[KZScott]

EDIT. GO TO PAGE 4 FOR AN EASIER VERSION!

thought this might be helpful for new guys getting into drag racing with the first gen 12R
the purpose of the following mod is to get oil from the trans shaft to the clutch pack. Muzzy has a kit that modifies a sleeve and the hub (hard to copy without maching equipment) or you can drill the hub and do the flat spot trick or drill the pusher(with EDM).
I had a Muzzy modified sleeve and hub in my bike when i got it. I copied the drill pattern in the hub where the clutch pack goes for dads hub, and did a flat spot to the pusher. its very hard to copy the machining by the sleeve/hub nut on the hub. hes running an MTC lock up so his pusher is different than the stock ones, so ill include a pic of how to modify a stock one too

dont grind too much off or you will have too much oil in the clutch robbing power, and it will lower the oil pressure. start with a small amount and work up untill you no longer have dry clutchs.

 

[Hibs]

I haven't ever taken a clutch apart, so don't flame me. But I am going to be attempting this sometime with my new 12r in the near future. I'm trying to understand the first and second pic. The way the holes are in the hub now, do they go 3 holes/ 2 holes/ 3 holes / 2 holes all the way around? The ones with 3 holes you drill as marked, and the ones with 2 holes drill as marked? Just curious as to how many "sets" of holes their were, and if it mattered on what side of the hub they were on.

Also, when grinding the stock pusher, does it matter what side you grind down? I assume it doesn't.

 

[KZScott]

yes they go 2 holes, 3 holes, 2 holes, 3 holes all the way around, just count the notches inbetween to get the spacing, mark them with a sharpie before you go at it.
everything spins, so no it doesnt matter. :thumbup:

 

[KZScott]

bump

 

[Michaels12]

Thanks for putting this back up Scott....I lost the majority of my archived photos when my hard drive died....

 

[wylde]

Hey Scott,, in the pics above you have the holes in the hub... how many sets? i know they alternate but how many sets of 2 and how many sets of three? also why are the hole diameter different? ie. .071/.053 and lastly i know you say 1/8 to a 1/4 but how far up the shaft of the puller do you go? the diagram photo shows it almost the whole lenght but the actual photo shows a tiny bit shaved off?
so that is three questions i have. thanx

 

[KZScott]

leave 4 "grooves" between the grooves with holes

those are the sizes Muzzys picked to drill in the hub. ive since used larger and found no problems. the biggest thing is getting the oil supply to the hub correct by grinding the pusher

the diagram pic is with a stock pusher. the one with the circle and actual grind mark is an MTC piece used with a lock up. the oem piece is the same diameter all the way where the MTC piece is only the size of the oem piece at the tip, and is smaller for the rest of the way. this helps the piece to not bind in the trans if theres any side to side play. so you only need to grind the tip of the mtc piece to allow oil flow, but you need to grind the oem piece from the tip to where the piece enters the trans shaft. on a street bike it may be a good idea to only grind it far enough so that it remains "sealed" when the clutch pack is compressed, and when you pull the lever and pull the shaft out of the trans a little, have it "open" the oil flow by showing the flat spot. that way you only get oil when you pull the lever you dont really need any oil in there when its locked in and you are cruising

 

[Hibs]

BUMP... I'll be attempting to drill the hub and notch the pusher here in a day or two. My only question, my hub currently has no holes in it. Do you think it matters exactly where the holes are drilled, as in, the distance from the top of the hub to the bottom of the hub? Like you have in this photo, the 3 holes seem to be all about equal distance apart, from top to bottom. Is there an exact distance for the spacing or as long as they are about equal I should be OK?

Also, I assume this picture is just showing the muzzy modified sleeve? Anything I can do with the stocker, or just do the drilled hub and notched pusher?

 

[Hibs]

?? Any help from someone who has done the drill mod?

Also, just making sure, those bit sizes seem TINY (I don't even have any that small in my drill bit kit)... looks like I'll have to run to the hardware store and buy a few bits.

