. Please just let me know what you have (FL250, FL350, or FL400) when giving RPM estimates.

Thanks again,

Rhinoguy

What spring do you have?

I think it's the standard spring that comes with the Power Bloc FL250. I looked and couldn't see any color markings on the spring. In terms of color, the spring just has a typical heated treated look. I'll attach a couple pictures.

Also, are there supposed to be any washers inside the Power Bloc clutch assembly?

The only washers mine has are on the clutch cover. One large original washer (that seems to be low grade soft), and I added a Grade 8 washer on top of it.

Just trying to make sure that I am not missing any internal washers/spacers. Most of all, I hope to get a ballpark figure on engagement RPM's that I can expect with different weight combination's.

Rhinoguy

i will ask Kyle he use to race 250's and used a PB clutch and let you know what he has to say.

OMO

Measure the free length of the spring if you can, while you have the clutch off take it all apart and post detail pics I will point out any tips I can think of and point them out on your pics.

Thanks OMO. I look forward to see what he has to say.

Hoser, I'll plan to head out to the shop tonight and measure the spring and take some more pics. I'll try to post them up later tonight.

Thanks,

Rhinoguy

OK. I snapped some more pictures. Before I download and edit them to size, I'll post the spring measurements and some other data...

Using dial calipers, I measured the following:

Spring Free Length = 3.546 inches
Spring Wire Dia. = 0.245 inches

Also, stamped on the backside of the clutch was the following info:

ALT-6513P
94-07-27

So, this clutch was manufactured almost 14 years ago. The guy I bought it from on eBay sold it as "new" and it's pretty darn close to that, but it does look like someone mounted it to an Engine and spun it just enough to get some light rub marks on the pucks and such. In terms of wear and tear, I'd say 0 wear. Belt sheave surface look brand new. So whatever was done to it was not much more than mounting and spinning enough to have the pucks rub against the ramps ever so slightly. So, I can see why the guy listed it as new. I'm not complaining, since these FL250 Power Bloc clutches are hard to come by these days. In any case, that's the info and in the next post I'll upload some other pictures.

Rhinoguy

More FL250 Power Bloc pics...

ALT-6513P is the same number on my PB for my Pilot...

viewtopic.php?f=2&t=108
This guy 100% sure its for a FL250? You might call HRD or ATV Racing and see if they were the same...

See under the cap the D shape washer and the end of the shaft that has a flat spot that creates the D shape?
You have to make sure when you assemble you have it 100% correct, the number one failure and complaint with the PB clutch is that fitting correctly.

Also see
viewtopic.php?f=2&t=292

viewtopic.php?f=2&t=464

viewtopic.php?f=2&t=2238

Hoser, The guy I bought it from raced modified Odyssey 250's so I assume he knew it would work for an FL250. The person I bought it from is terrible at answering questions. I asked him a couple simple questions and never heard back from him, so I just decided to ask some questions here and do my own homework.

I see what you mean about the D washer alignment. When this clutch was test fit by previous owner, I can see where they didn't have it perfectly aligned before they rammed it together with a impact wrench. I did a little bit of hand work with a needle file and such to clean up the edge of the D washer a little. Everything fits together just fine now. Your warning and what I saw happen to the previous owner of this clutch will make me very careful when I assemble mine.

I'm waiting for my 7/8-14 bottoming tap to arrive so I can clean out the rusted up threads in my old Salsbury clutch. Then I plan to use a Grade 8 bolt to try to remove the clutch from the crank. I think it will come off OK, because it appears the Engine was gone through recently and the crank doesn't look rusted at all. My hope is that the Salsbury clutch was removed somewhat recently (during Engine rebuild), so hopefully it'll come off easier now.

Thanks for the info Hoser. Good reading there. I plan to bend a holding tool like shown to keep the spring compressed during assembly. Good idea.

I read about 12 weights, 13 weights, and then in another place I read about you were using 3, 4, 5 weights. What did you end up with? I know that my setup is different but I'm just trying to get an idea where to start. Right now, I only have 4 weights per puck. I don't want my Engine screaming all the time while cruising, but I do want more revs for a better holeshot and acceleration.

Who sells these weights? I asked the guy I bought the clutch from about extra weights, but never heard back from him.

Rhinoguy

I would start with 12 weights in each puck and work down from their. the 3-1/2 " spring is the shorter of the 3 standard people seem to ship with the clutches.

I have a real old PB that came off a 250 I will see if I can compare to one off my Pilot to see if the back set is correct, I wonder if the guy bought one of the PB's ludedude was selling then when he installed discovered it was not for a FL250 and removed, that's why it was removed never used? viewtopic.php?f=2&t=464
Do the weight blocks only fit one way?

