squid_on_a_300 Posted August 20, 2013 Report Share Posted August 20, 2013 I was looking at getting an 06 clutch spring for my 03 300 Pro to try and lighten the clutch pull a bit. My plans were to rebuild the master, the slave and change the spring. The shop I deal with is recommending I upgrade the clutch cover/slave to the 05 cover and convert to mineral oil...In anyone's experience does the upgrade make that much of a difference in clutch pull and clutch action? Or should I stick to my original plan? Any advice would be appreciated Quote Link to comment Share on other sites More sharing options...
lineaway Posted August 21, 2013 Report Share Posted August 21, 2013 If your clutch is hard, I would be looking at the correct finger height to make it lighter pull. Changing the spring is a good upgrade, but if the clutch pak is not in spec it will not change much. I think changing the cover just to go to the mineral oil is a waste of dollars unless you have issues with the original set up. Quote Link to comment Share on other sites More sharing options...
zippy Posted August 21, 2013 Report Share Posted August 21, 2013 My 03 had already been switched to mineral oil clutch before I got it. I think the original clutch cover was still used and just the internal rubber bits were changed. ( I have not seen the inside of this Clutch/engine yet so not exactly sure what all is in there) My clutch pull is fairly light, but to be honest I don't know if that is because of the mineral oil, the spring or adjustment................. Ya know I am really not helping at all here............. Quote Link to comment Share on other sites More sharing options...
richt Posted August 21, 2013 Report Share Posted August 21, 2013 Fluid type wont make any difference to lightness, they changed to mineral when some bikes leaked brake fluid into the trans oil. I was told by Gasser that if you change the spring to 06 you also need to change the retaining ring to 06 as a matched pair because it would have the effect of changing the measurement of the clutch fingers. consequently it wouldn't be as light as an OEM 06 clutch. Quote Link to comment Share on other sites More sharing options...
laser1 Posted August 21, 2013 Report Share Posted August 21, 2013 Fluid type wont make any difference to lightness, they changed to mineral when some bikes leaked brake fluid into the trans oil. I was told by Gasser that if you change the spring to 06 you also need to change the retaining ring to 06 as a matched pair because it would have the effect of changing the measurement of the clutch fingers. consequently it wouldn't be as light as an OEM 06 clutch. I dont think thats true Rich. I know ive changed a few older bikes to the 06 spring and never replaced plate - worked great. No change in finger height as I recall. Quote Link to comment Share on other sites More sharing options...
richt Posted August 21, 2013 Report Share Posted August 21, 2013 I dont think thats true Rich. I know ive changed a few older bikes to the 06 spring and never replaced plate - worked great. No change in finger height as I recall. The way it was described to me was that spring is slightly thinner and the plate is machined to accommodate it. I would like to make the clutch lighter on my 04 by just changing the spring and ignore what they told me. Their theory sounded plausible but I doubt it would cause a great problem. Quote Link to comment Share on other sites More sharing options...
laser1 Posted August 22, 2013 Report Share Posted August 22, 2013 The way it was described to me was that spring is slightly thinner and the plate is machined to accommodate it. I would like to make the clutch lighter on my 04 by just changing the spring and ignore what they told me. Their theory sounded plausible but I doubt it would cause a great problem. Well that would do it if thats the case - I could have missed that as it only takes a few thousandths of an inch to change the spring K an appreciable amount. I say try it - I have never changed plates and finger heights were always OK. Will make a noticeable difference in pull and make the engagement more progressive. The part numbers for the plates are all the same - so if its IS different, its backward compatible in theory. Quote Link to comment Share on other sites More sharing options...
