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I posted how to push fluid back up into a brake reservoir, but the clutch hydraulics are virtually identical with the clutch piston being synonymous to the pistons on the brakes, it's all just simple hydraulics with the biggest difference being it uses DOT fluid or it uses Mineral Oil. There are very few high spots in a clutch hydraulic system where air can be trapped, so bleeding a trials bike clutch is Not generally a significantly difficult task unless you encounter a mechanical problem such as deteriorated rubber bits at either end of the system. Add: parts diagrams show your clutch master to be an AJP model that uses DOT fluid and not Mineral Oil, for a shop to not want to service an AJP clutch they must be a little bit clueless or simply don't want your business, the same parts were commonly used on additional bike makes and models. The Slave cylinder and piston is unique for your bike but the 2 o-rings inside it are nothing special, the rubber o-rings simply need to be compatible with the hydraulic fluids you are using and you can source appropriate o-rings from anywhere that sells o-rings and or hydraulic service supplies.

Thanks a lot for your suggestions!

If your valve clearance has never been adjusted, that's your problem. The adjuster is the same size as a red Robertson socket screw head, you can improvise a tool using a short stick of wood and thread a square head screw into one end of the stick 🤓 have a micrometer handy to test the dimension and feel of the feeler gauges because valve clearance accuracy is critical.

Hello, i have a pair of aprilia TRX311 forks ans would likt to service them. anyone knows where to get parts for them? what oil do they need and how much? Kind regards Bob

The Inch Perfect rides include the new Escape XR if anyone is interested - quite a few of the slots for that bike gone. We will put a small area aside to test it. Still plenty of chance to try out the Factor-e. https://inchperfecttrials.co.uk/products/2024-em-escape-xr-enduro-tyres

Thanks a lot for your suggestions, i'll try to check minimum rpm's and clearance valves.

What is your idle RPM's set at? 1800? If not that would be the first thing I would set. If you haven't done it in a long time you might consider checking your valve clearance next as if its happening when getting warm it could just need that rare adjustment. I can't say this will fix the issue but if the tick-over or vales are not set correctly when they warm up I have seen my idle drop a bit causing me to drop below the 1800 causing just enough of an issue for stall issues and vales can cause cause misfires and stalls as well when warm. Good luck.

Maybe a previous owner modified it to suit a different axle. If the hole is 12mm, the original threaded hole may have been drilled out and bushed to suit a through axle.

Request to new members... Would you mind putting your query into the dedicated sub-forum for the bike in question?

Let"s back up a little bit. Did you have the clutch apart?

Thanks for the offer but Australia is a bit far to pick up. I’ll hoping someone will come up with a motor for me in England.

Hello everyone, I have a problem with a 2005 Cota 4RT. After 10/15 minutes of riding, the bike shuts down, it seems to be a lack of fuel supply. As soon as it happens, I remove the spark plug and find it dry. After this, the bike starts up again immediately but then shuts down again after a few kilometers. I have replaced the fuel pump and filter, but with no results. When the engine is about to shut down, if I pull the clutch, it does not shut down, so in neutral position the engine runs well without issues; as soon as I shift into gear and increase the revs, it starts to misfire until it shuts down. Has anyone ever had a similar problem? Thank you for the help!

Hi everyone, I'm a new member, writing from Italy. I own a Beta Rev and a Cota 4RT.

I've got a model 49 250 Sherpa T motor and a Campera 175 motor available. Both require overhaul. Location Gladstone, Queensland Australia

THANKS FOR RESPONDING, IT IS HARD TO BLEED W/MY HARBOR FT PUMP WHICH MAKES SENSE IF THE PLUNGER IS NOT ADJUSED RITE

THANKS FOR RESPONDING, ILL GIVE IT A SHOT CANNOT FIND ANYBODY IN B'HAM THAT WILL LOOK AT A 2001

Hello, Fortunately, I noticed my Mountain Cub (1965?) trials conversion bike stopped pumping oil before it got too hot. I assumed it had a bad oil pump. I found a new NOS pump for $50, so I went ahead and bought it and installed it (not a fun job). Unfortunately, my bike still isn't pumping oil. Although I'm not a triumph cub engine expert, I have rebuilt, from the crank up, three motors and they have ran great after my rebuild, so I do know my way around the motor. I was very careful to install the pump correctly and it was spotless when I installed it. Could the "dry" sump not have enough oil in it? If so, how would I add some oil? To note, I haven't pulled the copper lines that go to the rockers yet and checked for blockage. Note - the bike had been sitting for about six months prior to me noticing it wasn't pumping oil. Thanks for any input.

I had a bear run across a section of the loop trail I was on once. Small black bear so not sure how risky it was, still unnerving, but was interesting to get a glimpse of one on the ride for me and my riding buddy.

It could be also that you need to adjust the screw on the lever that presses on the master cylinder piston. If the piston is not in the correct position, when pressed or opened, it effectively blocks fluid flow and won’t drain and it won’t allow fluid to flow from the bottom up either. Screw it out a turn and try again. Turn the screw, little by little, until you can pump fluid.

Any Sherpa T or Alpina engine would fit straight in. Some had different exhaust pipe fittings onto the barrel but the engine mounts are the same.

Adjust, repair or unplug the master cylinder so it lets fluid up into the reservoir when the pads are pushed apart, no flow back means you have a problem.

HELP. USED VACUM METHOD HELD 25 INCHES COULD NOT DRAIN MASTER CYCLINDER TRIED PUMPING FROM THE BOTTOM UP..NO RESULT. ANY SUGGESTIONS

I think you narrowed it down yourself, the problem manifested after you used a pressure washer on it, so you now have water somewhere you should not have water and you need to dry it out. Fortunately water evaporates so dismantle the electrics and dry them out and they will likely function again. On a Montesa that would be the big plug with all the pins that connects to the black box, look for similar connection on your machine. ... and avoid using pressure washers they destroy motorcycles as fast as they clean them.

I have a 175 Bultaco Sherpa with a very poorly engine that apprears to have eaten its 'self in pieces. If I can find the parts I would like to rebuild the original engine at some point but does anyone have a 250 or 325 engine for sale that would fit straight in to get me riding again? Any help would be much appreciated!

Hi guys, how do I remover the black plastic inlet fitting from a grimeca rear master cylinder? I'm rebuild it and I think there may be a leak from it. Thanks