Using Seafoam or the like to clean out stuck rings.

BikerMike

Active member
I just aquired a 1948 Cub and it smokes a little. I was going to run some Seafoam through it and change oil to see if this will clear it up a might. It runs great otherwise. Starts easily with the crank handle. Just trying to save myself a ring job.
 
Hi,
They say on here if the engine is smoking, to put Seafoam oil additive in the engine oil.
They sell it at auto parts stores.
Piston rings commonly get stuck, and then the engine will smoke.
It could help the compression, if the rings are stuck, and the Seafoam loosens them.

Make the engine work doing something when using the additive, so it warms up.
I have read on here of people having good results after using the oil additive.

The 1949 Cub operator's manual says to change the oil every 120 hours of use.
If the piston rings are wornout, the seafoam won't help much.
I would change the oil before putting the seafoam in, if you haven't changed the oil since you have owned the Cub, since the Seafoam is supposed to stay in it for some hours of use.
Remember to drain the oil filter chamber by removing the cap on the pipe under it. If it hasn't been drained there lately, the pipe could be plugged.

I have used Rislone, and had good results with that brand, it is an oil additive also.
I haven't used the Seafoam, but have read people's posts about it on here. :)
 
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Try the seafoam. Run it for a few weeks as much and hard as you can. I would also consider replacing the oil with 15-40 weight after the Seafoam treatment. I had a 49 that smoked some but had good compression. I was using 10-30 oil. I started using 15-40 and it reduced it a great deal. Later I also used ATF/ Acetone mix in through the spare plug holes and let it sit, occasionally rotating the engine by hand and redoing. That did stop more of the oil burn. Make sure you change the oil after the AFT/Acetone treatment before your start it.
 
Pouring seafoam right in the cylinders is great. Turn crank so pistons are all half way down. Carefully squirt in a 1/4 cup on each. Gently rock crank back and forth everyday for a week. Top up if it runs by rings. Change oil after. I use 15-40 rotella t4.
 
I run seafoam in mine all the time. I haven't ran it in the oil yet though. Mine only smokes at start up a little then quits when it's warmed up.
 
I run seafoam in mine all the time. I haven't ran it in the oil yet though. Mine only smokes at start up a little then quits when it's warmed up.
Mine smokes at startup, and when it is pulling hard going up a hill. We'll see if I can clear it up a bit. Thanks.
 
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