Motor Stalling

Fish_This

Cadet
Joined
Jul 26, 2010
Messages
24
Hi All,

I have been lurking around this website for years and I now am in need of some help.

I purchased a 1993 Wahoo 16.5 Striper this past week and I love this boat. I took it out for its maiden voyage yesterday and it started right up no problem, a little smoke but hey it's a 2 stroke and the guy before me unhooked the VRO System and he has been pre-mixing it for years. O.k. now the Delima :(

The motor is a 1993 70Hp Johnson.

She starts up with no problem idles at around 1k in Neutral, she has a great hole shot and runs great until I put it in idle in gear and then she stalls on sometimes wait about 20 minutes and she starts. Another time she runs great and I turn it off for a 10 minutes then go to start it again and she doesn't want to start. I put the throttle to her and push the key in for choke and it takes alot of cranks but she finally starts and I can run her at WOT and it is great all day long. I went to flush her in the lake (I run it in the South Florida Intracoastal). I figured why not try to reproduce the problem and I was able to, back her down in the water ran it turned it off and on a few times then BAM she doesn't want to start. I look at the primer ball and squeeze it and it seems very soft. Push it a few times it hardened up another 20 cranks with the throttle Wide opened and she starts. Turn it off again and she starts up with no problem. I am ordering a service manual from this wonderful website, but in thee mean time can anyone give me a few troubleshooting tips until it gets here?

I also noticed that it seems the trim doens't want to work unless I slow way down and then I can use the trim again. I am stumped.

Also when I put the key in and turn it to the on position (not to start it) I get a alarm sound for like a second is that normal on these engines?

I do alot of fiberglass work but nor motor work. I really want to get to know this engine inside and out. I look forward to helping you all in the future.

Thanks for anything you can contribute.

Regards
Paul
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Motor Stalling

Start with a compression test and spark test. Spark should jump a 7/16" gap on an inline tester clipped to the engine block. Report your result.

The fuel line needs to hold pressure...after you pump it up in the morning you shouldn't have to squeeze it again.

You need fresh gasoline, and no water or debris in the tank. And make sure the tank vent is open and clear.
Spark plugs should be champion QL77JC4 at .030, in good condition.

Hard warm start, most common cause is flooding -- leaky float valves in the carbs. Are you saying that it dies at idle, and won't restart for 10 or 20 minutes? A warm engine shouldn't need choking.
 
Top