Boats For Sale:
Compression Test Results - Need Advice |
Post Reply 
|
| Author | |
a0128 
Senior Member 
Joined: May-05-2014 Location: Oregon Status: Offline Points: 226 |
 Post Options
 Thanks(0)
 Quote Reply
 Topic: Compression Test Results - Need AdvicePosted: May-14-2014 at 3:32pm |
|
Looking to buy a 1999 Pro Air. GT-40 engine with 501 hours. Maintenance history unclear. Compression results (cold and dry engine) are as follows:
#1 120 #3 100 #5 125 #7 124 #2 110 #4 134 #6 145 #8 133 Looking at the numbers I am worried about #2 and #3. Could these reading indicate a possible head gasket leak, worn valves and / or rings? Or are these numbers typical for a 15 y/o engine with 501 hours. Thanks in advance for your feedback. |
|
 |
|
|
mark c
Gold Member 
Joined: May-09-2012 Location: Massachusetts Status: Offline Points: 534 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 4:13pm |
|
To tell if its worn rings you have to put a tablespoon of oil into each cylinder and do the test over again to see if the readings improve. Don't forget to hold the throttle blades wide open while doing thes test. cylinder leakdown test may be able to differntiate between rings and a burned valve or two. But 2 & 3 are next to each other in the center of the cylinder bank so theres a fair possibility of a bad head gasket between the two of them but you need more testing before jumping to that conclusion.
|
|
|
|
|
backfoot100
Platinum Member
Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 4:29pm |
|
Personally, I wouldn't hesitate to buy it purely based on those numbers. Considering a compression test should be done hot and I assume it has been sitting for a while (the reason for running the numbers cold). I think those numbers are pretty good. Even if those were the numbers done hot, I wouldn't hesitate to buy it.
Why couldn't it be started? |
|
|
When people run down to the lake to see what's making that noise, you've succeeded.
Eddie |
|
|
|
|
a0128
Senior Member
Joined: May-05-2014 Location: Oregon Status: Offline Points: 226 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 4:39pm |
|
According to the dealer the boat runs well. Boat is in Nevada, I am in Oregon so I want to make sure my trip down there is not wasted on a boat with a potentially bad motor.
|
|
|
|
|
backfoot100
Platinum Member
Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 4:50pm |
|
Where in Nevada? I'm guessing one of our members here would be happy to at least go give it a once over before you make the trip.
It's been done a lot more than you would think already. All you have to do is ask. |
|
|
When people run down to the lake to see what's making that noise, you've succeeded.
Eddie |
|
|
|
|
JoeinNY
Grand Poobah 
Joined: October-19-2005 Location: United States Status: Offline Points: 5693 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 5:29pm |
I wouldn't either... |
|
|
|
|
a0128
Senior Member
Joined: May-05-2014 Location: Oregon Status: Offline Points: 226 |
Post Options
Thanks(0)
Quote Reply
Posted: May-14-2014 at 7:53pm |
The boat is at Boulder Boats in Henderson. If there is a member in that area willing to look at it for me please PM me. Much appreciated! |
|
|
|
|
Post Reply
|
|
Tweet
|
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
Topic Options
backfoot100 wrote: