I recently bought a '66 Bonneville and the guy said he sprayed WD40 into the cylinders before he put it away for winter last year. Before I try to get it started, should I expect damage due to the WD40? I assume it would have washed the oil from the cylinder walls. Any ideas or experience on what I should expect? Should I be safe just putting fogging oil down the cylinders and kick it over a few times? Any insights are appreciated.
i personally wouldnt give it a 2nd thought. i would put about table spoon of fresh oil in with the plugs out and kick the thing over till i saw oil coming out the return line. this of course assumes it hasnt wet sumped over time. which it may have.
Agree on squirting some motor oil into the cylinders.
If it wuz me, I'd then rotate the motor slowly with the plugs out, just to wipe the oil onto the cylinder walls.
I'd also remove the valve inspection caps and squirt some oil on the valve stems, so maybe some will trickle down into the guides.
 Before starting, I'd want to establish my own baselines for the bike, so I'd drain the float bowls, set the valve clearances, check battery, and if it has points ignition, clean and gap the points and set the timing static, and install newspark plugs.
Then I'd make sure there's oil in the oil tank, the primary drive, and the gearbox. You can also take a clean squirt can and prime the oil lines with fresh motor oil. And then I'd fire 'er up.
After getting it warm, or hot after a test ride, I'd change all three oils.
Lots of threads on the forum about kicking it til oil returns, and I used to do it. The non-kickers won me over, for one thing, parts that rely on splash for lubrication will not be lubricated while yer kickin'. The last time I kicked one til oil returned, it took 100 kicks. That's a few hundred revolutions without lubrication for some parts.
Last edited by kurt fischer; 09/19/175:53 pm. Reason: "Before starting ... "
WD stands for Water Dispersant---so I guess WD 40 in the bore would stop water and therefore stop it rusting. Must admit it is not the first thing I would put in a bore before storage--but--better than nothing I guess.
WD-40 turns gummy after the solvents evaporates and if in the open will attract dirt. I suggest squirting fresh WD-40 in the cylinders to dissolve the WD-40 in there and turning over to free the rings. It also works as a starter fluid. For long storage I would use Marvel Mystery Oil or if unavailable, motor oil.