Bikey no likey the 20-50

Changed my oil and put in 20-50 Castrol. Takes forever to warm up now. Oh well it'll do until August.

I wondered about that when you said you were going to use that oil...makes that much of a difference,eh.:huh:

Thats what Ive always used, what do you guys advise to use ?

I used 10w40 in colder weather, 20w50 in hot summer weather. Did that for 20 straight years on the KZ650 using Castrol GTX. Finally the engine was too sludged up to even drain the oil so I abandoned the engine as well as GTX. Now use 15w40 Shell Rotella diesel oil with no problems in 40,000 miles. No matter what weight oil I used I could tell no difference except in cold starts. Don't use 20w50 in the winter. I'm going 10w30 next winter. 15w40 too thick for cold weather.

dumb question, how does the oil change how a bike warms up, the oil is going to get hot at the same rate, the viscosity is what changes.

Different viscosity = different rates of temp change. Instead of viscosity, think density, the more dense something is, the longer it takes for a temperature change to occur.

PFC FNG wrote:

Different viscosity = different rates of temp change. Instead of viscosity, think density, the more dense something is, the longer it takes for a temperature change to occur.

I live in the California High Desert. Kind of like the surface of Mars. Cold in the winter (well, cold for CA), and hot in the summer.
I like 10W-40 in the winter, and 20W-50 in the summer. Warm up time always depends on how cold it is when I start up. In the summer, it's about 100° in my garage, and I need maybe 2 - 3 minutes before I can close the choke. In the winter, maybe 5 - 6 minutes.

RonKZ650 wrote:

I used 10w40 in colder weather, 20w50 in hot summer weather. Did that for 20 straight years on the KZ650 using Castrol GTX. Finally the engine was too sludged up to even drain the oil so I abandoned the engine as well as GTX.

That's surprising, back in '79 when I bought mine new the dealers ONLY used Castrol GTX. I used it exclusively until I switched to synthetics about ten years ago. never had a sludge problem. GTX was the only oil back then whose viscosity enhancers could handle the shear stress that the bike transmission puts on the oil.

BSKZ650 wrote:

dumb question, how does the oil change how a bike warms up, the oil is going to get hot at the same rate, the viscosity is what changes.

I don't think it actually changes how fast the bike warms up. I figured he meant it affected how it ran like how long it took the clutch to start working right. When I ran 20-50 the bike would jerk when I put it in gear while it was cold.

Ive been using 20/50 Catrol GTX in everything for 35 years with no sludge problems. Winter riding in Montana isnt a problem, you dont do it. There are times you could but they use cinders on the street corners for ice. Think ball bearings on every corner. Ive ridden Christmas day at 29 degrees once just to say I did it. I know guys who use 10w/30 in 1100 Suzukis with no problems down south. I can see where yould really feel the difference with oil weights in a 650 though

It's still pretty cool here and I leave for work at around 1030 at night. Before I changed the oil when I started it I could get it to rev with chove lever just like normal. Now I start it and I can only get it to about 2K rpm with the choke lever. I let it run while I put on my helmet and gloves. I have to leave the choke about half on and can feel it stumble for about 3/4 of a mile. Then it's all good. In the morning it's still about 50 degrees when I leave work. Before I changed the oil all was normal with the clutch and warm up times. I'm not asking for a solution just listing an observation. I'm sure things will be different when it warms up to a hundred next month.

Oils have come a long way since the 70s. 10/40 should be fine for pretty much any street setup. The lower viscosity will get to the top end quicker on cold starts. Maybe if you're in a situation where you're stuck in stop and go city traffic for extended periods of time on a regular basis....then the 20/50 could be a better choice. An oil cooler is the real cure for those situations or performance engines...

If you can afford it, Joe Gibbs makes and excellent break in oil that adds some lubricaion punch. It's fine for regular use as well.

I suggest using it to break in all the engines I build and I know guys that continue to use it after break in.

Larry C