Valve clearance/carbon deposit on plugs

If you haven't heard chirping noises or spitting back through the carbs, you might be OK. I agree with the kit idea. If it's only $50, then why not? Besides, if you adjust them, you might have to do it again in 500 miles. I'd check them at that point anyway.
Steve

Got it.. just ordered.

chconger wrote:

gcphoto wrote: so they don't come stock with all the same size shims? I would think they leave the factory with the same shims in each valve.

No, the shim is there to soak up the tolerances that get stacked together of the cast aluminum head, valve seats, and valves themselves. All these parts have a +/- specification when new. Taken together, they cannot meet the valve lash spec consistently.

The factory will put in shims in to make a spec that is impossible to meet otherwise due to these added tolerances of the various parts. Every valve will be different.

He is right, they wont be the same, but they should be close. You can tell quite a bit by the shim sizes that are installed. For example, if your shims are the upper range, say 2.50 to 2.70 that indicates little wear on the valves and seats, very thin shims (2.00 and below) can indicate the head has had a valve job in the past or is in dire need of one. If one valve has a much smaller shim than the rest that can indicate a problem too. Make a table and write down each shim you remove and corresponding clearance ( or lack of clearance) you have now. Reply with your measurements...

If you have a very thin shim already on a valve with no clearance then you can't fix the problem without a valve job, or replacing the head.

Thank you for that info Tyler. I found a handy valve clearance sheet at z1. www.z1enterprises.com/Documents/ShimSizesChart.pdf

I printed it out and will probably attempt this in the next few days. I know I probably needed to learn this eventually. I'm going to recheck my measurements again because it's been bothering me that I might have made a mistake.

Measure twice cut once.
Steve

I don't know if this has been addressed, but I always use a small suction cup to remove the buckets. You can pick up a set for like $1 at Walmart.

I had issues with 0 clearances with my 750 so I opted for the hot cams kit because I was lazy, and knew I would be adjusting them again the next season.

I remeasured.. there are no 0's as I first thought which is good, but it is still too tight and needs adjustment. It isn't as bad as I thought, meaning probably no burning. Shims and digital caliper are on the way. Should be fun!
1=.1
2=.06
3=.06
4=.08
5=.06
6=.04
7=.1
8=.06

Do you have a torque wrench that is calibrated in INCH pounds? You will need one. Ed

No eBay APP ID and/or Cert ID defined in Kunena configurationYes! It's on the way with the digital caliper. By the way, Ed.. is this the proper FSM?

No it is not, unless your 1978 SR is actually a KZ650-D1A instead of a KZ650-D1. The difference is that the D1 has 24mm VM24SS carbs and the D1A has 22mm VM22SS carbs. Check the intake side of the carbs. If the carb throats have an orifice at the 10:00 position they are VM22SS carbs (see 1st image below). If they do not have that orifice they are VM24SS carbs (see 2nd image below). This assumes they are the stock KZ650 carbs which can easily be identified by the ribs on the carb bodies.

If your bike has the VM24SS carbs and is a 1978 KZ650 SR it is a KZ650-D1. If that is the case, the manuals that include your year & model will have either part number 99924-1001-02 or part number 99924-1001-03 printed on the back of the cover and a photo of a red KZ650-B1 on the front cover. Those are the only 2 editions of the manuals that include the KZ650-D1. BE SURE TO VERIFY that the back cover has one of those 2 part numbers. Earlier part numbers of that manual, such as 99924-1001-01, will NOT have your model in them.

If you discover your bike is actually a KZ650-D1A let us know and I'll see if I can find the part numbers for the correct manual for that model. Ed

No eBay APP ID and/or Cert ID defined in Kunena configurationThe owners manual that came with the bike definitely says d1. So this must be the correct manual... Except it's from New Zealand and $68 with shipping.

I did the dreaded valve adjustment today. It was like open heart surgery with all the rags covering everything while trying to keep the wind from blowing tree debris into the crankcase. I took her for a test ride and noticed a big improvement on the top end and overall smoothness of the acceleration. I ended up with all the clearances between .08-.13. So that's not bad considering how tight they were before.

So, in the past couple weeks I've cleaned the carbs, did the valve adjustment, installed new coils, plugs and wires and an oil change. At the beginning of this thread I mentioned I had heavy black carbon on the spark plugs. I will check the plugs weekly to see if they stay clean. If they get blackened again I'll check back in to see what I can do about that.

Thanks so much for all of your help guys. It's so appreciated. I definitely couldn't have done it without this board. Here's a shot of the bike as she looks now after all the hard work to get her going.