20:1 Castro high test gas

Switched my '84 husqvarna 250wr to 20:1 castrol mix with high test gas. Seems to run but needs to be richer on the pilot. I'm running 45 pilot and 430 main the needle in the middle groove. She runs so much better.

I picked up a hand held tach to set the balance screw. I can't hear the rpm smooth out.

I set two strokes to intentionally not idle, setting the slide open enough for it to idle can/will cause seizures on closed throttle deceleration.

The slide shouldn't be open much if it's jetted right. I'm just going to richen it, check it and run it.

I've always been told the same by my old man. He says they don't carburate properly if the slide never fully shuts either.

20:1 also seems a bit lean on fuel. I run all my old huskies on 40:1 97 octane pump fuel with caster based oil.

caster based 40:1 has always worked well for me. no need for 20:1

There is no need to ever drop bellow 24:1 as this ratio is dyno proven to create the best compression ratio and is plenty of oil. Plus it is extremely hard to jet at this ratio, most people don't ever drop below 32:1 simply because of jetting. On a side note, the leaning of fuel by addition of a higher ratio of oil is overly stated as the difference between 24:1 and 50:1 is only 1.9% less actual fuel. (good campfire bet info, will make you some extra cash)

tinken, whats your opinion on castor? i know using a heavy castor oil that is for racing only like klotz benol is dirty but i run the super techniplate, which is "synthetic" and blended with 20% castor. seems to burn pretty cleanly for me in several bikes over several hundred hours. castor is fascinating, and i know you are keen on oils...i know a full synthetic will likely protect everything great

There really is no reason to go below 32:1 with today's oils and the added convenience of 32:1 is it is super easy to mix because you just put 4oz per gallon.

Ty and I love castor, in fact we purchase some of our materials from the same company which supplies Maxxima with their castor for their 927 product. It smells good, and in an environment like at the track, with so much alcohol being burned, it's a nice addition. Yes, 32:1 is what most of the current desert off road guys run who hold their bikes wide open for extended times, it saves them.

32:1 or 40:1 it doesn't really matter as long as you are happy with the results. I race Motocross here in the UK at sea level and don't ever go above about 25 Deg C and 40:1 works for me in my 83 CR 500.

It's also handy that 40:1 is 25 milli litres per litre for us in Metric land...

Sounds good to me!

I've been running 50:1 Maxim for the last 10 years or so with no problems. My original 1978 390-OR still has the original piston and hooks up like a monster off the line! Also still has the original clutch using auto transmission fluid. Love that bike.

one small energy drink can of oil to 10 litres gas is prefect for a days riding at 40;1 lol

64:1 for me but , I ride slow mountain single track. 2 oz's per gallon is also easy to remember when mixing. Torco GP7 with it's low flash point keeps everything clean.