250-500cc 2T oil

Hey guys, sorry if the question is too stupid.. but does ratio of gas to oil affects jetting? let's say bike is tuned to run on 40:1 and than one would change it to 50:1.. does jetting needs to change?

I used Bel Ray H1r in the past. Never had any issues but have noticed it separates when left sitting over time. The Amsoil Interceptor is so much cheaper and mixes way better. IMHO I ran Klotz for a little while bought a bike and it came with a gallon of it. Noticed sticky power valves with it at 50:1

This in a KTM XC 65..... 40:1 tho

We ran Amsoil, Bel Ray H1R and Klotz all at 50:1 in KX 100 ring a ding ding out is the desert wot a lot with no issues.

Castor is bean oil, from the castor bean. It's a natural ester, that's refined to remove gummy parts. It's the target basis for just about all synthetic 2 stroke oils due to it's incredible film strength. The best synthetics will use a man made ester, which is basically a synthetic castor bean oil, but without the gummy part.

Back in the '90's I was building a lot of race engines and I would get a lot of 2 stroke oil companies trying to get me to recommend their oil to my customers. One common thing I found was that most recommended adding 20% castor to there oil for extreme conditions. That would be engines that spend most of there time wide open.

Castor has also long been added to 4 stroke road racing engines, as a top lube, in high mixture ratios. Yes, it's that good.

The biggest problem with a castor, or even some synthetic esters, is they have a pretty high flash point. That means most of use trail rider types experience gumming and spooge, because our motors tend to run cooler combustion chamber temps. Top MX or road race motors are pushing the 1200 degree mark all the time, while most of use probable spend most of our time between 800 to 1000 degrees.

Fact is, most of our engines are set up in a high enough state of tune to even get to 1200 degrees, even jetted lean. We don't have enough compression, squish velocity, timing advance or volumetric efficiency to get there, let alone the fact that we hardly get past half throttle most of the time.

Thanks. Castor is great stuff for motors that can burn it. They'll look great when you pull them down, but you can't wait for 300 hours to do it. Wear protection wise I don't think you can beat it.

Thanks Motorhead that's some really insightful stuff. So doing an event like a beach race when you spend extended time at full throttle would it be wise to add some Caster to the mix. Would it be added as part of your mix ratio or in addition.

If you're using a good oil now I wouldn't bother. 20+ years ago they were still working on molecules that were as good as castor. I think the stuff we have today is probable there. Most of the top oil companies have some really great synthetic esters out now.

I've been using Klotz super techniplate for some time for that reason. It's a synthetic that has 20% castor blended in. I'm sure there's something as good or better, ( actually, Klotz claims their R50 is better ) but I'm just kind of hung on it.

One word of caution, some oils won't mix with castor. Be sure to check into that if you are thinking about trying.

so i re read this thread 3 times..and still confused..you guys are fast and push your engines hard,

but
for slow woods riding on new to me 09 WR300 ..will amsoil be best? Dominator or interceptor?

I race the ECEA series in B class on my 12 WR300 and run Klotz with great results. Ive been using it for 60+ hours on the original top end. Gonna crack it open this winter and re-ring it just to be on the safe side. I might be wasting my time and money doing so but its good preventative maintenance and piece of mind.

i have had good results with klotz techniplate as well...love the smell! i dont race at all, but my top ends have held up great

Adding to much 2 stroke oil to your gasoline mix can actually create more or excessive friction/heat and it also reduces the octane rating of any gasoline due to dilution. Nothing ester based or synthetic can ever replace the film characteristics on non friction or friction surfaces of the internal structure of any 2 stroke engine which keeps down corrosion better than any oils nowadays. I'm not saying to not run synthetics by any means but I used to buy "Blendzall" by the cases and the internals of iron liners on my old 2 strokes would last a good long time with the old castor based oils, so did the crank bearings. Even to this day I don't think anything smells as good on a 2smoker.

Dominator has a slightly higher flash point from what I've been told so it is a little more spooge prone.

Dominator's flash point is slightly higher and extra/more additives. The extra additives are why it's recommended for engines that receive occasional tear down due to the possibility of deposits. The amsoil rep told me either one would do the job for mx but dominator was best suited to high rpm, max effort race engines. For woods I would use interceptor.

I've read many times that Dominator does not have the anti-corrosive additives of Interceptor. But I do know people who use it casually ridden bikes no problems as far as excessive spooge or fouling or anything like that.