1973 Starcraft 120 hp meecuirser inboard no spark

[BigOs]

Running Bad Evinrude 150

HELP! I have had a summer I don't want to relive with my boat. I have an Evinrude 150XP, (STLCEM), and have been chasing chasing issues all summer. After getting it out of the shop, thinking it was ready to go, I can't get the motor over 2800RPMS, without the motor sounding like it was missing and not opening up any further. NOW, since coming out of the shop, it starts better and easier than EVER before, but still runs like crap.

Today, I finally did a compression check, and I can't believe that it was correct but was only testing at 30psi, and each time I would recheck it, it tested worse. Please tell me I did the compression test wrong.

Last year the boat ran...alright. The only thing I changed last year from years previous, was I began to use a 10% ethenol blended fuel with additives to "help" prevent the fuel from causing issues.

I am fearing a rebuild in the future and afraid of the expense on this old of a motor.

Help and suggestions please.

 

[GA_Boater]

BigOs

Posting an anciet thread won't get you help. Read the Help Tip on top of the page.

You did the compression test wrong. If you say how you tested, maybe you did it right. :smile:

It ain't the E10.

 

[ondarvr]

E-10 isn't much of a problem.......except when you first switch from E-0.

The ethanol will break down all the gunk in the tank and fuel lines that the E-0 left behind for decades, this gunk can plug things up for the first little while, and by the way, there is no miracle in a can that prevent it. I'm not saying this is the actual problem, but frequently is after the first tank or so.

​Have you tried to use the choke or squeeze the primer bulb to see if it runs better, or checked for spark at those RPM's

​It won't run with only 30 PSI of compression, so the gauge or method is suspect. It could run with a couple cylinders at that level, but not all of them.

 

[BigOs]

Rented a compression tester from O'Reillys. I tried to warm up the engine, but it was still running and I idling rough. I tried pulling all the plugs out and testing one at a time. I tried with the plugs in, and tried pulling out one plug at a time. At first the psi was over 30, and as I re-tested each cylinder, the psi's eventually dropped below 30.

Is there a special tester I should be using for an outboard?

 

[boobie]

Take it back to the shop and have them do a compression check.

 

[Putch]

Re: 1978 Mercruiser 140 no spark

Gentlemen, thanks for all of the help. After reading the posts and following the link to the adult section, I pulled the cap and after checking the points again, figured I would clean them with some sand paper just for the heck of it. They were installed new in January 2014. I then bumped the engine over and had strong spark. I put the cap back on and the engine fired right up. Thanks for all the help. Now on to removing and draining the gas tank and confirming the engine will cool.

Where did you find the points? To buy. I have a 1974 Starcraft 120 hp mercuriser inboard I don't have one of them red key fobs. Not sure if I'm suppose to. The person I bought mine from hacked the wires just fixed most of it but I have no spark. And co fused on how to work on this thing coil pack new new fuel lines fuse panels wires new. It don't have a stero anymore. But I'm getting fisterated with it.

 

[Putch]

Please help. Just redid most of the wiring of the boat besides main harness. But I have no spark not sure how to check points but plate is dirty and can't find a link where to buy them. It cranks gets gas just no spark. Has a new coil pack. Please help

 

[Bt Doctur]

Where did you find the points? A GOOD auto parts store, Chevy 230cu inch 6 cylinder
1 install new points and set the gap to .018 on the high side of a lobe
2 make sure you have 12v at the + side of the coil