Topic: Pondering Piston Puzzle

[chippyfive50]

So far the consensus from the posts I've read for piston re-install is to mount the pistons on the rods first.
The more I look at it, it seems like it would be much easier to stick all of the pistons in the jug first, then
put the 2/3 pins in from inside out, then do 1/4, pins from outside in.
has anyone tried this, or am I missing something?
Thanks

[HondaMan]

So far the consensus from the posts I've read for piston re-install is to mount the pistons on the rods first.
The more I look at it, it seems like it would be much easier to stick all of the pistons in the jug first, then
put the 2/3 pins in from inside out, then do 1/4, pins from outside in.
has anyone tried this, or am I missing something?
Thanks

Yep, I have tried it.
I ended up with 2 circlips inside the crankcase and a screwdriver stuck in the wall, all the way across the shop, from the frustration. 

I recommend doing it the more common way, but be sure to FIRST take the time to grind/sand/hone the sharp edge of the bottom of the cylinders, especially if you just bored it. This edge can make it VERY difficult to get it together without snagging or damaging a ring or two, and is the most common point-of-failure in rebuilds (especially 811cc and larger bores).

[Big Jay]

So far the consensus from the posts I've read for piston re-install is to mount the pistons on the rods first.
The more I look at it, it seems like it would be much easier to stick all of the pistons in the jug first, then
put the 2/3 pins in from inside out, then do 1/4, pins from outside in.
has anyone tried this, or am I missing something?
Thanks

I recommend doing it the more common way, but be sure to FIRST take the time to grind/sand/hone the sharp edge of the bottom of the cylinders, especially if you just bored it. This edge can make it VERY difficult to get it together without snagging or damaging a ring or two, and is the most common point-of-failure in rebuilds (especially 811cc and larger bores).

Or you could have your cylinders bored by someone that machines a nice chamfer back in the bottom so you can get the rings in easier 

Also, Popcycle sticks were invented for putting piston rings back up in the cylinder.

Jay

[MRieck]

So far the consensus from the posts I've read for piston re-install is to mount the pistons on the rods first.
The more I look at it, it seems like it would be much easier to stick all of the pistons in the jug first, then
put the 2/3 pins in from inside out, then do 1/4, pins from outside in.
has anyone tried this, or am I missing something?
Thanks

I recommend doing it the more common way, but be sure to FIRST take the time to grind/sand/hone the sharp edge of the bottom of the cylinders, especially if you just bored it. This edge can make it VERY difficult to get it together without snagging or damaging a ring or two, and is the most common point-of-failure in rebuilds (especially 811cc and larger bores).

Or you could have your cylinders bored by someone that machines a nice chamfer back in the bottom so you can get the rings in easier 

Also, Popcycle sticks were invented for putting piston rings back up in the cylinder.

Jay

Yeah....the chamfer is nice. It can also leave a knife sharp edge so be careful. If you put supports under the 2 pistons to stabilize them it is a million times easier. Trying to get the process started with rocking pistons is frustrating.

[MRieck]

So far the consensus from the posts I've read for piston re-install is to mount the pistons on the rods first.
The more I look at it, it seems like it would be much easier to stick all of the pistons in the jug first, then
put the 2/3 pins in from inside out, then do 1/4, pins from outside in.
has anyone tried this, or am I missing something?
Thanks

Yep, I have tried it.
I ended up with 2 circlips inside the crankcase and a screwdriver stuck in the wall, all the way across the shop, from the frustration. 

I recommend doing it the more common way, but be sure to FIRST take the time to grind/sand/hone the sharp edge of the bottom of the cylinders, especially if you just bored it. This edge can make it VERY difficult to get it together without snagging or damaging a ring or two, and is the most common point-of-failure in rebuilds (especially 811cc and larger bores).

Only 1 screwdriver ended up in the wall Mark. Boy....great self control sir.

[City Boy]

Hi.Over the years,I have always used the Honda piston supports and lowered the cylinder onto the pistons in the normal manner.Very frustrating and rising blood pressure,especially with litlle to no chamfer on occasion.My last build,a 900F,went at it different.Installed pistons one by one into cylinder,mounted cyl. to upper crankcase,held in place with copper water pipe and nuts on studs,then inverted and bolted rods to crank.Bye bye old way.   Rock On

[754]

Does this work well with the cases together...











..............running...................

[HondaMan]

Does this work well with the cases together...











..............running...................

In the frame? 

[754]

+ 1 on the popsicle stix

its hard not to laugh when some used a steel screwdriver, and then breaks a ring... sometimes you can get them in with your fingers.. 1 pce rings.

I use a Hastings ring compressor at times, work well, back off screw to rlease the latch.. will look for model #.

Cant find a number for it, but it is the band type, but only about 1" or 1 1/8" high.

[City Boy]

Yes,of course my described method works with assembled cases,even better in the frame!!!   Rock On

[chippyfive50]

Thanks for all of the info fellas>>>
My bike has 11,000 miles on it, and still had visible factory hone marks in the jugs.
I did a very light "de-glazing hone" with my cordless drill. I am using the stock size honda rings
and found it not horribly difficult to get a piston into the bottom of the jug on my bench with just my
fingers. (This is what prompted this thread)
My cases are intact.
I have it apart to take care of some oil leaks, which has lead to the usual >> (you know;  powder the frame, repaint tank, new decals, tires, rework the clocks, ignition, new wiring harness.)
BTW, should I replace the cam chain guide and tensioner?? they look fine.
thanks

[HondaMan]

Thanks for all of the info fellas>>>
My bike has 11,000 miles on it, and still had visible factory hone marks in the jugs.
I did a very light "de-glazing hone" with my cordless drill. I am using the stock size honda rings
and found it not horribly difficult to get a piston into the bottom of the jug on my bench with just my
fingers. (This is what prompted this thread)
My cases are intact.
I have it apart to take care of some oil leaks, which has lead to the usual >> (you know;  powder the frame, repaint tank, new decals, tires, rework the clocks, ignition, new wiring harness.)
BTW, should I replace the cam chain guide and tensioner?? they look fine.
thanks

Ah, I see you got infected along the way...
The tensioner rollers and slippers often get hard, enough so that they start chunking out little pieces when the engine is revved high and there is a bit of slack in the cam chain. Check to see if yours feel like steel: if so, try finding some new ones. They should have a very hard rubber feel to them. Honda used metal ones in their racing versions of these engines, to hold the timing still a little better, but these can shorten chain life.

[jtb]

I have it apart to take care of some oil leaks, which has lead to the usual >> (you know;  powder the frame, repaint tank, new decals, tires, rework the clocks, ignition, new wiring harness.)
BTW, should I replace the cam chain guide and tensioner?? they look fine.
thanks

I just don't understand how this could happenj.