TOPIC:

The valve with too much clearance is bent.

You sanded the valve shims? I dint believe that to be good practice, they are case hardened and could be ground out of true causing the engine to spit one out

floivanus wrote: The valve with too much clearance is bent.

You sanded the valve shims? I dint believe that to be good practice, they are case hardened and could be ground out of true causing the engine to spit one out

I slowly sanded 2 of them down by something like 0.2-0.3 mm by hand on a flat metal plate while constantly measuring them from all angles using a digital caliper to make sure they were perfectly flat. When finished they were as accurate as the machined shims. It was that or wait a week for new shims to be shipped because I called every shop in San Diego and couldn't find the size I needed. The rebuild was taking far too long because the machine shop had to do the valves twice due to major valve leaks the first time. I have a much better shop to use next time.

They were extremely hard so it took about 30 minutes per shim and I got blisters so I wouldn't recommend it unless desperate.

floivanus wrote: ...You sanded the valve shims? I dint believe that to be good practice, they are case hardened and could be ground out of true causing the engine to spit one out

+1
The FSM specifically cautions against grinding a valve shim, saying it may cause the shim to fracture.

My understanding is that the shims are case-hardened, and that regardless of perfect grinding, the original hardened surface is weakened or completed removed.

Good Fortune!

Patton wrote:

floivanus wrote: ...You sanded the valve shims? I dint believe that to be good practice, they are case hardened and could be ground out of true causing the engine to spit one out

+1
The FSM specifically cautions against grinding a valve shim, saying it may cause the shim to fracture.

My understanding is that the shims are case-hardened, and that regardless of perfect grinding, the original hardened surface is weakened or completed removed.

Good Fortune!

+2
No way I would do that, Sorry!
They aren't that expensive, I am sure if you knew what size you needed a member on here could help ya out!!. Or, Z1 Enterprises sells them individually.
Good Luck!
Ed

blakeem wrote:

floivanus wrote: The valve with too much clearance is bent.

You sanded the valve shims? I dint believe that to be good practice, they are case hardened and could be ground out of true causing the engine to spit one out

I slowly sanded 2 of them down by something like 0.2-0.3 mm by hand on a flat metal plate while constantly measuring them from all angles using a digital caliper to make sure they were perfectly flat. When finished they were as accurate as the machined shims. It was that or wait a week for new shims to be shipped because I called every shop in San Diego and couldn't find the size I needed. The rebuild was taking far too long because the machine shop had to do the valves twice due to major valve leaks the first time. I have a much better shop to use next time.

They were extremely hard so it took about 30 minutes per shim and I got blisters so I wouldn't recommend it unless desperate.

That's what happened. You can order 29mm shims from jetsrus on line. 3 day turn around time. My last order was delayed by Pay Pal so from now on, if I don't get a e-mail telling me it's shipped by the next day, I send Mike a e-mail and he takes care of it.
You might have to have the new shop tip the valves due to the old one taking out too much.
I have a saying, I didn't fall through the cracks, I was shoved!
Steve

He's gonna have to have new valves done; basically already indicated that he has at least one bent valve.
Kind of strange that one of the shims shattered. Too wide of clearance on that cylinder? Seems like it would take a good impact to shatter one of the shims.

We talked. He told me of a lot of Heli coils in the head and old shims. I told him it was a service bike and the shop "yard" re uses the shims for years. He might buy another head. The problem with that is having to go through it as well. The trans. sounds like it's worn out too. I got one for mine for about $60, back cut it myself and no more popping out of 2nd gear. This one had 30k miles. My old one had 87+k. Popping out of gear on hard acceleration can nick valves an destroy a engine. That's the most used passing gear. It's so frustrating having to sit behind some cage dummy waiting to pass like a old Honda 350 wile knowing I had the power to leave him in my fumes but can't.
Warning; don't buy a set without bearing caps. I've seen them for sale but them being missing suggests the bearings are damaged and or worn out.
Steve

i've seen this before in engines that I've repaired..... ..........some one ground the valve shims, result, fracturing/breakage after grinding the shim.....bad idea results in more engine damage ....

Back in the 70's when I bent valves due to a broken chain, I had a problem. No shims, no shop for 60 miles, tight valves. I took a beer can, cut some shims out of it and put them under the bearings. I punched a hole it them for the oil passages and shimmed under the cam towers. It worked. I got my shims, put them in on site and thanked god I didn't spit out the other shims while going there.
Desperation leads to desperate measures.
Steve

turboking wrote: i've seen this before in engines that I've repaired..... ..........some one ground the valve shims, result, fracturing/breakage after grinding the shim.....bad idea results in more engine damage ....

The shims that I sanded down did not break, it was one of the original shims with a machined finished on both sides that shattered. I sanded the shims by .015 mm (very little) on both sides to leave as much hardened surface as possible and finished wet sanding with 1000+ grit sand paper until they had a uniform mirror finish. They didn't leave any scoring on the cam shaft lobes and were equal thickness all the way around.

What I learned from this is that I should just replace all the shims with brand new ones because they can get brittle over time.

If you want brand new shims and you're getting your shims from a dealer, make sure you ask for new ones. alot of the time they will sell you used ones. the oldschool shops will let you swap shims.

Yeah Sams will for $5. I used to have an assortment until my son left them out in the rain. He liked to sabotage things. He resents everyone. My daughter is just the opposite. Go figure.