Keiran95 Posted March 25, 2012 Posted March 25, 2012 okay so i have finally got down to having a rebuild but i have made the mistake of not looking up how the powervalve is set up correctly, i'm not sure if i will be able to get it to work again, is it hard? could anyone help me?
Moderator Airhead Posted April 1, 2012 Moderator Posted April 1, 2012 havent you got a manual keiran? what exactly are you wanting to know?
Keiran95 Posted April 9, 2012 Author Posted April 9, 2012 sorry for the late reply, i have been really busy.. i have noticed some scuffs on my old piston and it seems that the power valve has scored the piston. has anyone else had this problem?? Also the piston was in a serious state (looked like a crumpet on the top) i beleive this is because it was running to hot and i had a leak from the head and barrel?? but i'm just wondering if the scuffs on my powervalve is OK and it will run again? but i dont want to ruin my new piston.. any ideas?? thanks for the time and effort please get back to me as i want to do a proper job as the bike is my pride and joy
Keiran95 Posted April 10, 2012 Author Posted April 10, 2012 how long should i run the new piston in for???
Moderator Airhead Posted April 10, 2012 Moderator Posted April 10, 2012 wont need much keiran, about 300 miles i'd say. The concern is what happened with the first one? I've heard lots of times how DTR engines have had pv piston collisions! is this what yours had? some pics would have been nice, and of the piston (crumpet) crown too...doesnt sound good
Keiran95 Posted April 10, 2012 Author Posted April 10, 2012 i believe that the piston was running too hot due the head and the barrel leaking, thats what the guy said that rebuilt my engine for me anyway. as you know airhead i only know so much i think i have left the piston in the garage so i'll get a few pics tomorrow, its a right state.. and it seems that as the pwervalve has opened or shut it has tilted the piston slightly and left a small score all the way down it, and the top of the piston that should be smooth is like a crumpet - i was lucky and got it sorted before it smashed into a million pieces
Ryan09 Posted April 15, 2012 Posted April 15, 2012 If it looks anything like this then it was due to seizing.. In my case running out of fuel doing 75mph on the m25 and not changing to reserve quick enough leading to a nice rear wheel lock up! This piston was changed after 14000 miles by the way. It has the scoring all round the piston, When you say 'crumpet' it may just be a build up of carbon which would be normal. Doing a top end rebuild is really simple, its only a 2 stroke after all.
Keiran95 Posted April 16, 2012 Author Posted April 16, 2012 Nothing atall like yours, my parents have binned the piston now before i could get some pictures, it looked like it had been bubbling on the top of the piston, but it was still running when i went to rebuild it... just with massive lack of power
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