Motorcycle Repair: 1970 Honda SL 100 - Valve Spring Compressor, valve spring compressor, ebay auctions

Question
Mr. Silver,

I am rebuilding a 1970 Honda SL-100 and am having difficulty locating a spring compressor so I can replace the valves.  Any suggestions?

Thank you for your time!

Sam

Answer
Sam, if you plan to do this on a regular basis, buy one like this: http://www.sportingforless.com/product_info.php?products_id=37

You can use the deep socket technique shown here:
http://www.dansmc.com/valve.htm  but you will still need a compressor to reassemble it all again.

Most auto/motorcycle machine shops can pop the springs off in a few seconds, or ask the service department of your local m/c shop for some assistance.

Before you get deep into the overhaul, check the camshaft fit in the cylinder head. These early engines had poor bearing support and the cams get wobbly in the bearings, causing the point cam/advancer to be out of round when the cam is turning in the head. This causes a change in the point gap, which means variations in the ignition timing. This all leads to a poor running motorcycle engine.

Powroll in OR, has a needle bearing conversion for these engines, as I recall. The bearing surfaces in the head are bored out and a needle bearing goes into the head and another one is pressed over the camshaft bearing shoulder. This isn't cheap, but it is effective in curing the loose camshaft issues. Otherwise, you will have to buy a new cylinder head. I have seen some replacement head assys on Ebay auctions, but they are made in China, so not too sure how well they will hold up.

Bill Silver