Evinrude rebuild

mrbell83

mrbell83

Petty Officer 2nd Class
Joined
Oct 23, 2005
Messages
148
Anyone out there know how much it costs / how hard it is to rebuild a 9.5hp Evinrude? It runs now, but with low compression.<br /><br />Thanks, Chris
 
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TimMattson

Seaman
Joined
Nov 13, 2005
Messages
69
Re: Evinrude rebuild

Chris ,<br /> Low compression on one? or both low and the same # can mean simply a head gasket leak.Taking off the head will reveal either minor scuffing,bad gasket between the cyl. or a broken ring.The cost to repair varies based on condition of Crank,block and what caused it....Cooling should be new,carb should be rebuilt,and the lower unit needs to be free of water in the oil.Each of these are $150.00 jobs so maybe a matching motor with good compression( #1 )would be the cheapest way to go.We rarely can do these without going to $1000.00 all.With a new one being not uch more ,Id look for a used powerhead and do a swapout.<br /> Tim
 
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Bradster941

Petty Officer 1st Class
Joined
Mar 4, 2003
Messages
203
Re: Evinrude rebuild

Chris, if you are interested in doing it yourself, then perhaps you have the perfect project engine to start on, (assuming it is less then 30 years old).<br /><br />First things first. Buy the manual and read it thoroughly ! Available here at Iboats.<br /> <br />Please post the year, model and serial number, of your OB. and the current compression readings.<br /><br />As for cost, it could be as simple as buying;<br />Gasket kit $45.oo<br />Rings $12.oo<br />Misc. sealants $25.oo<br />Cross hatch tool $30.oo<br /><br />Now, before you get too excited about that price, doing a job right includes a bit more on a rebuild.<br /><br />a) rebuild the carb.<br />b) rebuild the water pump<br />c) change lower unit lube, reseal if necessary. <br /><br />Also, while tour down, you will want to have a machine shop check the cylinders for size and trueness. If excessive ware has occurred, then the block will need to be bored and resealed, about $250.oo generally and you may have to replace the pistons, $100 to $180.<br /><br />Tim Mattson has it right on what needs to be done and the cost if you have a shop do it.<br /><br />But if you do it yourself, even if you have never tried something like this before, when you finish, your investment will be paid back many times over in Satisfaction the first time you fire ‘er up !!!! <br /><br />It’s really allot of fun to tear them down and put them back together. ;)
 
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Bradster941

Petty Officer 1st Class
Joined
Mar 4, 2003
Messages
203
Re: Evinrude rebuild

Chris, if you are interested in doing it yourself, then perhaps you have the perfect project engine to start on, (assuming it is less then 30 years old).<br /><br />First things first. Buy the manual and read it thoroughly ! Available here at Iboats.<br /> <br />Please post the year, model and serial number, of your OB. and the current compression readings.<br /><br />As for cost, it could be as simple as buying;<br />Gasket kit $45.oo<br />Rings $12.oo<br />Misc. sealants $25.oo<br />Cross hatch tool $30.oo<br /><br />Now, before you get too excited about that price, doing a job right includes a bit more on a rebuild.<br /><br />a) rebuild the carb.<br />b) rebuild the water pump<br />c) change lower unit lube, reseal if necessary. <br /><br />Also, while tour down, you will want to have a machine shop check the cylinders for size and trueness. If excessive ware has occurred, then the block will need to be bored and resealed, about $250.oo generally and you may have to replace the pistons, $100 to $180.<br /><br />Tim Mattson has it right on what needs to be done and the cost if you have a shop do it.<br /><br />But if you do it yourself, even if you have never tried something like this before, when you finish, your investment will be paid back many times over in Satisfaction the first time you fire ‘er up !!!! <br /><br />It’s really allot of fun to tear them down and put them back together. ;)
 
mrbell83

mrbell83

Petty Officer 2nd Class
Joined
Oct 23, 2005
Messages
148
Re: Evinrude rebuild

Well the motor is a 1971 9.5hp Evinrude.<br /><br />The compression in both cylinders is 75 and thats cold, and I can assure you that there is a ton of carbon buld up in this motor, the org owner was very mean to her.<br /><br />If I were to decarbon it with some seafoam (how would be nice) do you think that may restore my compression so I don't have to rebuild, at least for a while?<br /><br />Thanks everyone, let me know, after all I am just a cadet. ha.
 
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Walker

Captain
Joined
Jun 15, 2002
Messages
3,085
Re: Evinrude rebuild

Is it a rope start motor. If so then a de-carb is what to do first. My rule of thumb on a rope start motor is if it will start then you have enopugh compression.
 
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TimMattson

Seaman
Joined
Nov 13, 2005
Messages
69
Re: Evinrude rebuild

Hello Chris ,<br /> My main point wasnt scare you out of this job,just make sure you dont buy a bunch of stuff ,only to find out your crank is bad or the block is mucked up someplace important.<br /> 75 psi is pretty low to expect results.<br /> Use engine tuner on a regular basis when you do get running,(fresh plugs every 50 hrs right after a de-carbon treatment).This involves shooting the stuff into your carb on a warm engine.Run it until a nice blu cloud pours out and then stuff a little more in as it dies.....let it sit 15 minutes and then run the pants off it,preferably on the water.Carbon is your enemy so dont use cheap oil.<br /> Goodluck!<br /> Tim M
 
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rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Evinrude rebuild

you will find that motor is normally a junker, most of the parts are NLA. may be fun to play with though. the 9.5 is about the hardest one to learn on. moreso if its ever seen salt. buy the factory manual as the aftermarket ones dont describe that old turrtle back in enough detail.<br /> before delving into it to much check the ign and fuel systems, if both cyl are at 75 psi I would run it. a decarb or two may not hurt.<br /> if there is any doubt for cyl wall condition its not to hard to pull the cyl head and have a look.
 
mrbell83

mrbell83

Petty Officer 2nd Class
Joined
Oct 23, 2005
Messages
148
Re: Evinrude rebuild

Thanks for all the help guys, I will do it all and post the results here in the next few days.<br /><br />It may be a junker but I am learning allot on it!<br /><br />Thanks again,<br />Chris<br /><br />mrbell83@hotmail.com
 
mrbell83

mrbell83

Petty Officer 2nd Class
Joined
Oct 23, 2005
Messages
148
Re: Evinrude rebuild

Ok guys, does this make sence, I followed the decarbonize instructions to a tee, then after I restested the comp with the motor nice and warm, the compression was actually 70psi in both cylinders, that's 5 psi lower than when it was ice cold?<br /><br />What are your thoughts on this?
 
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rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Evinrude rebuild

yep<br /> makes sense.<br /> thats why no spefic numbers are posted just the range from highest to lowest.<br /> if your concerned with the sealing ability have a leakdown test performed. its a definitive go no go test unlike a compression test.
 
mrbell83

mrbell83

Petty Officer 2nd Class
Joined
Oct 23, 2005
Messages
148
Re: Evinrude rebuild

Ok, how do I go about doing a leak test? Or is this something I need to have a service shop do?
 
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