Topic: Oil light gremlin..........................

[bjatwood]

Hi guys, my K3 7 fifty's oil light doesn't light up on cold fire. After riding and warming up the oil a bit, the oil light works properly. I am running Rotella 10w-40 in it. Does my sending unit need cleansing or is the sending unit needing replaced? There are no noises like oil starvation on startup or anything like that. Thanks for your replies 

[orkid1989]

from what I've heard its a common problem with the oil pressure sending unit going out. i would check it but sounds like it might need to be replaced. for my bike i deleted the sending unit and installed one of those small oil pressure gauges on the side of the motor instead

[brooze72]

Been having the same issue with mine this summer.  Works fine, then not.  I cleaned the sender & it was better, but not 100%.  Guess it's time for a replacement,  40 years old, after all!  Read on our site somewhere that there are cheap replacements from auto parts stores, do a search & you will find some stuff.

[HondaMan]

It comes and goes: when little grits get in the switch contacts, they can hold the switch open until they wash out. Oil grits are harder when cold than hot, so it can take a while to get them "crunched down" and the switch reliable again. They are hard to manually clean out!

You might want to avoid the 10w40 oils in a 750. It has always been spec'd to use 20w50 in warm weather, 10w50 in cool, and 10w40 in cold winter riding. I have marginal hot engine performance even with 15w50 in the summer: the shifting is much better and the engine far cooler with the real deal 20w50. Use only "motorcycle" oils, too, to avoid oil frothing in the sump, from contact with the spinning gears. Motorcycle oils have less detergent, so froth much less.

[bjatwood]

I did run Castrol 4T wet clutch 20w-50 for most of the summer, and then the darn parts store discontinued the oil! They said "we didn't sell much of it so we dropped it" So, needing a oil change and the temps dropping off, I decided to give the Rotella I've read so much about here in countless oil threads a try, and it does have the JATO rating for motorcycle use. My tranny liked Rotella mucho better the the 4T stuff. Smoother shifts and neutral could be found really easy at stop lights everytime. Sorry for another oil thread start, but I really had NO issue's with running the Rotella oil.....