93 15hp evinride driving me NUTS!

[drkilldrmz]

I have had the outboard for about 5 years and it has always been a decent runner, but would never troll quite the way i wanted it to. Recently, it started Bucking and stalling at idle, then would only start again with choke. then drove it back to the launch. Ordered a new carb kit and installed it. The carb is absolutely spotless..with all new kit installed. This is the second time in a year i put a kit in it just to make sure. Now it will only start and run on high throttle, and die quickly under 3/4. Same tank, gas, and hose runs my 73 5 hp johnson without issue. Compression is 120 exactly per cyl. new plugs gapped and installed. Im fairly adept with motors but this one has me flustered. No cracks in the plastic carb cover. Im out of ideas, and was hoping someone has some suggestion before i give up on it altogether. Anything at all would be great!! Thanks.

 

[drkilldrmz]

Bump

 

[racerone]

Trouble shooting starts with a compression test.----Then check for spark that jumps a gap of 3/8" or more on both leads.----After that you start looking at fuel and induction issues.------Report the results of those tests.

 

[buddhapi]

I would definitely check out the fuel filter and pump assembly. you never mentioned that at all, but your screen maybe plugged up. that's why it helped when you put the choke on initially to get back to the launch. your fuel bowl fills up when you pump the ball, but when you run it, it goes fast, and then dies when that fuel is used up.

 

[drkilldrmz]

Compression is exactly 120 per cyl. SPark is bright blue and snappy. I remover the carb line from the fuel pump and pulled it over.. Shoots fuel for a mile. Still stumped?

 

[racerone]

Crankcase compression.----------------------Issue with a reed vave?-------Or possibly the bottom crankshaft seal.

 

[drkilldrmz]

Always like to follow up so.. Brought it in to a mechanic. He was stumped also because everything fuel wise just looked perfect. FInally it was decided to replace the carb altogether with a newer style and it trolls to nothing perfectly and can't be stalled ( reportedly) without the kill switch. He water tested and stated this. Im hoping to get out today if the launches aren't too full to verify this . Apparently the 93 carbs are a bit over engineered and the design was changed. So... somehow was the carb although neither of us could figure out why. Cheers!