Siebenrock power kit for R90/6; Completed! Thoughts on re-torqueing head?
Cylinders/kit arrived on Tuesday. Wednesday I cleaned the garage/work area to operating room cleanliness (it needed it). Thursday I installed the kit. The people at Ted's Beemer Shop were beyond helpful with advice. I torqued the head nuts down in 3 stages, 15, 20 and finally 25 ft. lbs. On Friday I got everything dialed in and went for a ride. In the 15 or so miles we rode I noticed that it didn't feel quite "in tune" yet. However while riding, the donut on the Dyna 3 pickup slipped off the advance and I had to borrow a riding buddy's bike to go get my van and haul it back to the house. I used red loctite on the small threads to insure that that would not happen again. While continuing the tune up process I noticed that it would spit back through the carbs. That denoted a lean condition but there were NO air-leaks. I decided to let it cool down and the next morning I re-checked the valve clearance. What I found was tight valves all around. I then re-checked head torque, it was way off. After re-torquing the heads and re-setting the valves it ran PERFECT!
Tomorrow I will have about 100 miles or so on it. I want to change out the oil (cheapo Valvoline 10W40) to higher quality 20W50, either dedicated motorcycle oil or racing oil. I have decided not to use synthetic for at least the first 2000 or so miles. I intend to change the oil again at a 1000 miles. Should I re-torque the heads tomorrow or should I just wait and re-torque them at 1000 miles? I read a really interesting article a couple of months ago somewhere that probably answered my questions. I have been scouring the Snowbum articles but I haven't found it there (yet). Also, do I back each nut off all of the way before I re-torque or just partially?
By the way; after only 2 days of riding I can tell you that the Siebenrock kit turns it into a completely different motor. The most shocking revelation? Significantly LESS vibration. It was always a slightly peaky engine with real power only coming up after 4000rpm. Now, it seems to pull HARD from 2500rpm on up. Rolling on the throttle at 75mph it kinda feel more like my R1200RT, cool.