Topic: Which oil for summer?

[78CB750F1]

I am doing an oil change on my CB750 F1 and was wondering what weight of oil members are using for summer temperatures (20 C and above)?  Are the different brands similar in quality?

[cmorgan47]

i've been thinking about this as well since i just finished an oil change with 10w30 only to read that above 59f (15c) it calls for 20w50.  i'd hate to waste the oil--and the $15) but it's pretty dang hot here right now.

[Dave K]

Well, I have been using 20w50 in my K3 since it was new. I use this in the hot summer months and use 10w40 in the cooler spring and fall months. It has worked for me for about 48,000 miles. Now since yours is a later model, you "may" be able to get by with a thinner oil. But, the price of oil to me is just not worth it to the motor. Pay me now or pay me later. JMHO For what it is worth, I have always used Castrol.

[andy750]

20w 50 im summer - Castrol as well. 10w 40 once it gets cooler. If you use 10w 40 in the summer and its constantly hot (like this summer) check it and you will see its like water....very thin!

Good luck,
Andy in Boston

[78CB750F1]

Thanks for the feedback - 20W50 it is!

[tramp]

in the summer 20w50
spring and fall 10e40

[nickjtc]

20w 50 im summer - Castrol as well. 10w 40 once it gets cooler.

Me too. I've always used Castrol over the years, latterly because it's all that the local Crappy Tire store stocks of 'good' m/cycle oil.

[cmorgan47]

so i switched to the 20w50 last night and though everything seems to be running really well, it took a while to start this morning....
probably at around 65-70f in the morning, but getting into the low 90s durring the day.

[nickjtc]

so i switched to the 20w50 last night and though everything seems to be running really well, it took a while to start this morning....

A more viscous oil might make the engine turn over slower, but I've never heard of it actually affecting starting.

Anyone got input....?

[cmorgan47]

no other changes have been made, and again at lunch today--in the 80s--harder to start than with the 10w40.

[cb650]

Do you have a elec prob creeping up now too.    Unless you made a drastic change like 10/40 to a straight 30 or 40 doubtful you'd notice.   I put straight 30 in my 360 and it fire first kick at 55 deg in morn.




                     Terry