1966 Ski Twin coughing/sputters at idle

[gwoloshyn]

Hi folks, I'm trying to run my ski twin but I get a rough idle and it's hard to start. I recently rebuilt the carb thouroughly and am running fresh gas. Fuel pump looks fine. Some may say it could be a lean issue but the motor is throwing lots of smoke. Could this be a possible ignition issue? I have not tried replacing the spark plugs or any ignition components.

Motor is coughing/sputtering at low idle.

 

[Daviet]

Re: 1966 Ski Twin coughing/sputters at idle

Is the low speed needle set properly? Have you checked the compression and spark?

 

[bernd64]

Re: 1966 Ski Twin coughing/sputters at idle

sounds like a carb setup for me.( as Davet say check you low speed needle)

 

[gwoloshyn]

Re: 1966 Ski Twin coughing/sputters at idle

Daviet, compression and spark are both good. I believe my low speed setting is at 1.5 turns from close. I will play with this and see what I get. To help you guys possibly better diagnose the problem, I found a video of my exact same issue on youtube.

http://m.youtube.com/index?desktop_uri=/&gl=US#/watch?v=IozvLtLN3Jg

Any ideas?

 

[Daviet]

Re: 1966 Ski Twin coughing/sputters at idle

Link doesn't work for me, no outboard.

 

[kfa4303]

Re: 1966 Ski Twin coughing/sputters at idle

Have you ever had her running? If the carb is ok, and the compression is good (over 65psi in each cylinder and within +/- 10% of each other), then I would check the ignition. Get a gap spark plug tester and see if your spark can jump a 1/4" gap. If not you'll want pull the flywheel and clean/reset the points, although I would just replace them and the condensers while you're there. You can get a tune up kit for about $25 and you won't have to worry about it again for years. Set the points to .020" and use Champion J6C spark plugs. New copper core spark plug wires help a lot too and are super cheap and easy to replace. Here's a link on setting up your carb needle settings it may help some.

http://forums.iboats.com/showthread.php?t=167352