new motor, stalls, performance questions

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Andrew04

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Hey Guys, I just got a 1970 Johnson 9.5 horse outboard for my 14' semi-V. First issue was i was only able to go 9.2 MPH on gps, so I was a little disappointed seeing as my 5hp pushed me 6.2mph. The engine appears to run like it should, so I doubt a tune up will regain any ponies. After wasting some gas it suddenly comes to a complete stop, as if fuel wasn't being delivered. bulb has hard, no leaks. I am wondering if it needs new fuel lines because of ethanol eating away at them? is there anything I should look for?

Thanks in advance, I will keep everyone informed as I progress. Thanks! -Andrew
 
only thing I can think of is maybe the fuel lines are colapsing and maybe the connection at the motor for the fuel line. No expert here but if it is stalling at full fuel flow maybe there is not enough getting there?
 
Hi andrew
Posted earlier my findings on ethenol and problems it causes. Are you running premium fuel ? Could well be that your lines have collapsed under open throttle. Try new fuel.
Buff
 
If you take the time to replace the lines get on google and find a local oil company that sells non ethanol premium. I use Almond oil company because its local, only .10 cents more than that ethanol crap and small motors just plain run better on it.

My fathers roadking, my 115hp merc SeaPro, my 25hp merc mirrocraft, sthil chainsaw, weed eater... If its not on the road on four wheels you're dang sure it's non ethanol with me.
 
Thanks for the help, I was afraid of that. I will get new lines then use ethanol free fuel. Thanks!
 
lovedr79 said:
Make sure tank vent is working. Engine will idle and free rev but feels weak under load

If the vent wasn't working the bulb wouldn't be hard it would suck down from the engines pull for fuel
 
Ok, fuel line replaced. I don't know if its a seperate problem, or if I just did a better job diagnosing/observing.Now Engine only runs with choke on. I take this to mean the high speed jet is clogged, and ordered a carb kit.
Any other suggestions?
 
Did you try adjusting the high speed jet on your carb? Possibly opening it up?

Try running some seafoam through the engine if adjusting the jet does not work
 
Hi speed is not adjustable, its simply a fixed orifice plug that comes with the carb kit. Should I try to clean the old one?
 
You could try and clean the old one before you get the carb kit

When you go to do a full rebuild swing by your auto parts store and get a gallon of Chem dip carburetor cleaner and let it soak overnight
 

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