Older Mercruiser 120 Rebuild kit?

dezmond

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Jul 21, 2010
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Hey Everyone. I’ve been working on a rehab with my Capri 1750. I am getting closer to starting to clean up my engine and drive. Since the engine has been sitting for a year and a half, I was thinking I should be pulling some of it apart? Not sure how deep I need to go. Could I get some tips and advice on what I should be doing and looking for? Also to prepare myself if and when I do tear it apart, what hardware should I be ordering when I put it back together? Bolts, gaskets, pumps, etc.

Thanks all all for the help. My serial numbers are in my signature. Mid 70’s I believe
 

alldodge

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You just want to clean it up or want to rebuild?
If just cleaning it up, crank it over some to get the oil circulating, then connect ignition and see if it will fire up.
Be good to rebuild the carb so need a kit
 

Scott Danforth

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If it was running good prior, I would not do anything more than the following:
  • squirt oil in the cylinders (WD40 is sufficient), take a compression reading - if all above 120 psi (cold) and within 5-10 psi of each other, the motor itself should be good
  • take the alternator and starter to an alternator/starter shop and have tested
  • pull the carb and go thru it
  • new belts
  • file the points, gap and set the dwell (while cranking)
  • new plugs
  • hose the motor off with engine degreaser
  • wire brush any rust
  • paint as needed and install

if the motor is toast, find a 3.0 liter to replace the 2.5 liter
 

thumpar

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Jun 21, 2007
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I wouldn't get into it much. 3.0l's are pretty easy to find in good running condition and pretty much a drop in replacement for a 120/2.5l. The 120 is a good motor, I had one, but not worth the investment of rebuild. If it needs anything more than basic tuneup stuff I would be looking for a replacement.
 

dezmond

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Jul 21, 2010
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Thanks for the advice guys.. I will do a compression test first off both dry and wet and chime in with the numbers. Also I am going to pull the carb and have it sent to the proper shop to have it rebuilt. I will post pics and results when it comes back. They do a complete tear down, clean, paint, all new parts, and flow test it. Supposed to be able to just drop it back on and go.. We shall see. I will get new oil pan, valve cover, fuel pump and thermostat gaskets along with new plugs, belt and....

I have the pertronix kit already installed so no points to worry about Scott ;)

Again thanks and I will be back with what I get and what I find.
 

dezmond

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Jul 21, 2010
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Oh and of course I will scrub it down and new paint :)
 

Scott Danforth

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The carb on there has about 8 parts. Easier to rebuild than building a console
 

dezmond

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Jul 21, 2010
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The carb on there has about 8 parts. Easier to rebuild than building a console

Very True Scott.. I figured if I pay a pro to do it for $175.00 and it is completely done and ready to go and setup correctly, I should be ok no? This includes all the parts as well needed. If anything is wore out, they replace it.

Not so good of an idea? One less thing for me to do ;)
 

Scott Danforth

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I personally would spend $40, rebuild myself and pocket $135
 

dezmond

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Jul 21, 2010
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I might do that if it only costs $40.00 for a rebuild kit. Thanks for the tip there.. I'm sure I can spend the $135 on other things for the rehab ;)
 

Grub54891

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Jun 17, 2012
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Even having the carb rebuilt by a pro, it still may need tweaking once installed. Had a couple that were re-man's that must have had some rough shipping. The float heights were way off, could not get them to run well. Ended up resetting them myself. They are easy to rebuild. The only reason we get new or re-man carbs is the owners want them. Most others I rebuildmyself.
 
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