Ran great on land now won't start!!

[Ryan Davidovich]

Got a 1975 70hp Johnson. Just got starter rebuilt, put new starter solenoid on and a new rectifier on. Started the engine in my driveway, with start lever up. It started better then it ever had before. Let it warm up, put the start lever back down to idle and engine idled great, no sputter or sounds of being choked off or out of fuel, motor ran fwd and reverse great in the driveway. Go to lake and launch boat. Motor kicked over great with the start lever up, let warm up, put start lever to idle and the engine cut out. After a few times the engine seemed to flood and after holding the key in the start position, it started to puff out smoke like it was clearing out the flood, and it kicked over again. Then it eventually just stopped firing. Almost like it flooded again. During all this time I made sure the fuel flow was going through the ball and had good pressure.
But no matter how long I idled the engine on the water everytime I put it in gear fwd or rev or lowered the start lever back to idle it would cut off.

Any Suggestions?

 

[papyson]

the low speed jets need adjusting....you have exhaust back pressure when in the water and none on the hose....

 

[racerone]

I think it has fixed low speed jets ----No adjustment on them.----------Have to change the jets in order to change the mixture.

 

[KingCanadian]

the low speed jets need adjusting....you have exhaust back pressure when in the water and none on the hose....

Would one only be able to figure out the exact adjustments thru trial and error?

 

[Boobie]

Do a compression check on it and then a cyl drop test on it to make sure it's running on all the cyl's.