Decarbing 63 starflite 75 right mix? shock tank?

[heryrg2711]

I'm looking to do a decarb of 63 starflite 75hp. What is the best mix of fuel/seafoam/marvel/stabalizer i need to run through in order to get the same effect of RingFree?
I'm getting low compression and i think all the rings are stuck. I have seafoam and marvel mystery. I was thinking of running a gallon of fuel with a can of seafoam? Is this too much?

Also, i read somewhere about running a shock tank of gas, which will clean all the buildup. Anybody know how to mix one of these tanks?
If i'm going to run a gallon of fuel with a lot of seafom, can i do this in a test tank or a load is needed?

 

[wilde1j]

Re: Decarbing 63 starflite 75 right mix? shock tank?

A gallon of gas to a whole can of SeaFoam, plus oil. Test tank or hose is fine, then run the crap out of the boat on the water after waiting an hour or two.

 

[heryrg2711]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Thanks, will run a gallon seafoam/gas today and maybe have chance to open water test it tomorrow.

 

[lindy46]

Re: Decarbing 63 starflite 75 right mix? shock tank?

I'd presoak the cylinders in Seafoam first. Tilt the motor up, remove the plugs, and pour a little Seafoam into each cylinder. Let sit overnight.

 

[wilde1j]

Re: Decarbing 63 starflite 75 right mix? shock tank?

If you get al lot of smoke, you may want to repeat the treatment. Smoke is confirmation carbon is being removed.

 

[heryrg2711]

Re: Decarbing 63 starflite 75 right mix? shock tank?

I poured a small amount into the cylinders about 3hrs prior but didn't raise the motor, was a bit lazy
I warmed up the motor and then switched to seafoam mix, i did 3 cycles of 15 min and off. First cycle it was good and smokey, after rest it was about the same amount of smoke not significantly more. Second cycle almost the same thing, maybe tiny amount less, Third cycle followed the same pattern.
It was still smokey after i ran the gallon. I also sprayed a bit of marvel mystery into the crabs while doing this and it smoked significantly more.

The compression was about the same, around 70, maybe higher by 1 or 2psi.
Should i just do this again?

 

[BonairII]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Probably wouldn't hurt to decarb again (if the smokiness never stopped). You looking to raise your compression by a bunch?

Probably not going to get 20psi more out of a decarb. Is compression pretty even on all cylinders? I would doubt that all rings could be stuck so that all cylinders could still be even.

 

[boobie]

Re: Decarbing 63 starflite 75 right mix? shock tank?

My dumb question would be, how good does this mtr idle??

 

[heryrg2711]

Re: Decarbing 63 starflite 75 right mix? shock tank?

The smokiness never stopped, i was hoping this would put me in the 80-90 range, Right now it is even all around at 70-72.
The motor idles well and runs decent in low speed, but has no power.

I think i'll decarb again. What do you guys think of using Marvel mystery oil instead of seafoam? Also can i run the motor for longer then 15 minutes before rest? Is it temperature or running seafoam for longer period of time that limits this? The cylinders feel "cool" to touch way into 3rd run.

 

[BonairII]

Re: Decarbing 63 starflite 75 right mix? shock tank?

If cyls are cool...maybe your vernaterm(thermostat) is stuck open. Use the Seafoam!

I would warm the motor up....pull plugs and HEAVILY spray Seafoam in the cylinders holes -rather than pouring it in(with motor tilted up). Let it sit overnite if at all possible. Then go thru the decarb process.

Idle the motor the next day until the smoke clears. Then run the heck out of it on the water.

When you're done, you're probably going to want/need to change your plugs.

 

[wilde1j]

Re: Decarbing 63 starflite 75 right mix? shock tank?

The run hard time after the wait period is when you should see smoke, if there's still carbon being blown out. It will always smoke during the application of SeaFoam.

 

[194269]

Re: Decarbing 63 starflite 75 right mix? shock tank?

I have spent a lot of time working on the old 60's v-4's and if you want to get the comp. back up to 90 -100, this is what you will have to do. Pull it apart and re-ring it. And most likly replace half or more of the piston because they WILL be scored. They used bad piston material and thick rings in those days, which where prone to sticking, causing blow by and scoring pistons. They where also designed to run on 24:1 fuel mix and when they switched to 50:1 they stuck a fork in them. I know I will get some flack on this, and please understand I am not picking on them. They are good outboards when used with respect. Use good oil and mix at 24:1, just my .03 worth.

 

[heryrg2711]

Re: Decarbing 63 starflite 75 right mix? shock tank?

So i ran it today. In the morning i sprayed some marvel oil into the cylinders ( didn't have seafoam) I let it stay for about 7-8hrs.
I then ran it with 1can seafom/1 gallon mix for about 30 minutes, 15min on/off. It was still smokey but not as much as last time.
There was a lot of sludge in the bucket, is it the carbon burning off? Look the pic below. There is also a water leak in the back of motor, on the bottom out of a strange box. I posted a video of this, could someone please check it out and tell me what that box is and if this leak is bad. I also posted a pic of it, little streak is a water drop.
EDIT: NO video sorry


I've been using 50:1 with Lucas semi synthetic oil. Do a lot of people use 24:1, because most places and people said 50:1.

 

[194269]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Here' what I think, (again just my .03 worth), your outboard's basic design was done in 1956 and 1957 and released for production in 1958 (know as the Fat Fifty). In 1960 it had a minor redesign when it became the starflite 75, it got a bigger bore (3.375 vs 3.00) and one addictional crankshaft seal ring. The engine was designed to run on a 24:1 oil mix, the 50:1 oil mix did not start showing up until the late 60's and your engine is going to be 49 years old. I would gather that 85 -90% of the people you ask today never heard engines running on any thing less then 50:1 mix. If you need a cut off date on OMC engines for which uses 24:1 and 50:1 mix I would use 1969 for all engines and the 1968 55HP three cylinder Triumph, which was designed with 50:1 oil mix in mind. Your water leak is most likely a cracked lower therm. housing, a new housing will be stronger in that area.

 

[heryrg2711]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Thanks, I'll experiment with the oil and see how goes it. Whats the sludge in the bucket? Carbon?

 

[lindy46]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Thanks, I'll experiment with the oil and see how goes it. Whats the sludge in the bucket? Carbon?

Mostly unburnt 2-cycle oil which has done it's job and been expelled in the exhaust.

 

[jimmbo]

Re: Decarbing 63 starflite 75 right mix? shock tank?

Here' what I think, (again just my .03 worth), your outboard's basic design was done in 1956 and 1957 and released for production in 1958 (know as the Fat Fifty). In 1960 it had a minor redesign when it became the starflite 75, it got a bigger bore (3.375 vs 3.00) and one addictional crankshaft seal ring. The engine was designed to run on a 24:1 oil mix, the 50:1 oil mix did not start showing up until the late 60's and your engine is going to be 49 years old. I would gather that 85 -90% of the people you ask today never heard engines running on any thing less then 50:1 mix. If you need a cut off date on OMC engines for which uses 24:1 and 50:1 mix I would use 1969 for all engines and the 1968 55HP three cylinder Triumph, which was designed with 50:1 oil mix in mind. Your water leak is most likely a cracked lower therm. housing, a new housing will be stronger in that area.

1964 was the year Evinrude/Johnson switched to 50:1