74 70hp evenrude

[schnarr]

Hello from ontario;

i just bought a 15ft mustang bowrider has a 74 70 hp rude on it hasn't ran i 4 years was kept in a garage all 4 years it. Started up after about 3 cranks idle comes up with the idler on the control box, but when its in the water it will troll along fine but when i go to bring it up it boggs down and dies out, tried new plugs, i tried new fuel tank, i tried new fuel line, checked the screen and fuel filter area all clean, tried running carb cleaner threw it when i spray the bottom carb idle comes up when i spray the top 2 idle dies down but dosn't stall. i took it out to see if i could just drive it out after about half an hour it died and it wouldn't start without the choke and when i tried to put it in gear it would die immediatly, had to get towed home ..... it sucked. Things i want to try cleaning cards/rebuilding (last resort i dont want to bother with trying to re sync them all) OR .... does this motor have points if so i was wondering if they were screwed up? i can't see it though since the owner (close friend) said it ran perfect when it was put away.

any opinions on this matter would be helpful im itching to do some cruising.

thanks
Matt

 

[Rudy Brown]

Re: 74 70hp evenrude

Sounds like its time to rebuild the carbs. The bottom one sounds like its starving for fuel. If you run it long enough, it'll ruin the bottom cylinder from lack of oil.

 

[jtexas]

Re: 74 70hp evenrude

A 2-stroke motor gets its lubrication from the oil you mix with the gas. When you spray carb cleaner into a running engine, what you are doing is stripping out the oil that might have been there. What you have then is metal on metal, no lubrication, moving at hi-speed, I don't want to be there when it burns up.

Instead of carb cleaner or starting fluid, use premixed oil/gas in a spray bottle.

What you have here is a classic symptom of fouled carbs. Gasoline turns to varnish and clogs the tiny passages. Like Rudy says, rebuild is the only solution.

Disassemble, soak overnight in carb cleaner, blow out passages with compressed air (or aerosol carb cleaner), reassemble with new carb kits. You have fixed jets, so there's no adjustments. Don't fret bout the link & sync - if all you do is remove & reinstall carbs, shouldn't need more than just making sure the throttle plates are parallel, start out closed and end up horizontal, and that the throttle cam hits the roller right on the mark. And that the choke plates are open except when engaged at which time they should be fully closed. Anyway, she's not going to run til that gets done.

No points on that motor - why do you suspect ignition? have you done a spark test?

You're going to want a repair manual - Seloc is ok but the factory shop manual is better, try kencook.com

p.s. - champion QL77JC4 gapped at .030 - just say no to NGK

 

[schnarr]

Re: 74 70hp evenrude

thanx is there a online site where i can get parts for this old beast?

 

[BoatBuoy]

Re: 74 70hp evenrude

You can get service parts/seals here at iboats. Internal engine parts you can get at ishopmarine.com.