Installing the cylinders...

[brs127s]

Hey all,

My neighbor and I are going to try to put my 850 back together tomorrow night. My question, is it possible to intall the cylinders over the pistons without using a ring compresser? He thinks we may be able to compress the rings by hand and slide the cylinders down over the pistons. Also, do I push the 4 o-rings which go on the base of the cylinders into the groove at the base of the cylinders, or do I just push them so far and let the base gasket push them the rest of the way?

[Anonymous]

Push the o rings into the groove. Not sure if it really matters, though.

With 2 people its perfectly possible to slide barrels down using your fingers and maybe a small flat screwdriver to ease the rings into the cylinder. This assumes you have a good taper machined at the bottom of your bore. Take your time and be careful.

[daveo]

You may be able to do it by hand, but, it's easier to get 2 big hose clamps and use them, do center 2 first, it helps to block the crank from turning while you're doing them also. I would grease and seat the O-rings in their groove by hand first, to make sure they're not pinched

[Anonymous]

You may be able to do it by hand, but, it's easier to get 2 big hose clamps and use them, do center 2 first, it helps to block the crank from turning while you're doing them also. I would grease and seat the O-rings in their groove by hand first, to make sure they're not pinched

This method worked great for me. Be sure to oil everthing with motor oil.

Roman

[silverhorse47]

Some people also make ring compressors out of tin can and vice grips...you cut out a band of the tin can and bend up two tabs so that the nose of the vice grips can grip and close them together around the rings. Put a little duct tape over the cut edge if you like to keep things safe.
Then you can just pop off the vice grips once the rings are into the bores and hook the compressors up to the next two cylinders.
It doesn't take much pressure to hold the rings into the grooves and the tin works well.

S.

[Billy Ricks]

Big wide zip ties work well.

[Hap Call]

Brandon, did you check your piston ring gap at the top of the cylinder, midway down and at the bottom of the ring travel? This is critical with new rings.


Hap

[daveo]

Brandon, did you check your piston ring gap at the top of the cylinder, midway down and at the bottom of the ring travel? This is critical with new rings.


Hap

Good call Hap! actually you may want to match each compression ring to the cylinder bore it fits most closely

[skip]

You may be able to do it by hand, but, it's easier to get 2 big hose clamps and use them, do center 2 first, it helps to block the crank from turning while you're doing them also. I would grease and seat the O-rings in their groove by hand first, to make sure they're not pinched

This method worked great for me. Be sure to oil everthing with motor oil.

Roman

I have used the hose clamp method on two or three occasions It has always worked for me

[brs127s]

Hap,

We will do that tomorrow night. My buddy is bringing a ring grinder with him. Although I do have a question for you. Now that you mention the different areas for checking the ring gap, shouldn't it be the same since I had the cylinders honed? They were honed with an actual honing press, not the ball hone like I had originally planned to do. I went with the press hone upon the recommendation of the machine shop owner. He said that this way, I would know that my cylinders were true, whereas the ball hone would not true the cylinders. In fact, he was suprised when he honed the cylinders. He said those were some of the hardest sleeves he had ever honed. My buddy said if his boss hadn't already shot me a price, he would have charged me more.

Thanks to everyone else for all the suggestions also.

[Hap Call]

Hap,

We will do that tomorrow night. My buddy is bringing a ring grinder with him. Although I do have a question for you. Now that you mention the different areas for checking the ring gap, shouldn't it be the same since I had the cylinders honed? They were honed with an actual honing press, not the ball hone like I had originally planned to do. I went with the press hone upon the recommendation of the machine shop owner. He said that this way, I would know that my cylinders were true, whereas the ball hone would not true the cylinders. In fact, he was suprised when he honed the cylinders. He said those were some of the hardest sleeves he had ever honed. My buddy said if his boss hadn't already shot me a price, he would have charged me more.

Thanks to everyone else for all the suggestions also.

It is something I do everytime...it dosen't hurt to do it and you get to check that the honing was done properly. If it was done properly, you should see very little variance. Be careful grinding the ring ends...they can break easily and if you grind off too much it is hard to glue it back on! 8O Dave is right...if you can match the rings to the cyliner that is closest to the ring end gap diameter that is the best way to go.

It is cool following you through this rebuild! Keep us updated!

Hap

[focus frenzy]

I would like to add, be very careful with the rings when you put them on the pistons, the rings are made from a hard metal and don't bend very well before they break, also they tend to have very sharp edges and will cut you to the bone! (been there done that)

[Anonymous]

I used a screwdriver and slowly pushed each one in individually, slow, but works, a ring compressor would be good, I had problems with the hose clamp attempt... didn't slide off nicely

[brs127s]

Thanks again everyone. We intalled the pistons, cylinders, and head last night. Everything went on very well. We put the pistons/rings in the cylinders by hand. The No 2 and 3 pistons were not easy, but once I got the hang of it, 1 and 4 were pretty easy. All I have left to install is the cams, chain adjuster, and the carbs.

I will be back on the road in no time.