CB650C Project from P. I. Needs help of a brethren..

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usbear
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby usbear » Thu Aug 22, 2013 7:25 pm

Well The Rocker shaft spacers finally showed up. They are 1mm,1/2mm and 1/4 mm.
.040,.020 and .010.
The 500 we did in the shop took .030.

1) measure the side play in your rockers by moving side to side against the spring and see what your clearance is, and I will send you enough to do yours, about .50 each.
2) bottom end engine was in the fed ex truck today for delivery but did not make it by 3:30 pm when I was at my post office but I am sure it was delivered and will see it tomorrow.
3)I did not order cam chains yet.


You can measure side play with a feeler gauge between the end of the shaft and the head.

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Bongskit
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby Bongskit » Fri Aug 23, 2013 9:12 am

bob sent you an email.

so I cleaned up a little and removed the valves. tomorrow i will snap more photos and show you guys the things that bothers me.

valve spring contraption made out of aluminum 19mm bmx bottom bracket spacer cut to length and modified. 6" C-Clamp and bonded a circular rubber on the axle screw head.

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cylinder block mating surface cleaned, base and head.

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the valves

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now my dilemma:

Had a little resistance pulling in/out intake valve #1. Exhaust valve #2 took more efforts to pull out.I had to twist it to get it out. I've tried putting both of them in other seats and symptoms follows. Intake valve doesn't feel so dramatic but the exhaust one is really bothering. I didn't force it all the way to get in other seat and did not try to put it back on its original seat. You think I have a bent valve? Also, the valve guide on exhaust #2 has a spiral thread like that of a barrel of a gun maybe due the method that I did pulling it out.

what do you guys think? photos to follow

cb650
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby cb650 » Fri Aug 23, 2013 7:07 pm

replace the valve at the least.
Did you clean the tank out?!?!?!?!

jagans
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby jagans » Fri Aug 23, 2013 7:19 pm

Hi Guys,

Great pictures of the clear tube method. Its nice to see someone actually knows about the Macro feature and how to adjust the flash output. Only one thing to add, shoot at a slight angle to avoid flash back into the lens (Valve cover gaskets)

Now, can you tell me which tube, from left to right is showing the correct float height, since we have no idea which tube is No. 1 ? I assume the left, but maybe you count from the right over there. LOL

By the way the mechanical carbs on the 79, and 80 PD50A have adjustable floats. The 81 and 82 have CV carbs and plastic floats which are not adjustable, and the spacing is different. Different heads.

jagans
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby jagans » Fri Aug 23, 2013 7:31 pm

Can you show a couple of top photos of the head where the cam sits? I took my head off several years ago (My engine that is) and noticed something in the casting that I think was causing a lack of lubrication to one of the journals. I posted this several years ago, but I forget what it actually was that was bothering me (Dont laugh, Nam, the 60's, 67 years old and trying to keep Budweiser's stock up took their toll)

Maybe if I see it again............ I think it had something to do with a lubrication well that could not drain back to the sump. I fixed it with a Dremel and an abrasive wheel. I think that's why these heads developed leaks.

MiGhost
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby MiGhost » Fri Aug 23, 2013 7:39 pm

In the pic on the valves the top left (I), and second from top right (E) valves look visably bent in the pic. You can double check them by rolling the stems on a flat plate, and watch for any wobble in the head. Also look for any visable light showing under the stems as you are rolling them.

If these are the two in question. Then replacement is deffinately in order.

Ghost
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

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Bongskit
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby Bongskit » Sat Aug 24, 2013 8:18 am

jagans wrote:Hi Guys,

Now, can you tell me which tube, from left to right is showing the correct float height, since we have no idea which tube is No. 1 ? I assume the left, but maybe you count from the right over there. LOL
.


we may have been conquered by japanese before but we are more "westernized" :lol:

its left to right. the solo pic is the correct height afaik.

Can you show a couple of top photos of the head where the cam sits? I took my head off several years ago (My engine that is) and noticed something in the casting that I think was causing a lack of lubrication to one of the journals. I posted this several years ago, but I forget what it actually was that was bothering me (Dont laugh, Nam, the 60's, 67 years old and trying to keep Budweiser's stock up took their toll)


as you wish!

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MiGhost wrote:You can double check them by rolling the stems on a flat plate, and watch for any wobble in the head. Also look for any visable light showing under the stems as you are rolling them.


so I did and it looks like its not bent at all. i snap some photos as well.


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options?

so i run some inventory and compared it to the break down of parts list. looks like it is missing something and some are not supposed to be there

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now these looks like a cutoff from a valve seal used as a washer just right after the valve seal itself.

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tell me i am missing something...

usbear
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby usbear » Sat Aug 24, 2013 10:24 am

The P.O. stacked half of the old seal on the valve stem also?

This will cause a clearance problem for the the spring retainer and cause binding which will give you the marks you see on the valve stem.

The marks/burrs can be polished out by hand.

