Sounds as if yours is broken off. The Honda CB750 is an air-cooled, transverse, in-line four-cylinder engine motorcycle made by Honda over several generations for year models 1969–2003 as well as 2007 with an upright or standard riding posture. 1979 CB750K (sold, 2012, but not forgotten). That is actually an old wives tale that somehow still lives on from the initial days of synthetic. However they were Chevy/GMC. I use Shell rotella T Triple as well. Shop with confidence. If you want to know, for certain, what is going on inside your engine, and how well your oil is performing, spend the money on oil analysis (~$20-$30). As a guest you can view the forum and photo galleries, but you have to register before you can post or view … Thanks, Steve 20 w 50 in the south, do not use  synthetic on a old motor unless you want to rebuild that engine, if you live in cold climate up north use an oil stick warmer, on 20 w 50, remember ive had this 1971 Cb 750 since new and never rebuilt runs great. After I got his 85 S-10 from him, and switched it to Havoline it was, so gummed up it would only hold 5-10 pounds of oil pressure. No longer would Honda be known as scootercompany. Diesel oil such as rotella has additional zddp in it. Standard motor oil these days does not because it wreaks havoc with catalytic converters. The CB750 "Four" offered a combination of features never before seen on a single motorcycle. Up north where the temps don't normally get as high, 10-40 was usually better as our mornings are usually not that hot and 20 weight can get pretty thick. I did not know that about aluminum.My 2001 Duramax has 235,000 miles and i have always used Rotella.Change the oil every 6,000 miles,because at 3,000 miles after oil change it still looks new.Takes 6,000 for it to darken. I use Mobil1 full syn ONLY in my race engines,haven't found any other thats cold flows as well and i leave the line at 140 water temp so i need that. And how much? Just automotive is fine. Not even, for free on a dare. The biggest cause of engine wear in motors like this is lack of zddp. I know a lot of people are running the Rotella, but I have seen the high detergent oil eat up aluminum engines. I use shell rotella t6 5-40 in all my bikes. I should mention that my winter has involved cold morning cranking in 40 degree weather. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe. I hate to tell, you, but the dirtiest, nastiest, and gummy engines I have ever worked on were running Quaker Cake oil. Yes it has more detergents but not enough to cause damage, after all, a lot of new diesel engines have aluminum in them nowadays and this oil is very popular. 10w40. Find great deals on eBay for cb750 oil. yes thank you.Does have to be for bikes like 4T or just automotive regular? Did not want to spend $1,900 on a $2,000 truck. Network/Field Engineer. Put 375,000 miles on my last truck. Life is not about the number of breaths, you take, but the moments that take your breath away. CB750.com is dedicated to the Honda CB750 SOHC and DOHC motorcycles and to their owners who love to ride, restore, and customize them. hi I would like to know what oil to use in 1974 cb 750 k.I have download manual but fail to locate exactly what sort of oil.It call for 10w40,but it is motorcycle oil or dyno automotive?I do not want to use synthetic.Thanks. No, the threaded oil cap should have a dipstick molded on the bottom of it. Change every 3000 miles. In hot climates, especially years ago, this was the way to go. You can use a standard 10-40, I used to. I would always ask what kind of oil they were running, and the cleanest engines always had Texaco Havolin in them. It is hard on aluminum. Engine did not use any oil, and was clean as new inside. However, this oil is very easy to find in any auto parts store, it's the one in the red container, so you can look at its viscosity in your next trip to the Autozone. There's really no mark on the dipstick that I can see. I know a lot of guys swear, by the Rotella T oil. http://en.wikipedia.org/wiki/Shell_Rotella_T#Motorcycle_usage. What type of oil should I put in my 1979 cb750 dohc? It is still yellow at 2500 miles,so I stretch the changes out longer.I have been using the Rotella that Sarge recommended in my bike.All good so far. Gas mileage has been good at 43 mpg. Chilton's manual says 3.7 qts. Its great stuff and it's meant to take a beating. His John Deer riding mower was dead, and burning oil in one summer, and his pickup, and van were both burning oil in 60,000 miles. The destination is just to get gas! Engine oils of old 60 days had good doses of this stuff. travel 96in. I use Texaco Havolin 10w 40 in all my bikes, and change it every 3000 miles. Areas in the south mainly. Only let the truck go because the trans was starting to slip. Irony is my Dad used to use the crap. Rumor has it the extra slippery stuff in there will cause clutches to lose their clutch-ability (if that's such a word). At the heart of the CB750K was an inline four-cylinder engine with a single overhead cam, four carburetors, four-into-four exhaust pipes. But the different in engine smoothness, shifting ease, and oil chain intervals more than made up for the slight additional cost. Life is not about the number of breaths, you take, but the moments that take your breath away. Quaker Cake, and Arco are the two oils I would never use. The big thing with oil is to change it regularly. I also found that the bike runs cooler after the Seafoam. I use Rotella in everything but the Impala,my highway car. Oil type and amount?. It produced 67 horsepower at 8000 rpm which was 15-percent more power than BSA's new 750 cc Rocket 3even though they weighed … it gets right at 2 mpg better using Mobil1 full synthetic. Had to drop the oil pan, pump, and pickup off to clean them. Where can I get Castrol, for $2.50 a quart? I have read on other forums that the Energy Saving feature of most automobile motor oils will play havoc with the clutches on the CB750 style motorcycles. What type of oil should I put in my 1979 cb750 dohc? If you live in a hot area, a 20-50 works too. It is often called the original Universal Japanese Motorcycle (UJM).. I use the Rotella truck oil in my Duramax and every race engine I ever had. I agree with TOOLS. That's what I always use. I was getting 500+ passes on bearings vs my buddies 3-400 who were using the latest "race oils". Haynes manual says SAE10W/40 3.5 litres at an oil change, 4.5 dry. I can get it at walmart, but it is not synthetic. my father has a 1971 CB 750 k and he's always used 20w 50 caster oil motorcycle, cause of the heat they put out, and he said stopping and waiting at red lights they build up a lot of heat and the heavier oil keeps the motor cooler at all times ,but in winter months takes a little more cranking cause of the thickness.