My son has a 07 kawasaki kx85.I am putting a 92cc big bore kit in it.I have been using Motul 800 pre mix.I wanted to change to Castrol 747.Why?Castrol 747 is a blend of synthic and caster.It is in the owner manual that it will not gum up the power valve.I would like to use the bean oil,it bring back memories with the smell.What would Yall use.Thank you.Mark
castrol 747 vs motul 800
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Never used A747, as twenty years ago we used R30 in karts as it supposedly gave slightly more power than the semi-synthetic A747 and the head was frequently lifted for inspection anyway, so carbon build up could be controlled.
I think you will get more deposits with A747 than the 800 2T which is a mix of esters (not castor). I've seen reports claiming that A747 is roughly 30% castor (admittedly off the 'net, so take it for what it's worth).
If you think you'll be pulling the head fairly frequently it wouldn't be a problem, but if it is going to hopefully be together for a while, I'd be thinking 800 2T or Silkolene Pro 2 SX
FWIW, the local KTM factory team use Motul 800 2T @ 40:1.
Most kart racers here now use elf HTX 909 which is heavily castor based and good for 25,000RPM, whereas the elf MX oil is HTX 976, a full synthetic (good for 18,000 RPM) is claimed by elf to be cleaner burning than the HTX 909.
I think you will get more deposits with A747 than the 800 2T which is a mix of esters (not castor). I've seen reports claiming that A747 is roughly 30% castor (admittedly off the 'net, so take it for what it's worth).
If you think you'll be pulling the head fairly frequently it wouldn't be a problem, but if it is going to hopefully be together for a while, I'd be thinking 800 2T or Silkolene Pro 2 SX
FWIW, the local KTM factory team use Motul 800 2T @ 40:1.
Most kart racers here now use elf HTX 909 which is heavily castor based and good for 25,000RPM, whereas the elf MX oil is HTX 976, a full synthetic (good for 18,000 RPM) is claimed by elf to be cleaner burning than the HTX 909.
I thought the move away from castor was because it gummed up the power valve? maybe that's old school castor oils.
The best thing can do keep power valve clean is Leaded race fuel, even mixed at small amounts the lead has a sand blasting effect on carbon.
when i raced an oilmixer for 2 years, i ran Yamalube 2R and VP C12 (its leaded). never had an issue with the powervalve nor spooge.
at home i run the Amsoil in my weedwacker. i don't even measure the ratio. just pour it in, fuel is red, start her up. i took it apart last year and everything was clean inside.
2 different products, 2 good experiences.
at home i run the Amsoil in my weedwacker. i don't even measure the ratio. just pour it in, fuel is red, start her up. i took it apart last year and everything was clean inside.
2 different products, 2 good experiences.
I made the mistake in the late '60s of running a heavily modified ported two stroke twin on Castrol R as a premix. The R produces a very hard carbon that eventually restricted the baffles in the muffler and I melted both pistons. It took an oxy acetylene torch to even get the baffles out of the muffler to clean them up!
So my concern would be with the hardness of the carbon produced, rather than the amount, and the neccessity (IMO) of cleaning off that very hard carbon from every downstream place, not just the powervalve...
But, Oh! that smell...
So my concern would be with the hardness of the carbon produced, rather than the amount, and the neccessity (IMO) of cleaning off that very hard carbon from every downstream place, not just the powervalve...
But, Oh! that smell...
yeah oil couldn't have changed in 38+ years.
It is my belief that Castrol R is intended as a racing oil, suitable for engines that get torn down frequently, and that it is the castor oil itself which produces the very hard carbon deposits. This doesn't make it unsuitable for racing engines, or maybe even for anything other than pre-mix two stroke engines. which burn a lot of oil, compared to anything else.
So no, I don't think that that particular property of castor oil will have changed much in 38+ years, or will change in the next 38,000 years.
I was foolish to use it as a premix oil in a street bike, and on the basis of my mistake, I offer a suggestion for something to watch out for so someone can avoid a problem they might not otherwise expect.
So no, I don't think that that particular property of castor oil will have changed much in 38+ years, or will change in the next 38,000 years.
I was foolish to use it as a premix oil in a street bike, and on the basis of my mistake, I offer a suggestion for something to watch out for so someone can avoid a problem they might not otherwise expect.
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