castrol gtx 10-40 engine oil

anyone have any problems with or have anything to say about running Castrol GTX 10-40 in an 84' kz1000p ?

As long as the oil does not contain any "Friction Modifiers" in it, I suppose OK.

Best Oils To Use In Your Bike (Just My Opinion)

Engine oil : The commercial grade oils are clearly superior to the mass market oils. For the best protection in your bike or car, use Shell Rotella Synthetic, available at Wal-Mart in blue containers . For the best petroleum oil you can buy, get Shell Rotella T, Mobil Delvac 1300, or Chevron Delo 400, available at any auto parts store. On the back of most oil cans is a circular stamp with the certification. Avoid oils that say "energy conserving" in the bottom half of the donut.

These oils contain friction modifier additives that could cause clutch slipping over time. The EPA mandated certain gas mileage, so the auto makers turned to the oil manufacturers who came up with friction modifiers of the oil to meet these new standards. All XXw-20 and XXw-30 oils are energy conserving, and should not be used in your motorcycle. Don't buy any oil additives like STP or Slick-50. Here's several listings on all about oil justifying these conclusions.

The Recommended Synthetic Oils :

Shell Rotella Synthetic
5w-40 Delvac 1 Synthetic
5w-40 AMSOil AMF Synthetic (pricey, but it’s your money)
10w-40 Golden Spectro Synthetic
10w-50 Motul 5100 Synthetic
10w-40 Mobil-1 Synthetic
15w-50 Mobil-1 MX4T Synthetic

The best synthetics are: (in no particular order)

Shell Rotella-T Synthetic 5w-40 (blue container is synthetic, not white which is dino), gallon at Wal-Mart.
Mobil Delvac-1 5w-40 (grey container is synthetic, not black which is dino), gallon at Petro stations, gallon at Farm and Fleet.
Mobil-1 SUV 5w-40, qt anywhere.
AMSOil AMF 10w-40 synthetic motorcycle oil. (again, pricey)
Golden Spectro Supreme, (no price).
Motul 5100 Ester, (no price).

Mobil-1 automotive oils all contain small amounts of moly - about 100 to 200 ppm. This can cause clutch slippage in some motorcycles. I've only heard of this being a problem in Honda Shadows.


The Recommended Petroleum Oils

Chevron Delo 400 15w-40
Delvac 1300 15w-40
Shell Rotella 15w-40

The best petroleum oils are: (in no particular order)

Chevron Delo 400 15w-40 (blue container) gallon at any auto parts store, gallons at Costco.

Mobil Delvac 1300 15w-40 (black container) gallon at any auto parts store, gallons at Sam's Club.

Shell Rotella-T 15w-40 (white container) gallon at Wal-Mart or any auto parts store, gallons at Sam's Club.

Castrol 15w-40 (Green container) gallon at Wal-Mart or any auto parts store, gallons at Sam’s club.

Don't do it. Find an oil that shows the JASO-MA rating on the bottle; there are plenty of them available both dino and synthetic.

The ingredients in oils have changed over the years. For example, today's Castrol GTX oil (and pretty much all other AUTOMOBILE oil) is not the same as it was in the 1980's. Back then it worked great in KZ bikes. But, things have changed. Early AUTOMOBILE oils contained zinc phosphorus compounds (ZDDP) to protect engines from metal to metal contact. This was good for engines, but it was found to be destructive to catalytic converters. Consequently, in AUTOMOBILE oils ZDDP was virtually eliminated and replaced with different chemistry generically referred to as "Friction Modifiers." These work fine and offer good protection for normal AUTOMOBILE engines. However, today's AUTOMOBILE oil "Friction Modifiers" are destructive to wet clutches. KZ bikes (and many other brands) have wet clutches. As a result of these oil chemistry changes a distinction needed to be made between those oils which are suitable for wet clutches and those which are not. That distinction was documented by the Japanese Engine Oil Standards Implementation Panel (JASO). JASO developed a number of different oil specifications for different applications. The specifications that apply to 4 stroke motorcycles fall under the "4T Specifications." Within the 4T specifications the JASO MA class oils are specifically formulated for 4 stroke motorcycles with wet clutches.

Using oils that are not designated as meeting the JASO-MA standard may be destructive to KZ clutches. Here's a link that may be helpful:


www.oilspecifications.org/jaso.php

it might be my 40th choice...leave it for john force to use.

84kz1000p wrote: anyone have any problems with or have anything to say about running Castrol GTX 10-40 in an 84' kz1000p ?

I ran it for many decades, back then it was the best available. I think it's OK oil, the 10-40 grade should not have any moly in it. I think Rotella is better, but Castrol is pretty good.

I used Castrol in the past too for many years and was happy with it, but they changed the formula to accommodate catalytic convertors, so I switched to motorcycle oil. BTW, Rotella is JAMO-MA rated so I agree that it is a much better choice. Ed

I ran it the vast majority of 160,000 miles on a KZ650. I'll reinterate my story in short. I rode for 100,000 miles or so and the engine was clean, then even at 140,000 or so it was relatively clean. At 160,000 despite changing oil every 2000 miles since new, engine was so full of sludge oil would not drain. I went to drain oil, took off the drain plug after warming the engine and 6 oz of grease oozed out and that was it. Engine was expired to say the least. To this day I still believe Castrol went downhill somewhere between SE and SM or whatever for motorcycles and don't recommend it. This was all before MA standards were ever even invented, back in the old days no such thing. I still don't care about MA standard, but won't use castrol again. Still I got 135,000 without a rebuild using Castrol, so if that's considered high miles then yes it does the job. I think new oil has come a long way. This was years back.

The mineral oil base that composes most of the oil has not changed, the additive package has changed in all car oil. They no longer have the ZDDP additive so beneficial to reducing start-up wear and cam lobe wear. The energy conserving oils have "slick" additives like moly which will screw up a wet clutch.

In the early 80's, Castrol GTX was the only oil with additives that were strong enough to work in a bike. My dealer used it exclusively and said to use nothing else. Today, there are "commercial" rated oils like Rotella that are certified for diesel service with strong additive packages which will work in a bike.

You can just buy "bike" oil, but like anything labeled for use in a bike, it's priced at about 3X what it's worth.

Interesting, so what are the thoughts on the other Castrol product...Castrol Activ 4T (if you get that over there in the US)

I haven't seen it where I live, but it should be fine for KZ's because it meets (exceeds) the JASO-MA standard.

www.ils.co.nz/b1webtools/assets/downloads/SKU%20TDS/4101146.pdf

Pretty much for any oil designated with 4T Motorcycle oil designed for wet sump clutches... It normally meets the specs just fine.... Use this for engine break in periods...

Then switch to Mobil 1 synthetic...



OR.... :whistle:

I use Amsoil 10w-40 exclusively. I ride year round, sometimes it's 110 degrees out, sometimes it's 30. I also get my oil chemically analyzed every other change.

Oil is the lifeblood of these bikes.