Changing auto lube ratio - TM250

[Jumbo J]

I'm running different oil now which should be mixed 36:1. std setting on the autolube is 20:1. Is there any way of knowing what the oil mix ratio is when making the adjustments at the pump. should i just back it right off to its min mix setting on the adjuster?

[Tim754]

Jumbo, where did you get the (erroneous?)  info that the TM's auto-lube is set at 20/1?  It is not in any way metering or measuring the flow of petrol other than the pull on the throttle cable. Remember the Suzuki is from the early to mid seventies and is not fitted with any computer controlled technology pus.
 Put your new brand of oil in the tank, ride and have fun.  Cheers Tim754

[Jumbo J]

Jumbo, where did you get the (erroneous?)  info that the TM's auto-lube is set at 20/1?  It is not in any way metering or measuring the flow of petrol other than the pull on the throttle cable. Remember the Suzuki is from the early to mid seventies and is not fitted with any computer controlled technology pus.
 Put your new brand of oil in the tank, ride and have fun.  Cheers Tim754

woops was a hastily prepared question, i should have also asked is it actually set to 20:1 instead of assuming what i had read on a pre mix tank. but thanks for clarifying that Tim. Can i rephrase the question then. Under what circumstances would i consider backing off the oil to fuel mix ratio, given that (and i am assuming again) that modern oils can run a lot leaner than they could 20 yrs ago. 

[Tim754]

Would not recommended changing from where its working now fine to fiddle about with premix ratios (till ya ....oops...) cheers

[pokey]

it depends on which school you went to as what is correct lube for a 2t

. i didnt go to school i wagged and played with my old suzukis.

I am of the belief that you dont run modern synth oils in an ols air cooled bike. reason is tolerances on moderns match the modern oils. old engines like mineral oils .
Im also of the belief that the more oil the cooler your engine runs as it has a wicking effect to drag heat away .

Other guys may and probably wil disagree but keep it well oiled and it will run good.
it will blow smoke but it wont foul a plug if your ignition is working properly.
. I have my pumps set at 3/4s open on my 185s and dont run the split cable.

[Jumbo J]

Pokey, the oil i'm using is a mineral based castor not synthetic. does smoke a lot, havn't done a plug chop yet but will do this weekend at the track. like the idea of not running a split cable though. how do you lock the pump in a set position?
JJ

[pokey]

use the end off an old cable and tie a knot in it  is the easiest way, the knot sits in the adjuster out of the way and just wind it up to 3/4 open.
 castor is good for pommie bikes but it will give you a lot of grime in your engine and a bit more carbon in your pipe.

i have run my bikes with different pump flows and they have always ran better and cooler with more oil. even with the pump on full they still perform  good just cooler. Its the smoke  and unburnt oil that gets me to back it off to 3/4.
 do your own tests on what level works for you and dont be shy about  giving it more oil.

[BultacoMacca]

Doesn't the oil pump supply oil to the main bearings in TM motors?

[djr]

Doesn't the oil pump supply oil to the main bearings in TM motors?

If the TM autolube set-up  is the same as RL250/TS250 from that era then I think left hand main is fed by oil pump
and right hand side is lubricated by gearbox oil, also think there may be an oil feed to inlet manifold ?

[brent j]

The Suzuki CCI oil injection system pumps a fixed amount of oil to the left hand main bearing which is then fed to the big end. It also pumps a variable amount of oil to the inlet tract which is controlled by the second throttle cable.

If you want to remove the oil injection system completely you need to split the cases and do a few mods.
My TS90MX is set up from the factory to run pre-mix but still has the CCI system fitted. They disconnect the oil pump cable and leave the lever in the idle position. This keeps the oil feed to the main LHS bearing and big end and a constant but minimal feed to the inlet tract. You need to run an oil tank (Suzuki supply a small one for this purpose) then you run pre-mix at what ever ratio you need.

I believe the Suzuki system to be very good at providing lubrication to the main bearing and big end.

[oldfart]

Exactly what Brent has said is correct ..... and this is why the cranks don't fail on these old girls.

[Lozza]

Run castor/synthetic oil and get superior lubrication. There are 125cc engines that pump out twice the HP of a TM 250 and don't need a oil pump.
Converted my TS400 yonks ago, no bearing issues

[Jumbo J]

thanks for the tip Lozza, good to know im on the right track with the oil. might eventually get around to flicking the pump when the motor is eventually split. i kinda liking the convenience of not needing to premix it.   i wanna get some more ponies and don't want to modify my original barrel. should i look for a TS or TM barrel to have the porting done?