Engine wont start after rebuild .030 over

[davidkgt]

Just rebuild the engine on my 1990 johnson 70 hp. Tried for abount a half hour trying to get it going. Just wouldnt start. it was close a few times. Any tips, or things I should do the first time starting after a rebuild?

 

[sterndrive tech]

Re: Engine wont start after rebuild .030 over

check fire. all plug wires must have spark,, spray gasoil mixture str8 into throats of carbs to see if fuel is the problem, wrong pistons can be shorter, and cause compression to only be half of whatn we need

 

[nwcove]

Re: Engine wont start after rebuild .030 over

have you done a compression test after the rebuild?

 

[davidkgt]

Re: Engine wont start after rebuild .030 over

Have not done a compression test yet. will do tomorrow and post results. And ill try spraying fuel in, but after trying to start it for awhile there appeared to be excess fuel coming out the carbs. I noticed it seemed close to starting when I was not priming it.

 

[davidkgt]

Re: Engine wont start after rebuild .030 over

Another thought I just had was when I filled the gas tank before we went out it over flowed out of the tank vent. Is it possible that the tank not venting could cause this?

 

[GA_Boater]

Re: Engine wont start after rebuild .030 over

Tank venting will cause the engine to stop after it runs a while. As long as fuel is in the carbs from priming it would start and run until the fuel pump can't suck fuel from the tank because of bad venting.

Do you have spark? That would be my first check because it's easy to miss a wire or even mis-wire.

 

[nwcove]

Re: Engine wont start after rebuild .030 over

fuel running out of carbs? its flooding.....did you overhaul the carbs? id try unhooking the fuel tank and feeding it a few drops of fuel/oil mix in each plug hole.....it should kick and make a very short run.

 

[davidkgt]

Re: Engine wont start after rebuild .030 over

i did try putting a little mix in each plug hole, it didnt do much. As for wiring its pretty straight forward, all the plugs are unique and and lose wires were marked. I will check spark on all cylinders

 

[davidkgt]

Re: Engine wont start after rebuild .030 over

Okay I got it started today. Turns out I forgot to tighten down the reeds on the intake. Fired right up after that. Seems to run a little rough though. I did do a link and sync and thought that I had it pretty good. Tried adjusting needle valve both ways and didnt really help. Not too sure what to try. I just dont want to do any damage if something isnt working right.

 

[davidkgt]

Re: Engine wont start after rebuild .030 over

Also checked compression
109
109
110