The clutch/brake is binding whilst cold and stops the chain after running for a few minutes as it gets very hot. The release mechanism works but the clutch/brake is not fully released unless pressure is applied to the clutch/brake handle

There is a number of ways to re load the brake, you can either remove the clutch and sprocket, the brake will then go back onto the saw enabling you to use the hand guard on the saw to load the brake ( to remove the clutch, there are two cut a ways in the clutch centre designed to enter a flat screw driver into, then strike with a suitable hammer to remove, it is a left hand thread ) or you can remove the hand guard from the saw and use this as a tool to re load the brake, or you can clamp the cover in a vice ( be carefull not to damage the cover ) then use a strudy pair of pliers or grips in the three legged loading mechanism and turn it to load the brake.

Hi
I have seen something similar on my own saw some time ago. Probably two things have gone wrong. First there is something wrong with the transfer mechanism between the clutch handle and the brake spring. I do not remeber the exact detailsy, but there is a plastic part engaging a metal part in the transfer mechanism between handle and spring, that tends to wear out so that it will not release the spring when moving the brake handle. (look at the engaging mechanism where the handle is turning on its axle/bolt) If you take off the chain guard / cover you should be able to follow or see this mechanism and use a screwdriver and a pair og pliers and try to move the transfer mechanism so that the brake can be set to the released position. Once this is done the brake mechanism/cover can be taken off and you can clearly see what part that needs to be changed (I think it was the handle itself, due to worn out enganging plastic lugs). The brake spring obviously needs to be disengaged when assembling and disassembling.

Whent it comes to chain lubing, you can try to clean out the oil tank, blow through the hoses and look for dirt and particles clogging the lube circuit. As a test, when the lubing is working correctly, the chain should throw off visible amounts of small drops of oil from the tip of the blade, when you let the chain run at working speed just in front of a piece of paper or cardboard. If no oil stains appear, the lubrication is failing and overheating and excessive wear will occur. Use the correct oil too. The wrong type of oil can potentially ruin the lube circuit. There is a small plunger-type oil pump that is driven by an excenter located near the inside of the chain sprocket drive shaft. You can easily test its function by pressing the plunger carefully and see whether oil comes out on the lube oil opening. It should be cheap to replace if broken.

I hope this can help you.

You need to release the brake mechanism in the cover so that the brake band will expand enough to pass over the clutch drum. You should have released the chain brake before removing the cover, but that doesn't help now. Use a wide heavy screwdriver to release the mechanism. Hope this helps!

You should have released the chain brake before removing the side cover. Try using a wide, heavy, flat-blade screwdriver to release the toggle mechanism for the brake in the outer cover which should expand the brake ring to allow it to go over the clutch drum. Hope this helps!

It's probably the chain brake not disengaging. If you are handy you can remove the clutch guard and spray some WD-40 around the chain brake (avoiding the clutch with the lubricant) and move the chain brake mechanism back and forth a couple times and see if it releases. If not, take it to a qualified mechanic.

hill hold,it stops the car rolling backwards when youre on a hill with the clutch in and releases when you let out the clutch taking off,it can be adjusted if its not working correctly,very handy feature to have

Broken clutch spring.

Hi! Brake issue should clear with use however as it is a floating caliper you may want to strip it and cleaning out any **** from behind the pads, alternativly and being carefull use a quality rubber mallet and tap the outside of the caliper a few times apply the brake and do it again until the resistance is lost when pushing the bike forward and applying then releasing the front brake.
Sounds like clutch problem regarding No gears, if it has a duplex or even triplex chain these can break. If direct drive then clutch centre may have detatched leaving plates in limbo. if the plates were stuck together you would get gears. Without engine running push into any gear rock bike forward and backward if engine turns then keep clutch lever in and keep rocking this may free em off if not take cluctch cover off and release them.
Hope this helPS! Good luck!
Paul 'W'
Onyer~EDson(:0)~[><

I used applman08's solution. A few pointers:
0. This problem occurs when you take off the side cover while the brake is set. So after you fix this, don't do that again.
1. When removing the clutch, place the screwdriver in the notch next to where it says "off" and tilt the screwdriver down so that when you strike it you are applying a clockwise shock force that is almost horizontal (assuming your 455 is on its side).
2. DO NOT remove the spring! There is a plastic housing that basically holds the brake mechanism in place (secured by 4 screws). If you take that apart, and then take out the spring, you will be learning how the brake works and spending some time compressing that spring and getting it back in. You'll have to come up with something clever to get the spring in depending on tools available.
3. Going back to 1. - get that clutch off, put the side cover back on, getting that brake lever lined up with the very-difficult-to-grab three-toothed mechanism for engaging the spring. Tighten down the side cover, or hold it snug with one hand while you lever the brake handle with the other. You will hear a satisfying snap as the braking mechanism (with the spring I told you not to mess with) resets.
Note: You can probably reset the braking mechanism by manually turning that three toothed gizmo but it's really hard to grab and the brake handle fits it perfectly. The key is you've got to turn that about 60 degrees.
Good luck, this was an annoying problem.

umh,have you checked the cambelt/chain tension its a bit strange for two sensors to go down at the same time !! cranksensor would make it stop but normally on sequential injection if the camsensor fails the car will keep running untilll you stop it then refuse to start....