Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

How much is to much compression?


mciecko's Avatar
Member

Join Date: May 2014
Posts: 8
WI

05-28-14, 06:38 AM   #1  
How much is to much compression?

I've read quite a few times on here that the best way to check compression is with a leak down tester, unfortunately I don't have one at this time. My question is how much compression is to much on a small engine on a riding lawn mower. The one that I am working on now is a 16hp Briggs Vanguard 303777-1114-E1 that's reading 160 psi on one cylinder and 170 psi on the other, which seems to be a lot higher than I've seen.

 
Sponsored Links
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

05-28-14, 09:45 AM   #2  
That's a high reading... are you having problems starting it? Have the valves been adjusted?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
mciecko's Avatar
Member

Join Date: May 2014
Posts: 8
WI

05-28-14, 09:52 AM   #3  
It starts pretty normal actually. The only issue is when pushing the throttle from idle to full throttle there's just a bit of black smoke from the exhaust just for a second.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

05-28-14, 09:58 AM   #4  
That's fairly normal for that engine. I'd adjust the valves and use it. Those engines are top of the line... you won't find much anything better.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
mciecko's Avatar
Member

Join Date: May 2014
Posts: 8
WI

05-28-14, 10:02 AM   #5  
Thanks for the input. What are the basic steps to adjusting the valves?

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

05-28-14, 10:06 AM   #6  
Turn the engine to TDC on the compression stroke, then 1/4" past tdc and set the valves on that cylinder to .005" with a feeler gauge. Repeat with the other cylinder as well.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
mciecko's Avatar
Member

Join Date: May 2014
Posts: 8
WI

05-28-14, 10:37 AM   #7  
Thanks for the information and help

 
Search this Thread