RCU Forums - View Single Post - ys engine surging at full throttle
View Single Post
Old 11-09-2008, 01:33 PM
  #11  
Tony Babington
Member
 
Join Date: Jan 2006
Location: Staffs, UNITED KINGDOM
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Default RE: ys engine surging at full throttle

This engine is quite frankly driving me up the wall. I have lapped in the rocker cover seal face and the carb seal faces, changed the ‘o’ ring seal on the air box and cylinder liner. Today I ran the engine at full throttle on the ground for a full tank without any problem. Left the engine for half an hour, re-fuelled, warmed up took off and after a couple of minutes at full throttle the engine lost power. I immediately chopped the throttle and the engine stayed at idle but would not throttle up again for quite a time, ( I presume while pressure built up again). The only seal I have not replaced is the front bearing oil seal but I can’t believe that it’s the problem. It has been suggested that the problem is with the piston ring or liner but the compression is so good I can’t believe that this is the cause. Still persevering !!