EC 125 Lubrication enquiry
 

Hi All,

My 1st post, only joined today.Also my 1st Gasser,:) I brought a 03 EC 125, a little tired looking but seems to be sound,had to replace the front wheel bearings & spent most of today trying to sort out the electrics, lights,horn, speedo etc as it all came in a box

I haven't ridden a stroker in over twenty years so I'm on a fast learning curve,:eek:
I ride green lanes (local trails) and also compete in hare & hounds. Currently ride a Yam WR250.

Can anyone say the best fully synthetic oil for the mix & also the best gearbox oil bearing in mind my intended use?

By the way terrific forum, spent most of the evening looking through it.

Thanks

Will

Any good synthetic @ 32:1 in a 125. We use Amsoil. For the trans the Shell Rotella 5w-40w works great like in the bigger GGs. Not sure what you have in the UK thats equivalent, but a diesel oil of the same viscosity. Is Rotella called Helix in Europe/UK? Otherwise any good MC trans oil is fine.

Putoline MX7 is good and easily available in the UK for the engine and their Light Gear Oil for the Gearbox. I run 50:1 on the 300. If I was you use whatever the manufacturer's recommended mix. Sometimes running too much oil is actually worse for the engine. Forget why but remember reading an engineering paper on it. The

When I strip my engine MX7 seems to be clinging well to all surfaces and there's very little carbon on the piston or head. The Gearboxes need a very light oil or the clutch drags.

Please post a link to that paper. Many tests have been done proving that as long as your jetted right, more oil = more power, down to 16:1 or so. The less time the oil is in the motor (higher RPM, faster pump) the more oil you need.

I'll try and hunt it down. May take me a few days. It wasn't about producing more power just that wear doesn't decrease by loading up the oil beyond a certain point. Once you have enough a little more makes no difference. Then when you have way too much wear increases again.

Why is more oil more power?
Not that I want more power but interesting - that seems to suggest that putting 2 stroke oil in a 4 stroke would be a good idea.

Better ring sealing, better heat transfer. This providing that jetting is correct for the mixture. I run 36:1 Amsoil in my 250. Amsoil suggests 50:1. I have no spooge, fouling, or carbon buildup issues. The bikes makes great power and the top ends look great when torn down.

Glenn,

I can't find it now! Googling found many articles agreeing with you on more oil is good but none seemed to be based on proper lab research. Maybe you're right but I can't grasp how once you have enough to create a proper oil film on the appropriate surfaces that any more is going to help. I am assuming that the bike vendors recommend "enough". Surely as long as you have the metal properly separated, separating by a few more microns wont matter. But ... if you're not getting proper coverage at the lower strength mixes I agree logically more wear.

The thing about time in the motor I don't think is related to rpm - ok it spends less time there but you're putting more through at high rpm. Unless the throttle is suddenly closed which is when some road premix machines used to seize. I often pull the clutch on 2 strokes when on a long descent.

It absolutely is related!

Think about the fact that it takes x amount of time for the oil to separate out of the mixture in the lower end as it vaporizes. The faster you move it through (RPM), the less can separate out.

Awhile ago I talked to Jack Bondus about this, who told me about an interesting study conducted using premix oil at different ratios with a radioactive tag. The amount of activity is proportional to the amount of oil, so it could be traced completely through the engine. Results were that the best ratio was around 32:1 - 36:1 for a 250 2-stroke race bike. Next time I talk to him I'll see if he has a link to this as it sounded interesting.

Seperate? When does it seperate & what is the cause?
Does the crankcase compression force it to seperate? Why would it?
Or are you saying the vapourising effect of carburation and turbulence seperates it?

I always thought it seperated purely because it's stickier than fuel and adheres to metal more. Most burns with the fuel but enough adheres to metal to do the job.

I'm quite interested in this so any links you have to reasearch would be interesting if it's from a proper scientific study. You've convinced me to try a richer oil mix though. :)

The mixture is atomized in the carb, and vaporized as it enters the engine. The oil can not vaporize like gasoline so it separates. Some must remain in the lower end to lube the rod and main bearings. The holes above the mains in the cases are to allow some of the oil that has separated to run down and feed the bearings. If the velocity of the incoming mixture is higher, it makes sense that more oil will be swept into the top end and less will separate in the lower end, don't you think?

I have no idea who did that study, it was just brought up in a conversation. Maybe do an internet search. Being involved with some radioassay tests at work, I can see this being plausable.