sting32 Posted August 22, 2013 Report Share Posted August 22, 2013 (edited) My Opinion, and what I believe to be true... The pre 04 covers had a slightly thinner/smaller diameter on the plunger, which means for the exact same mount of cc's of fluid pushed from the master cylinder, it would move farther. back in the day, Raga (for a while) was reportedly using his 02 cover on even his 04 bikes, because the clutch acted quicker I think it was... Anyhow, smaller slave cylinder, which is reducing the "leverage" affect or what is it called hydraulic advantage? you are filling a smaller slave cylinder, less leverage. you know what I mean, it is like on a jack that takes 5 pumps to move 2cm, is easier to pump than one that moves 2cms in 2 pumps, which is an exaggeration, but is what is happening, on the same exact weight you are trying to lift. Mineral oil was about the rubber o-rings inside that slave piston/area. I myself prefer using dot5 {silicone} myself, I convert all my bikes back to this for 2 reasons, easier to find the dot5 than others, and silicone based might seem slippery'er to the master and slave cylinders (easier to move). I put 06 (and up) springs in 02's 03's and 04's FWIW. You MUST make sure the fingers are within spec, aka when clutch-pack is in spec the fingers cannot stick up past what is that spec 19mm? if the fingers stick up past that, you need to replace the metal clutch plates with ones that are thinner. thick clutch packs cause fingers to be too high. Don't push the envelope high fingers, as this will mean clutch will slip when you let clutch lever out (fully released). if the fingers are low, the clutch gets harder to operate, when at high end, it is easier to operate. Hope that helps, and if I am wrong about raga, it has been a long time since then, memory fades... Edited August 22, 2013 by sting32 Quote Link to comment Share on other sites More sharing options...
laser1 Posted August 22, 2013 Report Share Posted August 22, 2013 The original Mg clutch cases were somewhat weak and flexible - the "fix" was to goto Al and add ribs to stiffen it. (Not to mention the changes to the slave) When you actuate the clutch, you can watch the side case bulge. Regardless, They still work, but I think the stiffer design is more precise in feel. (not that it matters to me) Raga used to have AL side cases on his bike at one point - I forget when. Like you say - memory fades with exact details. The fingers are part of a asymmetrical teeter-totter. the short side acts on the spring - the tall side is acted on by the slave/top hat. Because of this, when you raise the clutch pak thickness, you lower the finger height and visa-versa. Thats also why when a pak would swell - it would get harder to pull the lever. Quote Link to comment Share on other sites More sharing options...
squid_on_a_300 Posted August 22, 2013 Author Report Share Posted August 22, 2013 Harder pull because there is less leverage on the fingers to move the spring, correct? So I guess I should pull it apart first and check the spec on the clutch pack before I do anything as the issue could just be with the thickness of the pac.. Quote Link to comment Share on other sites More sharing options...
laser1 Posted August 22, 2013 Report Share Posted August 22, 2013 Harder pull because there is less leverage on the fingers to move the spring, correct? So I guess I should pull it apart first and check the spec on the clutch pack before I do anything as the issue could just be with the thickness of the pac.. Yes - the finger height check is definitely the 1st step. Watch the jim snell video on clutch service and make sure you always lay the bike on its side when re-assembling. Quote Link to comment Share on other sites More sharing options...
lineaway Posted August 23, 2013 Report Share Posted August 23, 2013 Thanks Lazer, I liked all your input! I checked our old Raga compared to my `new` vintage Fantic. The old cable clutch was lighter! Might have to do the mod also. Quote Link to comment Share on other sites More sharing options...
squid_on_a_300 Posted August 27, 2013 Author Report Share Posted August 27, 2013 Found my problem...pulled the clutch out and the finger height is 12.75 mm and clutch pack is 10.2...now putting in 2 - 1.3mm metal plates will get me to back to spec at 9.8 on the clutch pack I'm assuming that will put the finger height somewhere back in spec...correct?...I was considering getting the 2 -1.3 mm plates and one 1.4 mm just in case... Quote Link to comment Share on other sites More sharing options...
jse Posted August 27, 2013 Report Share Posted August 27, 2013 Found my problem...pulled the clutch out and the finger height is 12.75 mm and clutch pack is 10.2...now putting in 2 - 1.3mm metal plates will get me to back to spec at 9.8 on the clutch pack I'm assuming that will put the finger height somewhere back in spec...correct?...I was considering getting the 2 -1.3 mm plates and one 1.4 mm just in case... I don't remember seeing what your plates measured out as to start with. If it's an earlier clutch pack, you could have a number of thickness' plates. If it's been replaced with a newer pack, both plates will measure 2.0, and you will then end up with an 8.8mm pack, which will not work. What is the thickness of the installed plates in your old clutch? Jon Quote Link to comment Share on other sites More sharing options...
squid_on_a_300 Posted August 27, 2013 Author Report Share Posted August 27, 2013 Sorry Jon..they are stock 1.5mm plates.....moot point though ..according to Rising Sun Imports the thinner plates are no longer made..so I had to order a new pack..should be here in a few days. With my enduro bikes I was told to soak the new fiber plates in gear oil for a few hours before I install...same here? Quote Link to comment Share on other sites More sharing options...
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