Do a search for power and bloc lots of good info.

The pucks are symmetrical. I measured the width of both ends and they are the same. They fit in either direction, and not like the pucks that have a slightly different shape on each end.

I think I might try to give HRD a call too and see what they say about this clutch.

Thanks for help,

Rhinoguy

If you call you want to ask how to measure it correctly to see what the offset is, years ago the FL250 racing rules limited the OD so most PB clutches were put into a lathe to reduce its outside diameter to comply with rules, this should not be a issue for you since I doubt you will be racing and trying to pass tech?

Called HRD Racing today. The guy I talked with was very helpful. First of all, I told him the part number off the back of the clutch and he said: Yes it would work on the FL250, but he thought that it was setup for the larger 1-3/16" belt. He told me how to meaure it to confirm belt size. I did and confirmed that it is made for the bigger belt. This particular PB clutch was not made for the narrower stock belt as some PB FL250 clutches are. He said that stock driven clutch can be shimmed 1/4" and run with the wider belt.

At this point, I'm not sure if I'll install this PB clutch or sell it and look for a used set of Comet 94C FL250 clutches. Still mentally chewing on my options.

Rhinoguy

please let me know if you want to sell - i might be interested

OMO
Curtis

You know, I am beginning to wonder if the clutch I have is really for the stock belt after all. That's what I was hoping for when I bought it. In fact, not just "hoping for", but planning for it as fact. I went back to the Evilbay auction page and the guy I bought it from clearly stated in the auction that is was "for stock belt systems". Now, I know that the seller could have lied, or be ignorant of the facts. However, the guy was selling other FL250 race stuff at the time and it appeared that he had some knowledge since he was involved in racing the FL250's. I'm starting to ramble a bit here.... just background info sharing more info...

When I called HRD Racing today and told the guy the ALT # on back, he immediately said "yeah, that 13 is the right clutch for the 250". "13" referred to the last 2 numbers in the part number that I gave him. He then said that he couldn't remember if that was for the wider belt. Might be. He said I'd have to check/measure to be sure. I asked how to do it. He said to compress the clutch on a drill press and then measure between the sheave edges along the OD. He also said I could just pull out the spring and then push the clutch faces together and measure it that way. Since that was an easier way to do it, then I just pulled out the spring and pushed the 2 sheaves together.

Then I took my calipers and measured the spacing between the sheaves (along the top OD edges) and measurd the following: 1.10 inches. Keep in mind, that was the distance between the 2 sheaves at their outermost edge (max OD) of the belt riding surfaces.

Immediately, when I saw that it measured over 1", I concluded that it must be for the wider 1-3/16" belt, since the stock belt is 31/32" (.969 inches) wide - slightly less than 1". Then, later tonight, my brain was chewing on this and then I began to think that the clutch could possibly be for the stock belt width after all. If the spacing between that top edges of the 2 sheaves at their max diameter was only 1.10 inches, then why couldn't it be for the stock belt width??? That would mean that at maximum shift out of the clutch, the top edge of the belt would be just slightly below the maximum OD of the clutches. Then I began thinking that maybe this was in fact setup for the stock belt width like the seller stated in the auction. The guy at HRD Racing didn't know off hand for sure based on part number, so that's why he said to measure it. He didn't tell me (and I didn't ask) what the measurement should be if it was for the wider belt. I just ASSumed that since it measured a little over 1", then it must be for the wider belt since the stock belt is a hair under 1" in width. Later I got to thinking that it would make sense to design the sheaves with a hair more room so the outside of the belt doesn't ride up past the OD of the clutch sheaves.

I'm just bouncing this off you guys to see if my reasoning is right. I'm trying to play detective with an old PB clutch that has some uncertain history to it.

Anyone have a PB clutch sitting around that was made for a wider belt that they could pull out the spring, push the sheaves together, and measure the spacing between the sheaves at max OD?

Thanks,

Rhinoguy

After posting my long message, I realized that all the words could confuse what I'm tryin to communicate. Since a picture is worth a 1000 words, then I made a simple sketch showing the measurement that I took on the PB clutch I have here. Question is: Does this look like a PB clutch for the 31/32" stock FL250 belt size? I now think so, but just trying to get some more opinions.

I will dig out the PB I have off a FL250 and measure it tonight like in your drawing.

hey hoser if you pb is any good do you want to sell it?

OMO

Thanks for doing that Hoser.

Here is the clutch I have, its an old one has the replaceable plastic bushing not bronze.

Pucks are white

Pre D washer

Bolt and outer cover

Clutch bolt length