hi i got a 2005 piaggio nrg power dd with polini cast iron 70cc and 70mj in dellorto 17.5 carb and standard air box and i was riding it and it started to lose power a little then and making a squeel as i slowed down it cutout and walked it home then tried to start it and after 15mins kickin starting it finaly fired up but cutout on any thing less than full throttle and it sounded normal as soon as i rode it to the end of the road it started rattling and knocking and cutout again and that all it keeps doing.(the standard crank has about 15,000 miles on it roughly coz speedo didnt work for few months) HOPE SUM1 CAN HELP THANKS (70 kit got about 1200 miles on it and it twin rings) and seems to have compression when put finger at end of exhaust

simon, May 2010

ohh dear she has nipped up hasnt she,send it my way i love doing these motors. am i a bit sad?expect the piston to look like someone has put it on a cheese grater and the barrel will look similar.ps cast iron barrels are not good news they suffer from bad heat transfer and often seize up always go for an aluminium barrel thats nickel plated (but always make sure your oil feed is good)and if its not then stick some 2 stroke oil in the petrol tank.

adam bike doctor, May 2010

No Oil in tank = rebuild. Basically the two stroke engine works by lubricating as it goes. I would put money on rings piston rebore and more than likel you will have to split your engine and replace the bearings inside.
Cost if you take it to the shop it will cost quite a few hundred. :-(

bb, May 2010

seizure, rebuild imminent, good job should cost 250-280

m, May 2010

thanks bb i forgot to mention it got oil leak the hose that goes from oil pump to carb has been seeping from the joins which i and the garaged tried to stop but just couldnt so i was pre mixing but forgot the oil the last 2 times i filled petrol tank and forgot to add it after i got home too( do u reckon it going to need a rebuild and wot sort of cost am i looking at)

simon, May 2010

Nice load of information there to get some advice.

You need to test for compression by taking the plug out and pop finger over hole when trying to start. Give away is how hard is it to kick over. Is there much pressure on the kick start, does it gind away?. You can get it tested.
However a bearing may have popped in the engine at the bottom of the crank. The extra pressure from the bigger top end has made it strain!
By what you are saying its defo had a seizure you just need to find out where!

bb, May 2010