TOPIC:

The 'old' way to de-coke a two stroke exhaust was with caustic soda, though not sure if that's still available. I DO remember many years ago a couple of friends who were two stroke fans reckoned the best way to unblock an exhaust of a bike that had been running rich, was to find the steepest longest hill, and ride the bike down as fast as possible, throttle wide open and engine screaming. Apparently that did work. However, if you blow your motor up trying that, neither I or the Gilera Network can be held responsible !!

Most of the two-strokes I've worked on lately require the silencer to be repacked at regular intervals.

The GFR one seems sealed for life. Not even pop rivets to drill out and replace to get it apart as far as I can see.

There might be a build up of carbon in the expansion chamber and caustic soda (in some drain cleaner products) is supposed to work. Another option is to burn it out but I don't think I'd want to try this with a rare GFR exhaust. Particularly as re-packing could be a problem.



As to carbon on the piston crown and combustion chamber a "dealer's decoke" is the only option.

Hi Thanks for the replies , I know the piston side is good as I had it replated and new piston recently , as you say the silencer is sealed , I will try the caustic soda approach over the next few days , things are looking good the bike is almost back to how it should be after a long lay up , hopefully this will be the final fix to allow me to use it again.
thanks again for all the advice
Neil

Hi Again , sorry to pester you but I have a question to ask with regards to ohms readings from the magneto , I disconnected the 3 pin connecter going to the magneto 2 yellow and 1 white wire and measured ohms down the line to the magneto
white to earth 1.5 ohms
yellow to yellow 0.5 ohms
these readings seem low but ive no reference can you help.
thanks again

They sound low, but it's been ages since I had the ignition winding go on mine. I'll try and get to one of mine to do some resistance tests but I have to move a couple of bikes to get to a GFR so it won't be until next week (off to a hill climb this weekend).

thanks again some readings to compare would be great.
enjoy the hill climb and no rush with readings as im back offshore next week .