MX Simulator

50:1?! I think Suzuki says either 32:1 or 30:1 in their manuals together with Motul 800, which is already a very good fully synthetic oil with a very low flash point. Anything more than 50:1 is absolute lethal to that engine when you're revving it higher than ~6000RPM and you'd want some extra security in case of having an oval and/or concave cylinder or a worn piston.
But I don't think your fuel/oil mixture is the problem, the problem is most likely your carburetor settings. Telling you from our point of view how to set up your carb would be plain stupid, we don't know where you ride, how you ride, the oil you use and about the condition of your engine. When you're jetting a carb, there's not really a secret formula, it's more of a trial and error and going from what the manufacturer recommends in either direction to suit your needs, heck... when done 100% right even the quality of oil is crucial, because the best oils aren't always the best for a particular rider.

zebzone235 wrote:2003 RM250, hopped it up with a Keihin AS-38

Most 250 2 Strokes of that time came with Keihin PWK38 air striker carburetors, so did the RM250s, what carburetor came with it when you bought it, because obviously you went back to the stock carburetor?
I'd try to clean the pipe and repack your silencer(it's most likely soaked with oil), check the powervalve for carbon deposits or unburned oil, run 40:1 Motul 800 or Motorex Cross Power 2T(IMO they offer the best overall package) and eventually pick the right main jet, needle position and dial settings. But again, jetting a carburetor is as personal as buying yourself the right undies.

Yes 32:1 is recommended in the manual but Ive talked to race guys and they start at 50:1 and go from there to see how the bike burns..They've rebuilt countless engines and said you would be amazed how clean the inside is and parts last longer..Not to mention noticeable power difference.

Motoboss wrote:Yes 32:1 is recommended in the manual but Ive talked to race guys and they start at 50:1 and go from there to see how the bike burns..They've rebuilt countless engines and said you would be amazed how clean the inside is and parts last longer..Not to mention noticeable power difference.

i mix 32:1 and my pistons are pretty clean, no deposits on my powervalve or scratching on the cylinder, 50:1 seems like a lot of oil unless your running VP which is great until that stuff sits in your carb overnight and becomes black goop, with all these falling gas prices im a little peaved race gas is still at the same price by me.

model_90 wrote:50:1 seems like a lot of oil

Hehehe dumb dumb

BradyS21 wrote:

model_90 wrote:50:1 seems like a lot of oil

Hehehe dumb dumb

Yeah, 50 parts oil to 1 part fuel, ya freakin' idiot.

To be fair, it is a lot more oil than you would mix into 4 stroke gas.

KTM recommends 60:1 on the newer 250 2 strokes but hey apples to oranges..

50:1, or 50 parts gasoline to 1 part 2-cycle oil is 2.6 ounces of oil per gallon of gasoline. ... Increasing the ratio from the old 32:1 (4 oz. per gallon) to 50:1 (2.6 oz. per gallon)
I use Am-soil Saber
In my buddy's Race bike he uses 60:1 but his engine is built for it....
If your bikes puking oil your using to much oil period unless theirs an engine issue.
You would not believe the difference in power my bike has switching to 50:1

I keep hearing the power difference is huge, but the difference is often smaller than you'd think, because after all it's not as simple as it might seem.
More fuel in the mixture might sound like more power, but you usually increase friction and wear.
To keep it short, more oil = better ring seal = less blow-by = more compression = less friction = cooler running engine = more power.
Of course too much oil isn't good either, I study mechanical engineering next to my job in that industry, but as I mentioned earlier, there's no right or wrong really, however the manufacturer designed and built the engine so their ratio can't be off by that much.
Like I said in most cases people couldn't setup their carburetor correctly, it's not done with changing solely the mixture ratio.
KTM might run 60:1 in the 250SX and 65SX, but that doesn't mean that it would work in a Suzuki or a Honda.
You can basically run any ratio, as long as your carb and engine is setup to match it.

Andy_Hack wrote:Most 250 2 Strokes of that time came with Keihin PWK38 air striker carburetors, so did the RM250s, what carburetor came with it when you bought it, because obviously you went back to the stock carburetor?

From what i could find online and when reading the manual they came with the Keihin Air striker AG Short Body which has a powerjet soleniod as well as a throttle position sensor. I switched it out for the screw top version of the air striker.

Sorry to make a double post like this but what i meant with getting rid of unburnt oil is what kind of cleaning solution i should use on the plastics ro get right of all the black goo. The carburetor is already dialed

Good advice guys are leaving in here. I forget if I ran 36:1 or 40:1 in my RM250 only have a little oil getting on my plastics. Ran a lot of the oil out there besides the higher end full synthetics like motul 800 and belray h1r. Back in the day they used a lot more oil since it was not as good as the full synthetic stuff we got today. Castor 927 is a really good oil it will eventually leave deposits in the engine small price for the castor smell I guess.

Always ran 32:1 on 125's then 250 to 500 40:1 is much better.

As far as removing the oil from the plastics not really sure my rear fender is white on my 125 so its stained forever now haha.

With KTM saying 60:1 I would only do that with the oil the manual recommends motorex I believe? I tend to go with the bike manual and the oil manufacturers oil mixing ratios.

On The Pipe wrote:Good advice guys are leaving in here. I forget if I ran 36:1 or 40:1 in my RM250 only have a little oil getting on my plastics. Ran a lot of the oil out there besides the higher end full synthetics like motul 800 and belray h1r. Back in the day they used a lot more oil since it was not as good as the full synthetic stuff we got today. Castor 927 is a really good oil it will eventually leave deposits in the engine small price for the castor smell I guess.

Always ran 32:1 on 125's then 250 to 500 40:1 is much better.

As far as removing the oil from the plastics not really sure my rear fender is white on my 125 so its stained forever now haha.

With KTM saying 60:1 I would only do that with the oil the manual recommends motorex I believe? I tend to go with the bike manual and the oil manufacturers oil mixing ratios.

ran 927 in my 150sx for past 4 years, cleanest oil ive used, motor looks brand new when stripped down, piston is immaculate everytime

Let's see if I remember how to embed a pic. If the embed fails, link: https://i.imgur.com/rLh52FN.jpg

[img]rLh52FN.jpg[/img]

Sorry If you see this in two threads




VERY happy with how these graphics turned out. The more I ride this bike the crazier the difference seems coming off of an 02 kx125. Hoping to either coat the hubs green or buy an edge wheel set from dubya this summer, but isn't currently a priority.