Top end tuning question

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GTi_Leo said:
what ratio do you mix redline oil at? I've been looking at amsoil and they claim they can run at 50:1 ratio might be a little to lean for my liking especially since these engines are run at pretty high revs for a long period of time
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If your new to the 2 stroke rc world always stick with 25:1 no matter what brand of oil or recommended ratio. Once your tuning skills are mastered you can run a liener on your oil but I recommend that you don't go over 28:1 to give you a safety net.
 
I'm going with castol 927 next at 30:1 My xt was bought used and it had about 8-12 tanks ran thru it before I got it. I didn't know what I was doing on my 1st gallon of gas and used Lucas part synthetic at 32:1 and now being told castol 927. What you guys think? It ran pretty good now that I have it tuned right. It has a jetpro and racing air filter with lighter hpi wheels.
 
927 is a good choice of oil! If your planning to run fuels like 100LL take note that it has a tendency to separate at certain temps and elevation.
 
I always have high pressure in tank, when gas got high temp, it makes pressure to go higher. so installing one-way valve only solves low pressure issue, not high temp / high pressure. I just made hole large in tank cap.
 
Caster oil is not necessary in these engines and it is the dirtiest oil to run! Its great for break in as long as you get the engine really hot to break down the film strength to allow the rings to scuff into the hopefully plateaued cylinder wall finish. A basic petroleum based oil is good for break in and then run FULL Synthetic. The Caster oil will gum up your piston ring lands causing ring stick and also carbon up the exhaust port. I'm not familiar with the HY motors but I prefer the CY motors because I have measured there cylinder bores and they are very true and have a great hone job on them for ring seating. The best are the head kit motors because the cylinder and head are separate so during machining they are not honing into a blind hole and can get a better finish. The entire top end design is superior then any one peace head design!
 
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