Hi Folks

just got a new 09 280 and I'd like to fit a larger clutch master cylinder and hose which I already have but which is designed for brake fluid not mineral oil.

I had thought I would need to change the seals in the clutch case to suit brake fluid but my dealer tells me that they are now coated and will work with either mineral oil or brake fluid. Before I trash the seals in my new bike can anyone confirm this ?

MANY THANKS

Glenn, good luck with the Gasser mate, the 09's look the dogs B*****ks one day I will have one again, oh yes are you going to start a Gasser Virgin thread Copey aint going to happy

Edited November 15, 200817 yr by The Addict

Cheers Justin

I'll let you know how it goes

Hi Glenn,

I was wondering why you wanted the larger clutch master cylinder?

The clutch slave and bleed nipple will also need to be cleaned out. The O ring seals have been teflon coated FKM, from memory, for many years now and as such would be fine for either mineral or synthetic "hydraulic" fluid. Around 2005, the seals were a mixture of O ring and cup seals, it was the cup seals that were specific to oil type, being supplied in green, for mineral oil and black for DOT 4.

Bye, PeterB.

Glenn, good luck with the Gasser mate, the 09's look the dogs B*****ks one day I will have one again, oh yes are you going to start a Gasser Virgin thread Copey aint going to happy

I am having a good chuckle soo far! Nutter!

Hi Glenn,

I was wondering why you wanted the larger clutch master cylinder?

The clutch slave and bleed nipple will also need to be cleaned out. The O ring seals have been teflon coated FKM, from memory, for many years now and as such would be fine for either mineral or synthetic "hydraulic" fluid. Around 2005, the seals were a mixture of O ring and cup seals, it was the cup seals that were specific to oil type, being supplied in green, for mineral oil and black for DOT 4.

Bye, PeterB.

Thanks for the that Peter

I'm finding that I dont have as much feedback in the clutch system as I did on my sherco so its harder to predict where the bite point is. Most of the GGUK team run the large master cylinder and as I have one lying around I thought I may as well try it.

If my new bike has any issues I think that nice Copemech chap will be considerate and not say why didnt you buy another sherco you baldy fool ! Evening Cope ........

Edited November 15, 200817 yr by Baldilocks

If my new bike has any issues I think that nice Copemech chap will be considerate and not say why didnt you buy another sherco you baldy fool ! Evening Cope ........

Bet he dont

Hi Folks

just got a new 09 280 and I'd like to fit a larger clutch master cylinder and hose which I already have but which is designed for brake fluid not mineral oil.

I had thought I would need to change the seals in the clutch case to suit brake fluid but my dealer tells me that they are now coated and will work with either mineral oil or brake fluid. Before I trash the seals in my new bike can anyone confirm this ?

MANY THANKS

Since you have the system apart, why not change to Silicone (DOT-5) which should give a little smoother action. It works a little better in colder weather also. Silicone fluids exhibit significantly lower changes in viscosity when compared to petroleum-based fluids (due to it's viscosity-to-temperature coefficient). The Silicone is compatable with all the seal/o-ring materials.

Jon

Thanks for the that Peter

I'm finding that I dont have as much feedback in the clutch system as I did on my sherco so its harder to predict where the bite point is. Most of the GGUK team run the large master cylinder and as I have one lying around I thought I may as well try it.

If my new bike has any issues I think that nice Copemech chap will be considerate and not say why didnt you buy another sherco you baldy fool ! Evening Cope ........

Hey matey, gone for the top performer have you? They are just ****e-hot! And I am NOT! Probably why I cannot get on with them.

Opinions may vary, but I think you need to leave it alone for a bit and adjust. Not that I like the way that, or the shifter, or the kicker work on them anyway. It is a PRO, I am NOT!

Running the clutch hydroulics through my simple mind tells me that a smaller MC bore would push less fluid per stroke and therefore increase sensitivity to the feel. Maybe I am wrong? The pack thickness is said to vary the progression as much as anything. I do not know, as every one I have ever ridden felt different to me. Ask Peter B what he thinks!

I hope you get on well and do not fall over and flood the thing!

MC

Cheers Copemech

I know what your saying but I think the larger volume cylinder has a smaller diamater bore hole or the leverage ratio is slightly different. The bigger cylinder when fitted to a scorpa or a mont makes the clutch action lighter so i'm thinking that it must push less fluid per stroke of lever ? I mention the leverage ratio as if you look closely at the connection between piston and lever it doesnt line up perfectly so there is scope to adjust. I think that s why my sherco clutch action was slower / softer with the midi sherco standard AJP lever compared to the long lever.

Hi Folks

just got a new 09 280 and I'd like to fit a larger clutch master cylinder and hose which I already have but which is designed for brake fluid not mineral oil.

I had thought I would need to change the seals in the clutch case to suit brake fluid but my dealer tells me that they are now coated and will work with either mineral oil or brake fluid. Before I trash the seals in my new bike can anyone confirm this ?

MANY THANKS

Sometimes you can change the leverage ratio by running a different type of lever. I run a modified Suzuki brake lever on my Pro, which gives me a little better ratio (the adjustment screw is farther out from the pivot point which moves the M/C plunger farther for each degree of lever movement) and I like the straight blade design as it gives a better "feel" than the curved standard design.

Jon

Dale had a '09 Gasser at the Octobertest, and as I always say hello and chat a bit, one thing that impressed me was the lightness of the clutch pull on the new on sitting there(working the finger while talking), as once again, these things seem to me to vary with each one I ride, I dunno the answer totally, other than the thinner pack, taller finger thing. And if you do not know where yours is at, well? Good thing is that it is adjustable!

Hi Glen,

I have always found the post 02 PRO clutch action to be really bril, light action with lots of feel. A friend had a new GG that had an odd feeling clutch action, it turned out to be the small bore clutch hose that was trapped behind the electronic unit up in the headstock, creating a kink in the hose that was restricting the fluid. A new hose fixed that problem. You may have something similar.

I don't know what master cylinder's the guys up your way are using for changing from standard, the older style, large case AJP master has the same diameter piston as the PRO master.(9 or 9.5mm, can't remember) so any advantage can only be in mechanical leverage. The only other area that affects clutch "feel" is in the pack height, the higher the pack height the less mechanical advantage from the 10 clutch fingers and the harder it is to pull in the clutch lever. I haven't heard of any problems with the later clutch fibres so I doubt you have a pack height problem.

Bye, PeterB.

So there you have no answers, yet I can tell you it will still feel like a gasser clutch, and not what you are accustomed, not bad, just different! I think you are still in Gasser Shock! And will not recover(like me) untill you get back on a conventional bike! You are just too old and set(once again like me) although I will not knock you for trying! It is all good!

Glenn, hows the Gasser going mate? has it lunched the gearbox yet?