I got a 1982 XJ400 Japanese Domestic Model it ran fine 8 years ago, but has been sitting for 5 years now. Just completely cleaned and rebuilt the carbs, checked the valves and holds a good idle. CArbs syncd and it has great throttle response while in nutural on the lift. However when under a load (test ride) I can run faster. I can just get it to 60KM on a downhill. doing a compression check tomorrow. Any other suggestions????????/