New to site! Chrysler 120hp problem

[Gartanic]

Hello all!!! I am new to the site but have been readin alot and this place ROCKS!!!!!
Ok, so here I go with my first question! I have a 1973 chrysler 120hp outboard .I just bought the engine,it had 140+ compression on all four cyl. mounted it on my boat , replaced lower unit oil, and took lower unit off to inspect and change impeller. I had water pukin out the 2 pot holes in the backlike I was told it was supposed to. The motor started sweet!! Idled great !! Took it out to the local lake and started right up Ran it aruond for a little bit at no more than half throttle, Finally I cranked it up and it was running very strong. Turned it off and on a few times and had no problems.Running back across the lake to head in at about 3/4 throttle it dies and will not re-fire. The next day it started up but I had to keep the throttle up it would not run at an idle. Checked compression again to find my #4 cyl.had dropped to 40psi. Just took the head cover off and found #2 and #4 cyl. were dry,and #4 has aluminum build up in the sleeve(not scored).I'm lost!! Is it worth it? How much to fix? or just get another motor? Anything would be greatly appreciated!!

 

[Frank Acampora]

Re: New to site! Chrysler 120hp problem

Pistons are around 90-150 bucks each depending upon brand. #4 cylinder needs to have the aluminum scraped off and then honed. It needs a replacement piston. #2 may or may not. If it still has good compression and the cylinder shows no signs of scoring or aluminum deposition, then it will be OK.

Did you put oil in the gas? 1 pint oil per 6 gallons?

Lean running carbs will cause dry cylinders and aluminum throw-off or detonation. so, you need to check the setting on the low spped mixture adjustment needle.

It is not cost effective to have a marina or mechanic do the repair. If you are not afraid of getting your hands dirty, then the repairs are relatively simple and you can save a lot.

 

[Gartanic]

Re: New to site! Chrysler 120hp problem

thanks Frank!!! I can get down right dirty if it means fixing my problem and gettin on the water!! I think I'll go for it! Thanks for the info !!!!!!!!!!