Some tech questions

[Disciple]

I just got my KX 250 rebuilt on the bottom end (after an engine seize ).. piston was fine, but needed a new crank.

I am taking it out this weekend for a little semi-easy run - I bought some Spectro 4 SAE 10w40 engine lube and threw that in the crankcase (on recommendation from Sportszone Suzuki). Does anyone know some good tips that I can do until this weekend to maybe ease it in a bit? Last thing I want to do is blow out my engine again after just getting the bottom rebuilt.

Thanks

[Disciple]

Request deletion of thread ... dummy above me posted in wrong forum...

[cowpoos]

don't load the motor to much....lots of gears....not much throttle...do that for a few hours and the bearings will be bedded in fine...and then change the oil and filter....and give it arseholes!!!!!

the oil thats in it is it mineral or synthetic???
Its often better to use mineral oils to run a motor in...coz it will wear off the filings...and develop groves better....and switch to synthetic after run in...

[Disciple]

I am using mineral oil at the moment. There won't be much worry about running it too hard.. I am novice at the moment so I tend to granny along for the most part.. nothing too shocking by way of tricks, speed, etc..

Thanks for the response, I appreciate it

[The Stranger:Me]

Its often better to use mineral oils to run a motor in...coz it will wear off the filings...

I am intrigued, how hell do you reco your engines?

[F5 Dave]

don't load the motor to much....lots of gears....not much throttle...do that for a few hours and the bearings will be bedded in fine...and then change the oil and filter....and give it arseholes!!!!!

the oil thats in it is it mineral or synthetic???
Its often better to use mineral oils to run a motor in...coz it will wear off the filings...and develop groves better....and switch to synthetic after run in...

Sorry, I am going to call Cow Poos on CowPoos, um, . . . well you know what I mean.

Change the oil & filter? It is a KX, the gear oil is only for the gearbox, clutch & the Right hand main bearing. The crank is sealed off from the gearbox.

The gear oil will have no bearing on the crank save for lubricating the RHS bearing.

However it is a good oil & the gearbox will appreciate it.

The ‘bottom end’ being the crank + LHS main bearing is lubricated by the 2 stroke oil mixed with the petrol. As is the bore.

Bearings don’t need to be run in. In fact it is impossible. Bearings are already machined to the closest specification. Have a look at a ball bearing or a roller bearing & ask how it could possibly be ‘rounder’? Further -bearings work by running on a thin boundary of oil, never touching the metal races they run in. So bearings don’t ‘run in’.

The top end however does need to seat the rings. Best thing you can do is be very gentle while the engine is cold. ie: wait until the top end is hot to the touch before you start fanging it a bit.

It is a 2 stroke, run a decent 2 stroke oil from the go.

[cowpoos]

Sorry, I am going to call Cow Poos on CowPoos, um, . . . well you know what I mean.

Change the oil & filter? It is a KX, the gear oil is only for the gearbox, clutch & the Right hand main bearing. The crank is sealed off from the gearbox.

The gear oil will have no bearing on the crank save for lubricating the RHS bearing.

However it is a good oil & the gearbox will appreciate it.

The ‘bottom end’ being the crank + LHS main bearing is lubricated by the 2 stroke oil mixed with the petrol. As is the bore.

Bearings don’t need to be run in. In fact it is impossible. Bearings are already machined to the closest specification. Have a look at a ball bearing or a roller bearing & ask how it could possibly be ‘rounder’? Further -bearings work by running on a thin boundary of oil, never touching the metal races they run in. So bearings don’t ‘run in’.

The top end however does need to seat the rings. Best thing you can do is be very gentle while the engine is cold. ie: wait until the top end is hot to the touch before you start fanging it a bit.

It is a 2 stroke, run a decent 2 stroke oil from the go.

\my bad dave....I assumed it was a 4 stroke kx250f ?

[Disciple]

I run Motul 800 Factory Line premix. 100% synthese. That sound like a good oil? Maybe increase the mixture a bit to run it in? And if so I have 600 mls left.. how much would you recommend for 10 liters of AV?

I have always been ignorant to oils and whatnot and have always relied on others opinions.... something I will soon have to deal with now that I am getting serious with my riding.

And thank you so much for the input I really appreciate the help.

[F5 Dave]

That is a good oil. Don't change the mixture ratio to run it in, assume you are running about 40:1 or 50:1.

ie: 10 litres divided by 40 = 250ml. or by 50 = 200ml

One of those graduated mixing tubes bike shops have makes it easy.