Oils in the U.k

[supersaki]

Ok folks,I am new here and i realise that this question may have many answers.
What oils are you guys using in your engines?
I have just purchased a new engine and i am about to fit it and give my bike a new lease of life.However after reading some old Suzuki bulletins and asking around I am a little unsure of what oils to use.
I am aware that this may open a whole can of worms,but it would be interesting to hear you experiences in this area.
Does anyone know what the original criteria of the oil was and why?
Obviously oils today far exceed the demands of 1975,but to what advantage in an Re5?
Is anyone using a modern synthetic 2stroke oil in there injector system,why not ?
Any help will be greatly appreciated ,thankyou.Roy.

[ziggystardust]

Hi Roy and welcome.

Most U.K. owners including myself use Castrol XL 20w-50 oil in the sump and metering tank.

It can also be used in the gearbox but personally I use a modern oil specifically for wet clutch gearboxes.

As it's a mineral oil it's more suited to the RE5 with it's low ash deposits in the combustion area, synthetics from what I have read are not as suited for early rotaries.

Having said that there may be some owner's that do use synthetic or modern oil and have had no problems but personally I'll stay with the proven oil.

You can get it from here
www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9014107&contentId=7027099#7094382

[gokart]

Hi,
I don't think use synthetic 2 strokes oil is a good idea. This oil is more fluid than for example a 4 strokes 20W50 oil and you'll have to reset the metering pump otherwise the rotor will be "over lubricated". This means a greater oil consumption, more smoke emissions and sometimes an oil fouled spark plug. Remember that RE5 oil pumps have been designed for a standard 20W40 or 20W50 fluidity oil. It's the same problem with 70's 2 strokes bikes.

A friend of mines who used synthetic 2 strokes oil in both his 2 RE5 oil tanks suffered a big oil consumption. He also had "black oiled" spark plug and the same as the end of his mufflers. After coming back to the normal 20W50 oil, now everything is normal....

Alain

[supersaki]

Hi,thanks for the info,
You say that its well proven in the Re5?
Have you covered hi mileage using it?
Does it burn cleanly ,does it produce lots of smoke?
The reason I ask is that 3 different engines that i have are showing low compression and after close inspection,show badly worn combustion chambers(plated area NOT side plates). Unfortunately I dont know what oil that they have been using,but I do know that
they have been getting plenty of it.(no delivery issues)was it oil type,who knows!
Do you know why Suzuki where so specific about oil to be used.?
kind regards Roy

[ziggystardust]

The recommended oil was set by Suzuki in the 70s, they had their own RE5 rotary engine oil but later announced that Castrol GTX 20/50 was o.k. to use, as Suzuki don't make oil it may well have been that in the first place.

This classic oil is still available worldwide but may be named slightly different from country to country, I'd guesstimate that over 90% of owners use this oil without any problems.

I use it and have covered over 5k miles with no problems, I have two RE5s, when I start one there is a little smoke which disappears as it warms up, this is acceptable. My other has a new engine and there is little to no smoke on start up, once warmed up and running there should be no smoke unlike a two stroke.

If you research engine oil for the RE5 from the archives you will read from a broader and bigger input that will convince you as to which oil to use. It's been covered a zillion times.

[steveuk]

I'm with Lee on this one I use Castrol XL 20w-50 oil in my RE5's because of its low ash content which keeps the apex seals cleaner and therefore moving freely, higher ash content oils can build alot of carbon up and this will foul up the apex seals and in turn make them stick in their grooves.

Steve

[supersaki]

Hi Steeve,
I make reference to a hand written note on bulletin RE-11 dated sep05 1975 witch states the use of three oils.
1.RE oil
2.Shell Super X 10w-20w-50w(is this an early multigrade?
3.Mobil Super Oil 10w-40 (NOT 20-50)
Then written in red ink DO NOT USE CASTROL
Im confussed!!!!
I only have bulletins from the U.S up to no16.
Are there any more bulletins which give more oil options?
Please wax lyrical on this subject and if you guys say that casrtol 20-50 is the way to go then castrol it will be.
Thanks again any stories and experiences greatly received
Roy.

[steveuk]

i think NO.16 was the last bulletin, Sam the all time authority on RE5's also said to use castrol 20/50 because of its low ash content.

steve

[suzukied]

I use high quality fully synthetic two stroke oil in my bike, my logic being that in a two stroke it is designed to lubricate the rings (in this case the rotor tips) and to be burnt and is low ash. My RE5 doesnt smoke, the silencers do not drip oil, I have not fouled the plug and I have done more than 500 miles this summer (not enough I know) without a hiccup.
Each to their own I guess. i dont really understand the logic in the use of Castrol XL as it is not designed to be burnt in a combustion chamber. Anyway whatever keeps the bikes on the road is the important thing.

[Jess]

The ONLY recomended oil for the Re5 is Castrol GTX 20-50 for the engine and sump as it has the lowest ash content of any commercial oil.

