2 stroke mixture 1990 RM250

[Scotty99983]

Hey everyone, got a little bit of a family dispute over this issue.

my clymer workshop manual for my 1990 RM250 says the mixture should be 20:1, i am running it on that mix or just slightly more 2 stroke oil. ill admit its a little bit on the smokey side and the plug shows it being oily.

my bro is sayin that it should have less 2 stroke oil in it more like a 32:1 mixture but i am totally unsure as to what is best. in my opinion if the manual tells you one thing then it must be right since its a workshop manual. but i would like a few more people on my side but please tell me what you guys think.

thanks

 

[slickpuss]

Your likely to foul some plugs at 20:1. I had a 91 RM and a 93 RMX and both of them were very happy to run in between 32:1 to 40:1 depending on the temps outside. Even at 32:1 plugs would get fouled at times.

 

[SamStafford]

I have a 2000 Suzuki RM250 and I use 32:1(4oz of 2-stoke oil to 1 gal. of gas). Never had any problems...yet.

 

[2strokerfun]

you'll get a hundred different answers. Just do a search and read for a week. But if engine is within specs and jetted properly, 20:1 is fine and won't foul plugs. My bike is supposed to run 20:1 according to manufacturer, but I run it at 28:1 and it is jetted properly for this mixture. A lot of people think 32:1 with modern oils is a good compromise and I think this is a true statement. But changing from 20:1 to 32:1 is not going to change a thing on your plug. Sounds like you might need to rejet a bit , your top end may be getting a little worn or your right side crank seal leaking a bit. But either way, pick a ratio and stick with it. That way, you can jet your carb accordingly and have one less variable to worry about.

 

[Scotty99983]

well ive stuck to 20:1 and the bike is running fine no bogging down or that and it aint fouling plugs

 

[2strokerfun]

Then stick by your guns. I like more oil. If you stay consistent, it is one less variable to worry about if you have to start troubleshooting a problem.

 

[whenfoxforks-ruled]

20:1

 

[Chili]

Pick a ratio, jet the bike accordingly and enjoy. There is no right or wrong answer between 20:1 and 32:1.

 

[whenfoxforks-ruled]

18:1~32:1, for an MX engine? Farm equipment, weed eaters and boats are different applications.

 

[SamStafford]

20:1? How many oz is this to one gal. of gas?

 

[Scotty99983]

well its 250ml of oil to 5 litres of gas, im not sure how many oz that would be

 

[GoldDrum]

20:1? How many oz is this to one gal. of gas?

The best investment would be a measuring cup. They sell them cheap at the dealer. It has all the ratios on the side of it.

http://www.rockymountainatvmc.com/p...3&keyword=OIL+MEASURING+CUP&prodFamilyId=3568