Honda GX390 problems


  #1  
Old 11-04-17, 11:05 AM
M
Member
Thread Starter
Join Date: Nov 2017
Location: Finland
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Question Honda GX390 problems

Hi!
I have a problem with my Honda GX390 that I got for free from my grandpa because it needed new pistonrings. Now I've replaced the piston and pistonrings but there is a looot of friction when turning over the engine and it only has 70 psi compression. I've set the valve gap to 6 thou intake and 8 thou exhaust. Headgasket is also new. Bearings feel good and spin freely
What could cause this?
 
  #2  
Old 11-04-17, 11:21 AM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 18,015
Received 109 Upvotes on 99 Posts
Did you check piston ring end gap when you installed them? I assume you properly honed the cylinder and there were no bad spots or gouges?
 
  #3  
Old 11-04-17, 01:48 PM
M
Member
Thread Starter
Join Date: Nov 2017
Location: Finland
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Did not hone since the crosshatch pattern looked good. End gap was .4mm as recommended in the shop manual.
 
  #4  
Old 11-05-17, 01:27 AM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 18,015
Received 109 Upvotes on 99 Posts
The crosshatch pattern is worn down and smooth now, it won't seat in your new parts. It's broken in to the old rings.
 
  #5  
Old 11-05-17, 02:38 AM
M
Member
Thread Starter
Join Date: Nov 2017
Location: Finland
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
As I said, the honing pattern looked good, maybe it was honed before I got it. But yeah I could hone it again just to make sure.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: