Where's the fuel on the top cylinder? 1984 70hp

[cmuman]

Re: Where's the fuel on the top cylinder? 1984 70hp

hmmm. I'll check out that idle jet tonight. I think that might be it. I cant wait to get this boat out and run. (when the ice is gone that is) I have the 70hp engine on a 1976 saf-t-mate captain 15'6'' trihull. The last tri hull that I had had a 35 evinrude on it. This 70 should blow it out of the water. I cant wait. Darn winter.:-(

 

[tashasdaddy]

Re: Where's the fuel on the top cylinder? 1984 70hp

27 is idle jet, 29 is high speed jet, 22 could be a midrange jet. but not sure.

 

[cmuman]

Re: Where's the fuel on the top cylinder? 1984 70hp

I find it interesting that they hide jets behind other screws. I found 2 jets and I thought I was good.

 

[tashasdaddy]

Re: Where's the fuel on the top cylinder? 1984 70hp

it seals them so when the air comes thru the throat it creates a vacuum to pull the fuel into the carb. like a fertilize sprayer on a garden hose.

 

[cmuman]

Re: Where's the fuel on the top cylinder? 1984 70hp

I see. I'm enjoying working on these boat carbs. They ARE way simpler than automobile carbs. I just have to remember to find everything.

 

[cmuman]

Re: Where's the fuel on the top cylinder? 1984 70hp

I got it. I found the idle jet under a layer of yuck. I couldn't see any light through the jet at all. I used some stranded wire, carb cleaner, and compressed air to clean out the bottom of the bowl. I then pulled the drain from the other 2 carbs and did a quick clean with a wire just to make sure they were clear. Thanks for the help.

I do have a couple more questions.
I have to wait for Michigan to let me use my boat. Should I drain the carb until I use it again, or should I just leave it?

I was also wondering if anyone knew the cc or liters of this motor. I know boat motors are rated by hp. I was just interested.

 

[tashasdaddy]

Re: Where's the fuel on the top cylinder? 1984 70hp

prefer using seafoam in my fuel rather than draining. .

 

[cmuman]

Re: Where's the fuel on the top cylinder? 1984 70hp

are you talking about the sea foam additive or the spray? I've seen both around me.

 

[tashasdaddy]

Re: Where's the fuel on the top cylinder? 1984 70hp

seafoam additive in the can. add it to your fuel, per directions on the can. actually the stuff in the spray is the same stuff. but use for a different application. seafoam helps keep clean carbs clean. but does not clean dirty carbs. it is also use to decarbon the motor.

this is my decarb process.

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck

 

[guy74]

Re: Where's the fuel on the top cylinder? 1984 70hp

I was also wondering if anyone knew the cc or liters of this motor. I know boat motors are rated by hp. I was just interested.

49.6 cubic inches displacement on the three cylinder 70hp Johnny-rudes built in 1984.
Glad to hear you got it figured out.

 

[Willyclay]

Re: Where's the fuel on the top cylinder? 1984 70hp

Congratulations! Let us know what happens when you put it in the water.