1988 merc 150xr4

[starcraft1982]

ok,im almost ready for the first run of my recently purchased cajun bass boat.had compression checked,122,120,121,122,121,125.electric also checked fine.unhooked oiler,replaced impeller,drained old gas and put new premix in.so,anything else i shoud check out before hitting the water?i know temp guage does not work yet so besides impeller/waterpump,is there any other possibility of overheat?boat sat 5yrs.thermostats?i figure w/nothing to gunk up like on a car,should be ok.just dont want to damage this motor.thanks.also what is range of proper operating temp?i already ran on muffs,fyi.idled good,started quick(no cranking)

 

[CharlieB]

Re: 1988 merc 150xr4

Two things

When you said the electrics check out fine, does that mean that you checked spark on ALL cyl's and EACH has at least 7/16 bright blue sharp Crack??

A dead cyl is easy to miss on the hose when there is no load on the prop.


Second, fuel system,

While it may run fine on the hose, are the main jets CLEAN so you do NOT go lean at WOT??????

Do a search here on Awakening a sleeping engine

You should find a whole list of pre-flight's to check out.

 

[starcraft1982]

Re: 1988 merc 150xr4

i had a mechanic come and do all work for me.all i know is that he hooked to each cylinder and as i turned over motor he wrote comp.readings and couple other things on his paper.when all six were checked he said comp. was fine and electrical checked fine.then he ran it.he did tell me there was possibility for problems when on water,but as good as it checked out and sounded he didnt expect any issues.i know there are possible issues,and will have full trolling batteries at the ready.also he suggested to do a "mini break in"which i will do.1/4 trottle 3 mins.,1/2 3 min.,3/4 3 min,back to1/4 3 min,1/2 3 min.,then full.my main issue is temp since temp guage doesnt work(i will be replacing).water stream was fine after impeller replacement and pump inspection.just would like to know if there are other possible culprits to overheating i should check/replace since i cant watch temp guage.

 

[j_martin]

Re: 1988 merc 150xr4

After sitting that long it would be well worth your while to put a kit in the fuel pump.

If, on the lake it balks or backs off at all at WOT, back out immediately and go fix it. That's a fuel delivery problem and is about the most reliable way to burn this engine down.

Other than that, it's a rock solid reliable engine that goes like a scalded dog.

hope it helps
John