You can start by taking the sharp edges off with a fine stone or sharp fine grit sandpaper on a flat surface. 240 to 400 grit to start or just fresh emery cloth and polish like a shoe shine motion around the stem top.
Wrap the good stem base with tape if you want to avoid drifting into the undamaged stem area, and also as padding so you can hold valve in vise. Use soft material like wood,plastic or leather on the jaws to hold the valve stem firm while polishing the burrs off.
Also on each valve stem tip above the keeper groves you can sand ,polish remove any hammerred portion of the stem. In the future before removing the valve you can and should clean up the valve stem tips for these burrs and for enlarged stems due to being hammered by the tappets.
Also the keepers will sometimes hammer the stem and raise a ridge that needs to be removed.
Easy and quick to do with emery cloth and a hard fine stone. like one you use for knife sharpening.
I use a small triangle file to get them clean and then emery cloth.
when removed I polish on a buffing wheel I have set up for Gunsmith work.

Your machine shop will be able to do this rapidly with their equipment if you don't want to mess with it. Also the machine shop will inspect your valves when you bring them in for grinding, and advise of reuse.
Wear in the tip area is of no consequence, only the stem diameter where it enters the valve guide.


If you think about taking a shop hammer with a round end for Penning or expanding metal parts so they don't come out, much like a rivet then you think about the many million times the valve stem tips have been hit by tappets , you realize that it is common to expand or burr the tips of the valve stems. This should be addressed before removing the valves and can be done in less than 5 minutes for the entire set of valves.
Last edited by usbear on Sat Aug 24, 2013 2:03 pm, edited 1 time in total.

jagans
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby jagans » Sat Aug 24, 2013 1:23 pm

Thanks for the great photo, again. Maybe I am wrong, and one of you guys can enlighten me, but if you look at the photo right under "As you wish" you will note a drain hole for oil to return to the sump in the far right gallery. I do not see a similar drain hole in the second gallery from the left. Again, I could be wrong but it appears that this would allow oil to build up above the valves on that side and leak down into the cylinders there. It is my opinion that those oil holes are really small, and could gum up pretty easily. Frankly, I do not recall what I did, as it was a long time ago. but I drilled a hole somewhere to allow the oil back to the sump. If your head has a drain hole on the left side, you should be OK. If not, you may want to check it out.

Thanks to you all for the fuel level info
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jagans
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby jagans » Sat Aug 24, 2013 10:51 pm

This oil flow thing has been bugging me. I looked at the section through the engines pressure lubrication chart and I see that the oil galleries in question (Red Arrows, last post) are sumps into which the camshaft lobes dip lubricate. The oil that lubricates the cam journals under pressure flows into these galleries, and I cannot remember how it makes its way back to the sump from there. It looks like it would flow over the partitions onto the valves. Maybe one of you that has had the head apart more recently than me can fill us all in on the path the oil takes after entering the galleries. I do remember being flabbergasted at the fact that the cam rode right on the aluminum journals with no babbitts in place that could be replaced. Basically if your oil pressure drops, your mill is toast. At least your head is. Babbitts (Bearings) would have been nice, dont you think?

Thanks.

usbear
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby usbear » Sat Aug 24, 2013 11:40 pm

Return holes into the chain galley, and onto the chain the chain slings oil up also and the oil returns onto the upward and downward travel of the chain. All this oil interferes and whips it up a little. Hot pockets for sure.
Some riders and racers reroute this oil return by plugging return holes and drilling and mounting return tubes to the bottom end, or mounting an oil cooler in line for the return.

Holes are drilled all the way through from the side of the Head and the outside holes are plugged and can be seen from the outside of the head when looking at ether side.
The rest of the holes then drain back into the sump from the holes in the valve spring pockets.

These engines oil TOO Much on top end.
The pockets under cam lobes are for startup before oil gets pumped to top end.

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Bongskit
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby Bongskit » Sun Aug 25, 2013 5:12 am

jagans: i dont think its a drain hole, at least to mine, its just a scar. If it was a drain hole, its gonna be messy and oil will be all over the middle fins of the head. And even it was originally like that, I couldnt imagine how, with cruising speed and all the elements passing through in between the fins. I think the oils just drips down back through that middle channel.

And I agree how much oil in that pool and how important that rubber coin seals are.

MiGhost
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby MiGhost » Sun Aug 25, 2013 3:32 pm

While you have the head apart with the valves out. Could you get a pic of the valve spring area. I highly suspect that you will find the oil drain holes tucked into the corners.

Ghost
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

jagans
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby jagans » Sun Aug 25, 2013 8:46 pm

Thanks Guys. Yeah, there has to be return holes to the sump near and below the seat of the valve springs. The fact the journals are simply line bored in the aluminum head gives me the willies. There should have been Babbitt bearings, but I guess thats how they saved money on these. These pictures should prompt us all to change the oil and filter often and add some MMO for good measure. I'm gonna check the pressure at my pump tomorrow. :shock:

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Bongskit
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Re: CB650C Project from P. I. Needs help of a brethren..

Postby Bongskit » Sun Aug 25, 2013 11:48 pm

MiGhost wrote:While you have the head apart with the valves out. Could you get a pic of the valve spring area. I highly suspect that you will find the oil drain holes tucked into the corners.

Ghost


your official photographer. :lol: let me know if there's more pictures you would want so we can archive it for future reference.

all valve channels leads to cam chain pit

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now for the bad news :x I dont have a gorrila hand but I would like to think it is actually brittle already than the rest.

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here are the rings in each respective cylinder

1 - 1

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1 - 2

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1 - rail

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2 -1

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2 -2 BROKE!!!!!

2 - rail

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3 - 1

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3 - 2

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3 - rail

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4 - 1

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4 - 2

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4 - rail

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