You can use it in the transmission as well although some prefer to use a different oil. It makes it easier to use Castrol as then you only have one oil for the entire bike, as Castrol is available literally everywhere in the US.

As to being "Proven"... Is 35 years and countless miles good enough? Suzuki sold "Rotary Engine oil" at the dealerships. It was Castrol GTX 20-50 branded and packaged for Suzuki.

I always wonder about why people get so hung up on oil. Why do you want to spend 5 times more money for some whoop de whoop exotic oil. Do you think it will make your motor last 100,000 miles? They already last 100,000 miles with proper care.

If you believe that they are so much better, do you also think there is some magic crap you can pour into your engine that will make it so you can drain all the oil and still run it forever like the late night infomercials? I have seen it on TV, but I'm not gonna do it with my engine...

The FTC (federal trade commission) made a ruling in the late 70's due to manufacturers (Specifically H-D) listing their branded oil. (Example, use only H-D type PQZ oil in Your pan/shovel widget). Harley did not make oil... They had it packaged by an oil manufacturer, and sold it for three times what you could buy it elsewhere for.

I won't even get into the synthetic/two stroke argument... Except to say refer to the first line of this particular post...

Use what you want, engines are expensive to replace. Maybe it will work fine... Maybe not. I am not willing to risk a motor on a well settled question.

Best,

[ziggystardust]

Yes keeping these rare bikes on the road is exactly what it's all about and if you want to use synthetic two stroke oil then I'm sure it may well work but as you say you have only covered 500 miles using it so you would need to put thousands of miles on your bike before we could agree that you are onto something here.

Using Castrol GTX or XL as it's known today is the type of oil Suzuki had in mind when they developed the engine rather than using a two stroke oil, I have heard of other owners using two stroke oil but mainly through ignorance and don't know how the engines performed, depends how many miles you do I suppose. No one as I know has had a failure through using classic Castrol 20/50 oil.

Going back to the seventies I had a couple of Mazda RX3s and these would take the engine oil from a dirty sump. Also out of interest when I took delivery of my M model and lifted the seat for the first time in over thirty years there was a used spark plug and a piece of paper in the tool tray, hand written on the paper it said 'use Castrol GTX in everything', so one might say something like if it ain't broke don't fix it, but we do need to move on and if synthetics prove to be a better performer then that would be a step in the right direction. Keep us informed but personally I'll stick with the Castrol mineral oil.

www.mazdatrix.com/faq/synthetc.htm

[Jess]

Forgot to mention...

I have personally seen mikiuni metering pumps that were utterly destroyed from using two stroke oil.

Two stroke oil has the consistency of water. while it may have the same viscosity ratings, it is much lighter.

Suzuki engineers did not have synthetics or the current oil selection. They designed the pump to work with what they had... the "thicker" castrol dino.

If you have removed your metering pump and run premix... fine. Again, I dont suggest it, but your choice. If you are using the factory metering pump, two stroke and synthetic have the possibility of making the brass gears in the pump eat themselves.

Again, Your bike... you choose.

Best,

[supersaki]

Hey guys,
Interestingly you say that Reoil was made by Castrol?Then why was it not a recommended oil as an alternative? (or was it later?)
As far as pumps being damaged when using 2stroke oil,these are the same pumps that Suzuki use in there 2 stroke engines and ive never seen one using brass gears, and my re5 has no brass gears in its pump(im confused)

Thanks for info
regard Roy

[Jess]

I am speaking from my experiance... I have worked on and owned several hundred re5's in the last 25 years.

I purchase Castrol in 55 gallon Drums as that is all we use here at Rotary Recycle. For the record, I have no stock nor financial interest in Castrol.

One thing I did note in re-reading my last post was that I said brass gears, They may very well be bronze, although bronze is typically not used in gears...

So for the sake of argument, I will now refer to the gears as brass/bronze, as I am not a metallurgist.

I have personally seen many Re5 Mikuni pumps destroyed. They have bronze/brass gears inside. Every pump that I have ever seen that ate itself was using two stroke or synthetic oil when I disassembled it.

Mikuni built many pumps for two strokes, They also built pumps for many other bikes, including the Hercules W-2000 oil injected models. They also built pumps for Mazda. It does not mean they are the same pump as the Re5. I would be curious as to which bike or bikes use the exact same Mikuni pump as the Re5 as they are getting hard to come by, and therefore expensive.

Taking apart an Re5 Mikuni pump is a no no. They were indexed at the factory. Once you pull them apart, you may not get them back together properly as there are no visible index marks.

If you read the link that Ziggy provided, Mazdatrix, a respected rotary specialist, recommends... You guessed it Castrol GTX 20-50.

As I have said throughout this thread, "your bike, your choice", I stand by my previous posts and am done with this thread.

I will continue using Castrol until they stop making it. If they stop making it, then this discussion will have some merit. In my opinion, this issue is well settled. Good luck with whatever you choose.

Best,