I asked Mistral racing about running in a new Hayabusa engine and they said to put a 20-50 mineral oil like Castrol GTX. This supprised me because I have heard that bike engines need bike oil because of the clutch or something like that.

What do you guys recon?

Jason

Try these Guys. They seem to know most things about oils

http://www.opieoils.co.uk/

Just go to the contact us section & ask the question

I seriously wouldn't do that.
Who did you get to speak to- the cleaner?
Castrol GTX is super luby which isn't what you want when it's a wet clutch system...

Not all bike engines work well with Fully synthetic. I ran a GSXR with fully synthetic, and the clutch slipped like a b1tch!
Ive tried loads of oil in different engines, and to be honest, i find mineral to be the best. Currently ive got Semi Synthetic in my TLR1000, but synthetics seem to break down quicker. I would stick with what the manual says, that way, its tried and tested and also sanctioned by the manufacturer. Its the viscosity that needs to be right, from there, you can check regularly to see what the oil is like after every run, or even send it for analysis (££!). For a BEC, personally, an oil change every three to four months would make sure tha engine was looked after, and that the oil is good.

[Edited on 16/8/08 by MakeEverything]

When he told me to use something like 20-50 GTX I did tell him that people have told me to use a proper bike oil and he said it's not needed, he said that for running in, a good mineral oil like castrol GTX is good to use because the synthetics don't allow the engine to run in correctly. I don't know what to stick in it!

Jason

Are you sure he didin't say Castrol GPS? That is a bike semi synth oil i.e. a mineral based oil.

For running in all you need to do is put in a Bike specific mineral oil of the correct viscosity. It doesn't have to be top quality as you will be throwing it away after a few hundred miles.

After that I would personally put in synthetic oil as it will reduce the wear in your engine and last longer. If you put in new clutch plates at any time be sure to soak these in normal mineral oil for 24hrs first. You then won't suffer any slip issues.

- Paul

Yep 110% sure he said Castrol GTX 20-50 mineral oil. I confirmed it with him as Ive heard different.

I'll get bike mineral oil for running in then.

J

i think mineral oil is supposed to be used for running in as it helps the piston rings 'bed in' to the bores, as in enables it to create a good seal, if you use synthetic then it can 'polish' the bores and not create a good seal, hence lose compression, or something like that... to be fair when your running it in it shouldn't matter wether it's car or bike oil as you shouldn't be putting it under that much stress and it will be changed for some proper stuff after a few hundred miles anyway...

Have a look round the service bay of a bike shop and see what they use from the big tank in the corner.
Running in a bike engine is not the gentle affair that running car engines in used to be, they actually work better if driven hard during the early miles.

[Edited on 17/8/08 by Peteff]

Whatever Rob at Mistral says, that is what you should do.
I've no connection with Mistral, other than being a very happy customer. His engines have taken me to many a sprinting class record.