Topic: Installing 836 pistons

[martin_uk]

I am at the point of fitting the cylinders (jugs) to my no3 CB750.

I have the 65mm pistons from Cruisin Image and am finding the pistons/rings are difficult to insert.

I believe part of the problem is with the overbore as I have lost the lead in at bottom of bore.

My 60-65mm clamps were too small and 65-70mm a bit too big as slip off rings before inserted.

Doing on my own and may be better with 2 to control clamps.

May try a cut down beer can to reduce larger clamp.

Interested to know if others have found same issue and found a solution?

[teebee67]

Had the same problem - ended up cutting a very slight chamfer to the bottom of the liners with a rotary burr (could easily do it with a file). Only a very slight chamfer and, hey presto, they went in easily (this was after several hours trying to fit them myself and an hour or so trying to fit them with a mechanic friend.

[martin_uk]

Had the same problem - ended up cutting a very slight chamfer to the bottom of the liners with a rotary burr (could easily do it with a file). Only a very slight chamfer and, hey presto, they went in easily (this was after several hours trying to fit them myself and an hour or so trying to fit them with a mechanic friend.

Thanks its good to know I am not alone 

[voxonda]

Do you use two U-shaped piston supports Martin? I do it alone all the time. Just take your time.

[PeWe]

Had the same problem - ended up cutting a very slight chamfer to the bottom of the liners with a rotary burr (could easily do it with a file). Only a very slight chamfer and, hey presto, they went in easily (this was after several hours trying to fit them myself and an hour or so trying to fit them with a mechanic friend.

Thanks its good to know I am not alone 

So my liners are improved by my tuner that bored my cyl block to 65mm? No problem to get the pistons in with rings, no tools except fingers.
I did things in wrong order, honed bores then cleaned the head. Corroded bores within a few minutes   Dried them and oil did not remove the stains.

[Big Jay]

Not a problem when the shop is ised to doing big bores and they put the chamfer back in the bottom of the sleeve.

[HondaMan]

I am at the point of fitting the cylinders (jugs) to my no3 CB750.

I have the 65mm pistons from Cruisin Image and am finding the pistons/rings are difficult to insert.

I believe part of the problem is with the overbore as I have lost the lead in at bottom of bore.

My 60-65mm clamps were too small and 65-70mm a bit too big as slip off rings before inserted.

Doing on my own and may be better with 2 to control clamps.

May try a cut down beer can to reduce larger clamp.

Interested to know if others have found same issue and found a solution?

Without the taper at the bottom, it will be VERY difficult to install the oil rings without breaking them. The machine shop should have known that? I have mine always apply the taper again.

[MRieck]

Not a problem when the shop is ised to doing big bores and they put the chamfer back in the bottom of the sleeve.

Easy $hit.

[martin_uk]

I used a chamfer tool to create lead in, plus used longer screws from bigger clamps with smaller clamps to get a good fit.

Was able to fit OK and I thought great, then noticed I had forgotten to fit the 2 knock pins (dowels) Dohhhhhh

It would be easy to fix without removing cylinders if the studs were not so tight, so looks like I will have to start over.

[HondaMan]

I used a chamfer tool to create lead in, plus used longer screws from bigger clamps with smaller clamps to get a good fit.

Was able to fit OK and I thought great, then noticed I had forgotten to fit the 2 knock pins (dowels) Dohhhhhh

It would be easy to fix without removing cylinders if the studs were not so tight, so looks like I will have to start over.

Ow!
I wish I could say that I haven't done that myself, but you'll notice the silence on the next line:
...........................................
At least you're practiced at it now?

[PeWe]

If the studs are the old OEM they can be tight.
I could remove all of my old studs with double nuts only. I found it was easier to do a quick short jerk, tighten even more then loosen them. I removed all my later HD studs whithout lifting the cylinder block, head only. I tried with head on but the 4 shorter studs were too trícky.
They had not be sitting for long and had to be replaced due to excessive torque over the spec. and I was worried that they should snap when driving.

[Ravie]

I used my hone. Nice and uniform all the way around. I just moved it ever so slightly on that top ridge to round it a bit and they slid in like butta.

[martin_uk]

Second time was easier, but still a fiddle.

2015_0522after0005 by nitram2010, on Flickr

2015_0522after0011 by nitram2010, on Flickr