Low Compression
Thread Starter
|
Stage II
Joined: Mar 2013
Posts: 2
Likes: 0
From: kansas city
Low Compression
Help! I just put my motor together, I have a 2009 street glide that I put a 106 inch S&S big bore kit, S&S 585 EZ START cams, S&S adjustable pushrods, and had a S&S port and polish on the stock heads. Valves are set up for 585.
The bike starts, BUT I have 95 PSI in the rear cylinder and 150 in the front. I tore it back down, and checked the rings, nothing, checked the cylinder walls for gouges, nothing, checked the new valve job for leaking (solvent on top of the valve), installed new gaskets, and still 95 PSI in the rear and 150 in the front. I put about an ounce of oil in the rear cylinder and the comp cam up to 150, and then back down to 95. Sounds like ring issues?? Could my brand new cylinder, piston and rings have a issue from the factory? What do I do, I am at a loss???
The bike starts, BUT I have 95 PSI in the rear cylinder and 150 in the front. I tore it back down, and checked the rings, nothing, checked the cylinder walls for gouges, nothing, checked the new valve job for leaking (solvent on top of the valve), installed new gaskets, and still 95 PSI in the rear and 150 in the front. I put about an ounce of oil in the rear cylinder and the comp cam up to 150, and then back down to 95. Sounds like ring issues?? Could my brand new cylinder, piston and rings have a issue from the factory? What do I do, I am at a loss???
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,586
Likes: 6,435
From: Honah Lee
I guess you are opening throttle wide open when checking since you have one good one. I think why the compression came up was an ounce of oil. That's a lot of oil. Lock the motor with rear piston at top dead center on the fire stroke in low gear. Remove air filter and attach air hose to spark plug hole and listen for the air. You should not hear leaks in intake or exhaust. Could you have the pushrods too tight (long)
Last edited by Jackie Paper; Mar 7, 2013 at 08:00 PM.
Intermediate
Joined: Feb 2013
Posts: 30
Likes: 0
From: Macon
Trending Topics
Advanced
Joined: Mar 2013
Posts: 65
Likes: 2
From: CENTRAL IL
I confirm cam chain not aligned sounds proper to me but what do I know im just a Harley tech lol...
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Thread
Thread Starter
Forum
Replies
Last Post