Saving Old Seagulls

hi all
well i got some lapping paste and now the piston will fall by its own weight. the next step is getting the piston into the cylinder. i don't have a ring compressor so how do you guys get the piston into the cylinder ?

any and all suggestions are greatly appreciated

thanks
dalliance

A suggestion I saw recently on the AOMCI forum was to use a length of plastic cut from a clear soda bottle. Wrap it around the piston and pinch it tight to compress the rings while sliding the piston into the cylinder.

A 1" [25mm] wide strip from a food can works well also. Make piston circumference plus about 25 mm, then bend tabs about 20mm long at each end of strip leaving the circumference touching the piston about 15mm short of total piston circumference. Don't forget to have the ring end gaps over the pins in the ring grooves, start the piston in, grasp the tabs with pliers enough to compress the rings, tap or push the piston down. Some people just compress the rings with their fingers.

as Phil said I just make sure the ring gaps are over the pins and compress them with my fingers, it is an easy job

Before you insert the piston can you check that you have it the right way up & that the stopped end of the wrist pin is at the top.

hi all
i'm finally ready in install the piston into the cylinder. i'm going to use the original rings if i can. one of the rings is sprung out a bit, but compresses into the grove of the piston. i'm including a picture of the piston. is this ring ok to use or does it have to be replaced ?

thanks again for all your help and advise

dalliance

Does the non loose piston ring move? Is it free in its groove? Have you carefully removed both rings and cleaned the piston ring grooves so they are spotless?

phil
thanks for the reply. i hadn't taken the top ring off and it didn't move freely. so i attempted to remove the top ring. my greatest fear was realized when the ring broke. so now i answered my own question and am ordering a new set of rings.

thanks again for your assistance

dalliance

Sorry the ring broke, but both rings have to be loose and the ring grooves have to be clean, or its a waste of time. Stuck rings are a leading cause of low compression in old motors especially ones with oil rich mix ratios, even more so if the previous user decided to use non-TCW3 oil in the motor and ran it at low revs.

phil wrote: more so if the previous user decided to use non-TCW3 oil in the motor and ran it at low revs.

Didn't know TCW3 was around in 1965, so I think most had never seen synthetic oil.

P.S. TCW3 was Introduced in April 1992

True, the point I was trying to make apparently unsuccessfully, was that some people still use "old fashioned oil" [ SAE 30 lawnmower oil] in their motors, idle them and suffer the consequences. At a time [now] when TCW3 IS available.

I think you would be surprised just how many people don't use TCW3 and use a cheaper alternative or what ever is available.

hi all

well i got the new rings yesterday. i installed them with my fingers. i used some really light weight oil in the cylinder when i installed the rings. my next question is how do i seat the rings if they need seating and how much pressure should it take to move it in the cylinder ?

once again
thanks for all your help and advice

dalliance

Somebody suggested to me to drip feed brasso into the fuel system but that was for 4 strokes.

dalliance wrote: how do i seat the rings

Just put it back together and when ready, mix up a batch of fuel using non-synthetic oil and run it fairly hard, varying the throttle settings. The rings will seat themselves within a tankful or two.