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Author Topic:   Compression Testing

lizard posted 10-16-2008 10:38 AM ET (US)
What tools are required to perform compression testing on a V6 Evinrude, circa 90's? Is this something the average individual with a hands on background to some auto maintenance can do? What are ideal readings for a motor like this?
Thanks, in advance, for any input!
Tohsgib posted 10-16-2008 11:09 AM ET (US)
Depends on the year but anywhere from 90-110 seems to be the norm. Guage accuracy varies as well. So my gauge might read 95lbs and yours might read 85lbs. Go to ANY autoparts store and for $25 you can buy a tester. Remove all the plugs, screw it in to a hole and have somebody turn it over a few seconds until needles stops going up. Write it down and move on to the next hole. All holes should be with 10% or so. Make sure you remove the safety lanyard so the wires do not spark.
lizard posted 10-16-2008 09:14 PM ET (US)
From your response, it would appear that I do not need muffs on the boat, with water supply, to check the compression.
I suspect that the motor might be a Ficht. Other than the known concerns with some Fichts, is there anything else I should look for besides the lower end oil?
thanks.
jimh posted 10-16-2008 09:44 PM ET (US)
A procedure for performing a compression test is described in my article
Assessing Used Outboard Motors
http://continuouswave.com/whaler/reference/outboardCheck.html
jimh posted 10-16-2008 09:45 PM ET (US)
To assess a used outboard, see the recommendations in my article
Assessing Used Outboard Motors
http://continuouswave.com/whaler/reference/outboardCheck.html
Peter posted 10-17-2008 07:32 AM ET (US)
Exactly what model Evinrude V6 are you looking at? You will not be running the engine when you are doing a compression check so there is no need for muffs.
If it is a Ficht, then it would be wise to have a qualified technician take a look. The technician will be able to plug a laptop into the EMM and determine what trouble codes have been set, how many hours the motor has been run and how the engine has been run over those hours.
Tohsgib posted 10-17-2008 12:36 PM ET (US)
If it is a ficht evinrude then 1999 or newer. So when you say circa 1990's are you sure it is a ficht? If it is a 1999 it better be darn cheap and if a 150-175 I would basically want it for free.
Blackduck posted 10-17-2008 04:58 PM ET (US)
The engine should be warmed up to normal operating temperature before doing a compression test.
jimh posted 10-17-2008 05:29 PM ET (US)
Re engine temperature for compresssion testing--this is mentioned in the article I suggested above.
lizard posted 10-17-2008 10:34 PM ET (US)
Many thanks for the responses. I got an email tonight that the boat went to another buyer. However, I will keep the links inserted above, as a reference for if/when the next opportunity arises.
Thanks again.

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Author	Topic: Compression Testing
lizard	posted 10-16-2008 10:38 AM ET (US) What tools are required to perform compression testing on a V6 Evinrude, circa 90's? Is this something the average individual with a hands on background to some auto maintenance can do? What are ideal readings for a motor like this? Thanks, in advance, for any input!
Tohsgib	posted 10-16-2008 11:09 AM ET (US) Depends on the year but anywhere from 90-110 seems to be the norm. Guage accuracy varies as well. So my gauge might read 95lbs and yours might read 85lbs. Go to ANY autoparts store and for $25 you can buy a tester. Remove all the plugs, screw it in to a hole and have somebody turn it over a few seconds until needles stops going up. Write it down and move on to the next hole. All holes should be with 10% or so. Make sure you remove the safety lanyard so the wires do not spark.
lizard	posted 10-16-2008 09:14 PM ET (US) From your response, it would appear that I do not need muffs on the boat, with water supply, to check the compression. I suspect that the motor might be a Ficht. Other than the known concerns with some Fichts, is there anything else I should look for besides the lower end oil? thanks.
jimh	posted 10-16-2008 09:44 PM ET (US) A procedure for performing a compression test is described in my article Assessing Used Outboard Motors http://continuouswave.com/whaler/reference/outboardCheck.html
jimh	posted 10-16-2008 09:45 PM ET (US) To assess a used outboard, see the recommendations in my article Assessing Used Outboard Motors http://continuouswave.com/whaler/reference/outboardCheck.html
Peter	posted 10-17-2008 07:32 AM ET (US) Exactly what model Evinrude V6 are you looking at? You will not be running the engine when you are doing a compression check so there is no need for muffs. If it is a Ficht, then it would be wise to have a qualified technician take a look. The technician will be able to plug a laptop into the EMM and determine what trouble codes have been set, how many hours the motor has been run and how the engine has been run over those hours.
Tohsgib	posted 10-17-2008 12:36 PM ET (US) If it is a ficht evinrude then 1999 or newer. So when you say circa 1990's are you sure it is a ficht? If it is a 1999 it better be darn cheap and if a 150-175 I would basically want it for free.
Blackduck	posted 10-17-2008 04:58 PM ET (US) The engine should be warmed up to normal operating temperature before doing a compression test.
jimh	posted 10-17-2008 05:29 PM ET (US) Re engine temperature for compresssion testing--this is mentioned in the article I suggested above.
lizard	posted 10-17-2008 10:34 PM ET (US) Many thanks for the responses. I got an email tonight that the boat went to another buyer. However, I will keep the links inserted above, as a reference for if/when the next opportunity arises. Thanks again.