Kevin's 1980 XS650-G "Restoration" Thread

[Jim]

Btw.... wanna easy way to de-carbon the combustion chambers?
Wire wheels. Get various sizes.
Took about 30sec to de-carbon this combustion chamber.

 

[Kevin Kruse]

Ok cool..

 

[Kevin Kruse]

Any tips for cleaning the pistons without destroying them with a screwdriver?

 

[grouchie77]

Use a broken ring to clean the ring grooves.

 

[Jim]

Paint stripper... acetone... lacquer thinner...

Usually you'll have your best luck with a stripper. Apply it, wait a bit and use a wire brush (handheld, not a rotary). Apply again and wire brush again. Repeat as required.

 

[grouchie77]

And a wire wheel. Chuck a little 2 incher up in a benchtop drill press and Bob's your sister.

 

[grouchie77]

I should edit that by saying I used the wire wheel in the drill press method for the crowns only. I hand wire brushed the outside diameters in my parts cleaning tank since those are machined surfaces.

 

[5twins]

Several applications of paint stripper will do the trick. I also use it on the combustion chambers and exhaust ports, and to remove the old gaskets. Here's some pistons after the 1st application ......

...... than after the 2nd ......

I then finish the clean-up with chrome polish and the little wire wheels in a Dremel ......

 

[Miker Vee]

Any tips for cleaning the pistons without destroying them with a screwdriver?

Oven cleaner

 

[Kevin Kruse]

Still working on cleaning stuff up while waiting for parts..

One thing I’ve done is deburr the groove in the head gasket mating area, I really didn’t like how ugly it looked, also did the outer edge and inside cam chain journal edge. Has anyone else addressed this? Or is it just my OCD?


Weight reduction? +5HP?? Or head gasket leaks..

 

[Kevin Kruse]

And inspecting my valves I notice some decent pitting at the ends of my intake valves, exhaust have no pitting and look good. Lash adjustment screws have a little wear also.



Can the valve ends be serviced by grinded down to a clean face or is that too much? I have access to a nice tool grinder at work. And that adjustment screw is the worst one, the others show less wear. Should I consider replacing ?

 

[Jim]

Most valves and adjusters have a very thin surface hardening. It wouldn't take much to grind it off. I don't think I'd risk it.

 

[Its been a long time]

Most valves and adjusters have a very thin surface hardening. It wouldn't take much to grind it off. I don't think I'd risk it.

^^^^^ This.

 

[Kevin Kruse]

New valves it is..

I’m looking at 2 NOS valves for $70 on eBay, or should I just get some new ones from 650 Central?

Here’s some pictures of the rest of the valves for reference..



Also question about new valves, will I be okay just lapping them into the original seats or do the seats need to be recut?

 

[Jim]

I’m looking at 2 NOS valves for $70 on eBay, or should I just get some new ones from 650 Central?

2 NEW intakes from 650 central are $70.... same price. Get the new ones if you can.

No need to recut seats unless they're damaged or you replace the guides.

 

[Kevin Kruse]

I wish I inspected these earlier, I just ordered a cam chain from him yesterday, shipping $ x2..

Would it be worth grabbing new lash adjustment screws?

 

[Jim]

I wish I inspected these earlier, I just ordered a cam chain from him yesterday, shipping $ x2..

Would it be worth grabbing new lash adjustment screws?

Yes.

 

[Jim]

Might want to look into elephants foot adjusters. I've no experience with 'em but @5twins has.

 

[Jim]

It's only money, Kevin...

 

[5twins]

Yes, the elephant foot adjuster screws, I was going to mention them to you. I put them in all my rebuilds. They address the issue of the worn stock adjuster screw and stop further wear on the valve stem tops. They require a bit of grinding on the rocker for assembly/disassembly clearance so can only be installed when the topend is apart. I used to grind off the whole bottom of the rocker but now I just bevel the screw hole with a tapered stone in a die grinder .....

You need to grind enough off so the beveled portion of the "foot" will retract into the rocker. This is required for assembly/disassembly, so the screws can be backed off enough so that they're not touching any of the rockers ......

The "foot" covers the entire top of the valve stem so wear from that one little point on the original screw is eliminated. Also, the "cup" where the "foot" attaches to the screw fills with oil in use and this acts sort of like a hydraulic adjuster. They run quieter and can be run with larger clearances as well (to a point - get too big and they'll make noise too).

The way I used to do it required removing the rocker arms. This new way doesn't, they can be ground in place.