 

[KZScott]

it doesnt have to be exactly like that as long as you space them uniformly. imo after looking at this now, and having seen a lot more hubs (brands with and without mods) since i wrote this, im guessing Muzzys did this to make it hard to copy(so you buy their stuff). IMO if you just drill some 1/16- 1/8 holes you will be fine. as long as it allows the oil to be dispersed evenly to the pack. ill be doing a new one in a few weeks, ill get new pics then, just be sure not to hit where the steels slide, do the very middle of the grooves and try to chamfer the edges with a larger bit top and bottom
dont bother with the sleeve, i didnt on dads 00, just notch the pusher a bit.
one more thing, if you dont notch the pusher all the way, you will only get extra oil when the clutch lever is pulled in. no need to oil the pack when its locked in.

 

[Hibs]

it doesnt have to be exactly like that as long as you space them uniformly. imo after looking at this now, and having seen a lot more hubs (brands with and without mods) since i wrote this, im guessing Muzzys did this to make it hard to copy(so you buy their stuff). IMO if you just drill some 1/16- 1/8 holes you will be fine. as long as it allows the oil to be dispersed evenly to the pack. ill be doing a new one in a few weeks, ill get new pics then, just be sure not to hit where the steels slide, do the very middle of the grooves and try to chamfer the edges with a larger bit top and bottom
dont bother with the sleeve, i didnt on dads 00, just notch the pusher a bit.
one more thing, if you dont notch the pusher all the way, you will only get extra oil when the clutch lever is pulled in. no need to oil the pack when its locked in.

Thanks. I was having a hell of a time finding those drill bit sizes. Bought a micro-drill bit set at Harbor Freight tonight, metric ranging from .5mm to 3.0mm.... what's the reason to chamfer the top and bottom ones? why not all of them?

From the kit I bought, I think I'll use the 2.0mm (.078") to drill all the holes, then use the 2.35mm (.092") to chamfer it.

And with the pusher, how far is not all the way? Should I follow the pattern you have colored in you pic?

I'll be doing mine tomorrow or friday, I'll take some pics along the way

 

[KZScott]

top and bottom of each hole(both sides of all the holes)
yes to the coloured pattern, you should see a wear pattern on your piece unless its new, that will tell you where to stop

 

[KZScott]

so i did a practice run with larger holes on a used 02 hub. i used the same spacing as my original muzzy modified 01 hub. this hub is at the point where ill start my season with it, but probly replace it soon.....
holes are 5/32, not really room on the "top" of the hole for a chamfer, but being so big i dont think they really need it. (my .02)
3 marks stands for 3 holes, 1 mark stands for 2 holes....

 

[Hibs]

you have stated 4 "groove" spacing in between, but it doesn't work out perfectly that way (as seen in your above pic, you had to use a couple 3 groove spacing).

on mine, i did 3 groove spacing the whole way around, and went ahead and drilled 3 holes for each one (versus doing the 3 then 2 then 3 etc). i used my 2mm drill bit (.078") and did a chamfer on the top and bottom hole in each groove with a 3mm bit. I also notched my pusher just like your picture, i used a tad over 1/8" flat spot.

not sure if the way i did it will give TO MUCH oil to the clutch pack? i rode the bike a good 80 miles today, felt great. I'm going on a 1000 mile road trip leaving tomorrow, be back Sunday. I plan to pull the clutch pack out once I get back and inspect it.

 

[KZScott]

srry, the muzzy is definately spaced like the last pic. but you would have found out if you marked out everything before drilling any holes.

 

[Hibs]

srry, the muzzy is definately spaced like the last pic. but you would have found out if you marked out everything before drilling any holes.

lol ya, i did. i marked everything, then was like WTF? as it didn't work out right. So i just did 3 groove spacing and it worked out fine.

 

[Hibs]

Here's my pusher...

I'm right at an 1/8" where I grinded it down. I pulled my clutch pack last night, the first couple fibers had oil on them, and there was some oil in the bottom of the hub, but the majority of the fibers were dry. I think I'm going to grind the pusher more towards 1/4" and see if that helps.

 

[KZScott]

nice pic. report back!

 

[shiphteey]

Hibs, you're too slow to need any mods. Learn how to fucking ride the bike and put up some respectable numbers, BIATCH.

 

[KZScott]

lets keep this post for information plz. anyone can burn up a clutch no matter how fast they are or arent. this is to help that issue....