First off I'm new on gstwin and have already learned alot and like how generous you guys are with your knowledge, and now i would like to tap into that knowledge. Ive been riding for four years with no problems on my gs. My good friend recently got a gs that ran when he got it but ran funny. He proceed to tear down the top end of the motor and ended up replacing the piston rings, and finding no other problems. He put it back together and when ready to run it with fresh battery, new starter, and fuses all it would do is turn over real slow. anybody have a similar experience or have any suggestions?
thanks
first off; you've ridden a gs for 4 years and just now posted first post? welcome aboard! :cheers:
second; new rings with no assembly lube or oil can cause high friction and slow turn over (not to mention damage), you could try putting some oil in cylinders and turning it over by hand to lube the walls. also incorrectly installed cams can cause insanely high cylinder pressures and slow turn over with no combustion.
maybe some one with this same symptom has found a clear solution and will chime in
good luck!
Hi Marcosmyros and welcome to our crazy little world here at GStwin.com,
Your friend could have done a lot of things wrong in reassembling the engine.
The cam timing could be off -- this is critical and even a tooth off makes a big difference.
It could be incorrect assembly.
It could be piston ring breakage (it can happen when reassembling if you are not careful).
It could be many causes.
Did he check the valves for leakage or bending?
Why did he replace only the rings?
Did he measure the cylinders, pistons, piston pins, etc?
If this was a cheapo engine rebuild from the start because he thought he could get away with that, it sounds like that's what he might have gotten, which is a drag.
Did he replace any other parts at all?
If not, my guess is his approach of just putting in new rings and reassembling it is faulty and is the likely cause of the problems he now faces.
Time to do it correctly, I'd bet.
He can at least check the cam timing and make sure all the timing marks line up correctly, on the cams and head and the crank and engine cases.
I'd bet he made some mistakes in not replacing needed parts and on reassembly.
Good luck!
Quote from: Trwhouse on December 14, 2009, 06:49:44 AM
Hi Marcosmyros and welcome to our crazy little world here at GStwin.com,
Your friend could have done a lot of things wrong in reassembling the engine.
The cam timing could be off -- this is critical and even a tooth off makes a big difference.
It could be incorrect assembly.
It could be piston ring breakage (it can happen when reassembling if you are not careful).
It could be many causes.
Did he check the valves for leakage or bending?
Why did he replace only the rings?
Did he measure the cylinders, pistons, piston pins, etc?
If this was a cheapo engine rebuild from the start because he thought he could get away with that, it sounds like that's what he might have gotten, which is a drag.
Did he replace any other parts at all?
If not, my guess is his approach of just putting in new rings and reassembling it is faulty and is the likely cause of the problems he now faces.
Time to do it correctly, I'd bet.
He can at least check the cam timing and make sure all the timing marks line up correctly, on the cams and head and the crank and engine cases.
I'd bet he made some mistakes in not replacing needed parts and on reassembly.
Good luck!
The rings were busted already and i really doubt he replaced anything else or oiled it and i know he went for cheapest fix and now hes trying to unload it for $250 on me and it sounds like more work than i need
Hmmmm,
As I suspected.
My thoughts for you -- RUN, do not walk, away from this "deal." :)
Way more trouble than it is worth and it will cost you far more than you think to fix.
Good luck,
Trw
(http://webzoom.freewebs.com/wa6dij/anchor-medium.jpg)
Ugg. I'll buy nearly any condition bike *but* that kind.
What kind?
The kind where someone that knows just enough about motors to be dangerous goes through the bike first, and it still isn't quite right when he's done. I never know what they purposefully hid or what they did out of ignorance and buried deep under layers of cast alumunum, nuts and bolts. There's usually something grieviously wrong with them, and they're always missing bolts and small, annoyingly hard to find parts.
I'd rather buy a bike, lying in a field covered in mouse dung, where the owner thinks it might have run when it was abandoned. At least then I know what I'm buying and can price accordingly.