another new guy needs some help with 1967 johnson

[scubaken]

Last summer i bought a boat with a 1967 johnson 20hp model# fd 21r,after running all summer the motor started to get hard to start.I replaced the plugs,coils,points,condensors,fuel pump and rebuilt the carb.I finally got around to getting the boat out this year and it starts great but it is running extremely rich.I pulled the carb and checked the float adjustment and let the float sit overnight in a little gas to see if it has a hole by chance,I also sprayed all the holes in the carb with cleaner to make sure all was clear.So this evening i put it back on the motor and tried again and its still smoking and running very rich....any help would be great on what to try next.....thanks

Im also running 50/1 mix for gas and the spark is nice and blue

 

[jimdd810]

Re: another new guy needs some help with 1967 johnson

Is it running rich all the way to wot?

 

[jimdd810]

Re: another new guy needs some help with 1967 johnson

I would try decarbing the engine. I like to use omc engine tuner and follow the directions exactly.

 

[1946Zephyr]

Re: another new guy needs some help with 1967 johnson

Make sure the carb is vented properly too. I had a couple do that. Also, check your float level and make sure it is right.

 

[scubaken]

Re: another new guy needs some help with 1967 johnson

went out and tried it this morning and its rich no matter what speed we are cruising at.The motor did start on 1 pull and idled great!It just looks like the boats on fire cruising across the water.I also put some sea foam in the gas,i guess the next thing is to try the decarbonizer stuff.

 

[Al-53]

Re: another new guy needs some help with 1967 johnson

The sea-foam is a decarbonizer....the can will tell you how to use it as one also...I found that sea foam works as good if not better than engine tuner and cheaper also...tons of posts here on sea foam...

If you have a spare gas tank..put 1 gallon of mix in it...3/4 of a can of sea foam in it...take plugs out...spray the rest in the plug holes..let sit for a hour or 2....then start and take for a run...it will smoke like a house on fire..in the process it is de carbonizing the engine...run the whole 1 gallon out....then switch to a tank of just mix and run it again ..you now just de carboned the motor...

now add sea foam to every tank of gas to keep the motor clean...

there is a post here how to do it also..I believe its in the top secret files on the top of the forum...