I just had my 94' KDX200 engine rebuilt by one of the local shops. I sent it to be rebuilt because one day while riding it went lean on the pilot and wouldn't idle. The flywheel cover was also filled with oil, so the crank seal must of been leaking.
Last time it was rebuilt was just afer I bought it 3 years ago, just the bottom end because the top end was still good.
The engine was a mess this time, the crank bearings were gone along with the transmission bearings. The crank pin out of spec and pitted, the con rod big end bearing was bad. The cylinder had a slight scuff on the exhaust side and the exhaust port where the main valve is was cracked. There was a lip at the top of the cylinder from the rings, there was so little compression I could start it just by thing about it.
Anyways I got the engine back a couple of days ago after putting down $1200 cdn. It has a new vertex piston, recoated cylinder from Mongoose Machine, new rod and bearings everywhere. I also modified the stock pipe.
The bike before had and still does have a steahly flywheel weight, wiseco piston, and a 1/2 inch reed spacer with 45p jet, stock needle in middle position, and 158 main (which is too rich).
I thought the bike would scream with the new cylinder, piston and the modded pipe. Total opposite, I can push the bike faster, it ran better before. For breakin I took it easy for the first couple of hours. It now has three hours on it. The bike still pings on deceleration (it did that on the last ride before rebuilding, I know it's lean), it has flat spots in the mid range where it comes up to a top end which is stupid. It won't rev out in any gear not even neutral, it feels like the wiseco piston before it was warmed up. I could top out at 70 mph before now it tops out at 52mph with lots of throttle movement left, but physically won't rev any futher.
I know my jetting is off, but for the bike not to rev out it seems the problem isn't jetting. Could the timing be off, not broken in yet, exhaust leak, the pipe itself, reeds (they're still good), to rich or lean main jet. I'm stumped and would appreciate any help.
Thanks, and sorry for the long post.
Tamean
Last time it was rebuilt was just afer I bought it 3 years ago, just the bottom end because the top end was still good.
The engine was a mess this time, the crank bearings were gone along with the transmission bearings. The crank pin out of spec and pitted, the con rod big end bearing was bad. The cylinder had a slight scuff on the exhaust side and the exhaust port where the main valve is was cracked. There was a lip at the top of the cylinder from the rings, there was so little compression I could start it just by thing about it.
Anyways I got the engine back a couple of days ago after putting down $1200 cdn. It has a new vertex piston, recoated cylinder from Mongoose Machine, new rod and bearings everywhere. I also modified the stock pipe.
The bike before had and still does have a steahly flywheel weight, wiseco piston, and a 1/2 inch reed spacer with 45p jet, stock needle in middle position, and 158 main (which is too rich).
I thought the bike would scream with the new cylinder, piston and the modded pipe. Total opposite, I can push the bike faster, it ran better before. For breakin I took it easy for the first couple of hours. It now has three hours on it. The bike still pings on deceleration (it did that on the last ride before rebuilding, I know it's lean), it has flat spots in the mid range where it comes up to a top end which is stupid. It won't rev out in any gear not even neutral, it feels like the wiseco piston before it was warmed up. I could top out at 70 mph before now it tops out at 52mph with lots of throttle movement left, but physically won't rev any futher.
I know my jetting is off, but for the bike not to rev out it seems the problem isn't jetting. Could the timing be off, not broken in yet, exhaust leak, the pipe itself, reeds (they're still good), to rich or lean main jet. I'm stumped and would appreciate any help.
Thanks, and sorry for the long post.
Tamean
