Two-stroke oil pump to pre-mix

[Baldyman]

I have a RMX 250 1993 Jap import. How do i convert it from an oil pump for the 2-stroke to be able to just pre mix the oil/fuel? I think it is running with too much oil as it smokes a bit more than i think it should. Any help would be great - Cheers

[cheese]

empty the tank pre mix your fuel.

Easy!

[dammad1]

empty the tank pre mix your fuel.

Easy!

Yeah thats easy enough, but it would be good if you could take all of it off, i.e the pump assembly, bottle and line etc.

[Baldyman]

When the 2-stoke resevoir is empty, will it not damage the oil pump, but more importantly, will it be sucking air and blowing it where it shouldn't be? Will this affect the running in any way?

[pete376403]

Usuall practice in the past when doing this was to remove the oil pump and make a blanking plate and gasket to cover the hole. Then remove the tank and other bits and mix your fuel/oil. With high quality oil you should be anle to go to 40:1 or better. Don't forget though that every bit of oil you put in is effectively replacing some gas (ie making the fuel air ratio leaner), so it does have a bearing on the jetting. Probably of no importance for road riding, but if racing and the engine is right on the ragged edge, could be the difference between seizing or not.
(this is not something I have experience with but found in an article by Kevin Cameron, a legendary US motorcycle tuner)

[Henk]

I'd stick with the oil pump.
An oil injection system will usually run from about 100:1 at idle to 40:1 at full noise.
When you go to premix you have to go with a ratio that will be right at full noise so you'll be running moreoil at low revs.
I'd look at the state of your air filter and maybe your jetting before you rip the oil pump off.
The only reason to take an oil pump off is to reduce mechanical complexity for one less possible point of failure in a race bike.