It is not Rotella, and I would never be foolish enough to claim it is the best motorcycle oil, but I have been using Spectro conventional oil for the last 88,000 miles in the 750, which is going to turn over 150,000 original miles in 60 more. So I don't know if it is the best, but it must be pretty good.
Basically, this post says it all. Case closed. Mods, just sticky this on the front page and there should be absolutely no more discussion on the subject of oil. PERIOD
Seanbarney may be pulling my leg a little here, which is OK. However, I don't have a problem with oil threads since I might learn something. Oil technology has changed over the years, some good, some not so good for old engines. The kind of information I value is good old empirical data, the kind based on the real world, experimentation and experience. That is better than manufacturer's marketing hype, or something somebody remembers hearing or reading about on the internet somewhere. So occasionally I will chime in with some info from my experience with the 750 that someone may find useful. My experience has been that using Spectro changed every 3000 miles or so, with a filter change every other oil change leads to a long-lived engine. Could the same thing have happened with a different oil? Very likely,
but I know Spectro is good. So would anyone else who chooses to benefit from my experience. (Of course, I might just be full of #$%*. There is always that risk.)
I have three bikes that have accumulated a lot of miles that I have had since new or nearly new. The oldest I have had since 1977, the newest I bought in 1993. In the case of my '75 750F, it rolled over 150,000 miles this afternoon. The miles on the engine are original, it has not been rebuilt, not even a top end overhaul. It still uses less oil than many new bikes. Except for a 4000 mile flirtation with Mobil 1, I have used Spectro conventional oil in it since 1999. I have kept very complete maintenance records on the bike since 1988 when it had 25,000 miles on it. It may seem a little anal, but at one time I had 10 bikes in the rotation and I had a hard time remembering what I had done to which.
I agree with Hondaman about 10-40 vs 20-50 in the 750s. I used 10-40 HP4 a good part of the time when I lived in Alaska, but soon after moving to Idaho, I gravitated to 20-50. Hondaman lives in Colorado which has a very similar climate as southwestern Idaho where I live. It seems like it is usually very hot or very cold, with very little in between. I soon noticed with 10-40 on hot days, shifting became notchy, neutral hard to get to. The engine would be noisier and buzzier. This would become especially noticeable after the oil had a 1000 miles on it or so. With 20-50 Spectro, I never notice this, even when close to the 3000 mile change interval I use these days.
That has been my experience. I am aware few on here use their old SOHC Honda the way I do mine, but if you ride it regularly, commute on it nearly year around, take it on the occasional long trip loaded to the gunwales, it is likely your experience will match mine.
