T150v head scratcher

Onder said:

After some thinking: If the tappets are at 6 thou at 38 BTDC the only way a kick back into the carb
can happen is most likely a leaking intake valve. I pulled the head. No hung valves, no other disasters
seen. Two of the seats show tiny pitting. They should be cleaned up, the valves are all good as are the
guides. Two pistons were covered in black oily grease like stuff but they wiped clean with just a rag.
All I can think of is that we have a carb problem so I shall strip the carbs again and examine hoping to
find whatever I have missed. They are low mileage premiers. Did notice that the coils have 4 ohm resistance
when they should have 3.8 I think. TriSpark coils are 3.6. Spark, static, is not that impressive.
Jugs are from Neil Beadling .

Click to expand...

4 ohms is in the acceptable range (3.0-5.0) for Tri-0002. Not sure about the black box version. I know you double checked, time to triple check that the plugs are firing at the right time - sure sounds wrong. Also, check that the center of the rotor has not come loose if you haven't already.

Hmmm 13 May last post. And now it is 21 November! So what has happened?
I sent the head out to Pat Seager for overhaul although I was not convinced this was the trouble. But when I came back I was pretty sure it was off the problem list. Put a ton of time into checking the valve timing both using the degree method and the total lift method . Finally ended up using the factory markings despite the numbers being less than optimal. But there was no other way I could get closer. Used the same pistons and rings, they had about 3k on them and gave no trouble previously. Whilst putting the top end back together I collected the air cleaner bits (stock T150v with older KN element) from the bottom of the storage bin and noticed a puddle of oil under the element. Light bulb time: oil from a clogged element. Blew it out with the air gun.
Finished the reassembly of the engine, started first kick, road test went well. Idle not happy but that was the only complaint otherwise it pulls like a locomotive.
Have about 600 miles on it now two appx 150 mile nonstop rides included.
Far as I can see it was a soaked element, the stock setup breathes from the primary into the airbox. KN element was preoiled and
perhaps over filled primary vented and over loaded the already oil element.
Hard to believe but I found nothing else wrong. Live and learn.

Well at least you know. And you now know everything else is good.

Enjoy making it howl !