Britbike forum Forums Thread Like Summary - TR5T smoking...

... only on left side, only when running on side stand. The bike does not smoke when riding. Engine is freshly rebuilt, including new valves, valve guides, and springs.

My theory is that oil is pooling in the left valve wells and running down the guides. Is this normal, or is too much oil getting to the rockers? Has anyone else experienced this problem?

In the early/mid 60s we broke in race engines by doing two laps of the circuit in practice using WOT and then rolling off the throttle time after time.
By the end of two laps it was ready to race-----that is-- ready to give it WOT as much and as often as you could.
And a dyno was something pressed up against a bicycle tire to get light!

Freshly rebuilt.....

How many miles are on it now and have you gotten on it hard enough in short bursts to seat the rings?

Has it been idled much before it's first test ride?

The reason I'm asking is that rings can refuse to seat if a freshly rebuilt engine is idled too much before the first test ride. An engine needs to be under load to help seat the rings.

I'm with the line of thought to keep it upright, avoid idling on the side stand, and run it and monitor changes- oil on spark plugs, look down spark plug bore with a tight beam flashlight and check head of piston for oil or carbon build up. Keep an accurate eye on oil consumption. If it's cracked and leaking oil, you'll know soon enough.

On the other hand, I simply do not tolerate my bikes smoking. Years ago when I was building up bikes, I had the projects in one shed and the workshop for repairs. At the time, there were about a dozen pre units in various stages of basketcaseness up to solid projectness all sharing the shed awaiting their turn in the shop.
Returning from a trip to town one day, I arrived to find a blueish cloud of smoke pouring out of the workshop. I immediately grabbed the garden hose and headed quickly to the shop. On my way, I noted two things- first was that I didn't see any orange glow of flames, and secondly that the door was half open- the blueish haze billowing out. I approached quickly and cautiously, peering through the fog to see what was going on inside. It was a sight I'll never forget!
On either side of the work bench, there was a toppled over project bike lying gangly on the floor- along with two or three oil bottles. At the work bench itself, three of the more complete projects were propping themselves up, idling away! Staring in disbelief, I watched for a moment as one of the bikes took a long hard swig off a two gallon can of high octane gas, then followed it with a chaser from a gallon of thirty weight oil.
"What the hell is going on?" I bellowed at the three bikes. Instantly they all dropped down to the ground and rested on their side stands. "Shut those dang engines off, you're smokin' us out!" I hollered, and with a final misfire from the Thunderbird they all went silent, looking right at me hanging their headlights like a bad dog. As I alternately scolded them for their stupidity and pointed out how bad just idling away and smoking out their exhaust was for their engines, I perused the scene around me. Five different motorcycles -two of which were completely crumpled up and passed out- the high octane gas can, the gallon of thirty weight plus all the empty quart size bottles, and not to mention, there was a Ziploc baggie with just a couple of nuggets of what used to be my stash sitting right in the middle of this mess!
Well, I made the barely stable threesome stagger themselves back to the storage shed as I uprghted and rolled the two collapsed basketcases back, all the while swearing that as long as I own motorcycles, there ain't never gonna be another time where they sit idling about on their side stands, sipping up good high octane gas and motor oil, just smokin' away!

I'll have to get with my son on that one; he has the bike back now, four hours away. But I believe he has ridden it a few times since it was returned.

As part of the second rebuild, the exhaust system was completely rebuilt. The header pipes are fabbed, TT-style. There are no mufflers, just six-inch baffles in the ends of the pipes. So the exhaust system is twice removed from the dripping oil episode.

Just for the heck of it, here's a photo of the bike with the fabbed exhaust: