One afternoon I rode up this fairly steep duneside road down by the beach. Is about 3 blocks long up side of dune to the top.
At top can look back over the Lake Michigan, and can look over the other side, get view of town, and look down at part of the river channel thru town. ANd I got a photo of a lake freighter in the river channel. (Great Republic, 1981, 634ft)
TO ride back down, was in 2nd gear, engine braking all the way down.
At the bottom, I noticed didnt seem to be running well. On way home, didnt have the power, and was jitter shuddering.
Made it home.
Pipe 4 & 3 & 2 were hot hot. Number 1 pipe was barley warm.
Next day, this is plug 1.
Thick oily fouling. Clean it up, and back to its normal running.
now, I am not saying that downhill engine brake is the total cause of this, just that occassion probably added more to what had been accumulating.
Probably related to its oil burning, and puffing on decell, and blowing smoke when start if sits for a few days.
(I need to add oil about 175-200 miles. or sooner at highway speed.)
this is the engine I rebuilt in 2020&21 at 70some K.
I had shop check cyclinders which were in spec.
I replaced pistons with set from a fine GS member, and rings from Custom Cruise.
Had a used head rebuilt by another fine GSR member (lap valves, replace seals) who said had to take to shop to replace a valve guide that broke (I dont understand how/why).
Anyway, so is annoying that I went to that effort, and am yet dealing with oil burning. But I use the bike mostly for local rides.
Maybe I should check the other plugs.
Oh, local newspaper used my ship photo in the Weekly "Ships Log" artical.