Today I decided to take my new motor and take the head off and slid the cylinder off the studs because i was curious. Went to go put it back on and had trouble getting the piston rings to sit so i could slide the cylinder back on. Is there an easy way or trick to slide it back on with no problems? I tried using needle nose pliers to press the piston ring to slowly push the cylinder on but ended up breaking the rings. I have another motor to take the rings out, but wanted to know any tips or tricks to seat it properly.
Piston rings in the way of sliding the jug on
- Thread starter dumpstercrusher
- Start date
Did you locate the ends of the rings around the pins in the ring grooves?
The pins are on both sides of the intake port and are there to stop
the ring ends from lining up and rotating into the port opening.
Simply squeezing the rings with your fingers works to install them.
Lots of posts here about this one.....
The pins are on both sides of the intake port and are there to stop
the ring ends from lining up and rotating into the port opening.
Simply squeezing the rings with your fingers works to install them.
Lots of posts here about this one.....
On every piston, there is a pin in the ring's groove that keeps the ring from moving around in its groove when its compressed. In the following picture, you can see what im talking about.
If the piston rings' gaps are not lined up with these pins, then the rings will bulge out and will not be able to fit in the cylinder. Many people try forcing the cylinder on, which breaks the rings. Look closely at the piston and find the pins, then line up ring gaps with these pins and compress the top ring, then slide the cylinder over it. After its over the top ring, compress the bottom one, and do the same. It helps to add a few drops of 2 stroke oil while doing this to make it all slide easier.
Hope I helped,
-Christopher
Edit: Ah, MBR beat me to it
If the piston rings' gaps are not lined up with these pins, then the rings will bulge out and will not be able to fit in the cylinder. Many people try forcing the cylinder on, which breaks the rings. Look closely at the piston and find the pins, then line up ring gaps with these pins and compress the top ring, then slide the cylinder over it. After its over the top ring, compress the bottom one, and do the same. It helps to add a few drops of 2 stroke oil while doing this to make it all slide easier.
Hope I helped,
-Christopher
Edit: Ah, MBR beat me to it
First align the ring end gap with the pin in each groove, the pin keeps the rings staggered. Put a light coat of oil on the piston and rings then lay two small wood rod under the piston to keep it from moving down then squeeze the top ring with your fingers while lowering the cylinder. Then do the same with the other, once both rings are in the cylinder remove the wood blocks and slowly slide the cylinder down.
Be sure the ring gaps are aligned over the locating pins in the ring grooves, then simply CAREFULLY use your fingers to squeeze each ring until it slips into the cylinder. It is pretty easy once everything is properly lined up. If the rings are not correctly lined up with the end gaps over the pins, you will damage the ring before ever getting it assembled.
You can also buy a piston ring compressor if you choose, but it is really not needed for a small two-ring single like the ht's.
You can also buy a piston ring compressor if you choose, but it is really not needed for a small two-ring single like the ht's.
Another tip: I have experienced difficulty with replacing a jug after opening a broken-in motor. I use a castor-oil mix, and it seems to leave more carbon-deposits than normal. Seems that when the rings are fully seated after break-in, there develops a very restrictive and form-fitting carborn residue on the rings' interrior radius AND the piston's grooves which can be enough to make replacement of the jug close to impossible since the rings won't properly re-seat in the gooves even when the pins are lined up. I use a razor-blade to scrape any buildup off the rings, and a small file point to remove any junk in the grooves before jug-replacement.
