Has anyone heard that too much oil blowing by the engine in 4 cycle cars can effect the catalytic converter? I heard on the radio that engine manufacturers are recommending thinner oils because they will eventually have to guarantee the converters for 10 years and this effects it? I know thinner oils help with milage also. But that has kept me from putting too much oil in as a pre mix. It makes sense that the more crap coming off the engine, if not burned completely will effect the converter. My car is stock expect for the DP and I don't want to have to replace the converter. I don't trust the OEM arrangement by itself.

I use the Amsoil saber professional...it exceeds tcw3 according to my amsoil dealer and he called in to make sure it was the best suited for rotaries. Ray wilson at pfsupercars uses the same stuff on customers cars when he tunes them.

Negative. Premix-specific oils are not all the same, just as various motor oils are not the same. Castor-based oils, various synthetic blends, and even petroleum-based premix oils can have varying degrees of dispersion and suspension in gasoline due to their makeup, which means that the premix ratio for effective performance can vary.

In many respects, the Wankel is a two-stroke. Intake and exhaust timing is controlled by port location timing with respect to rotor position, instead of valves/cams. And because there is no oil being splashed onto the housing walls internally, it depends on the intake charge (i.e., intake tract injection or premix) to lubricate the rotor seals...just like a two-stroke. Which is what this thread is all about...

I have never ridden a KX500, I am a 4-stroke guy and ride a YZF450f

If you still have your OMP and its working fine, don't worry about pre-mixing. Some people say it will help the engine run smoother to have some extra pre-mixed oil in the fuel and keep the internals more lubed (with the extra oil coming in via the fuel injectors as well as the oil injectors) but you really don't need it for a regular street driven car if the OMP is working fine.

Assuming the OMP is working, the only time I'd consider using pre-mix on a street car running a cat would be if i were doing a track day where I know I'm going to beat the piss out of the car ALL DAY LONG.

Do a search and educate yourself. There are a lot of good threads out there with info on this subject.

You have to remember the OMP was designed for a stock rotary engine and meters accordingly. A 255 hp engine makes a lot less heat and friction than a 450 hp engine. Heat relaxes apex seal springs and wears down rotor seals, rotor housings, etc.. Adding a little two cycle oil even in an OMP car is not a bad idea, just remember to use less than a non OMP car.

good point, kk....but I've had bad luck with two stroke oils fouling my plugs, perhaps I need to try this saber stuff, although the Idemitsu seems to work fine

well the reason i want to do some premix, is because i have a slight oil leak and someone told me ots a slight posibility its my omp, or lines or something like that but he is coming up to fix it in a week so i figured id premix untill i knew for sure

so how much premix should i use, could i use to much if my omp is working proporly?
also brand and dealer recomendation

thank you all for the info and knowlege

How much less is appropriate? I've been searching and see lots of varying ratios - everything from 100:1 to 800:1. I realize the different oils factor in the ratio, but would you just do something like half the recommended ratio for a non-OMP setup?

Definitely agree with you on that.

Non-omp setup, as in---your car has no omp? That question has already been answered, approx 100:1.

No, I mean with a working OMP, how would you derive an appropriate ratio relative to what is recommended for a non-OMP setup.

I see that Royal Purple recommends 200-800:1 ratio for an OMP setup versus 150-600:1 for non-OMP. So they recommend one-third less oil for a working OMP setup, compared to what they recommend for a setup with no OMP.

What ratio do people use when running in an engine?? I was running 100:1 but went to 200:1 and the engine seems to be building compression better.

Assuming no cat, what's the downside to running too much premix? Aside from throwing money away, that is. Does the excess just blow out the exhaust? Or can this leave deposits or have other ill effects? I read about people fouling plugs with this stuff - that seems like an obvious one.

I've read so many threads on premix that my head hurts. The ratios I'm seeing are all over the map, especially with an OMP. Some people say 4-6oz per tank, others say 16oz per tank, others 100:1, still others 200:1, and I've even seen 320:1 and 450:1. I'm wondering how people arrive at these numbers. Is this trial-and-error or blind guessing?

just wondering where the oil metre pump is and would it if broke prevent the car starting?my rex is wreckin my head ...thanks guys

If only we could talk to the original designers of the 13B-REW...... :us4allswi

Hey, there's only 2 downsides that I can think of to running too much pre-mix:

1) You're adding more oil to be burned, so presumably there will be more ash/deposits left over from burning it. If you get a good clean-burning oil then this shouldn't be a major issue
2) The pre-mix you're putting in displaces gas in the combustion chamber. If you went way overboard and put in 4 oz per gallon you've now displaced a little over 3% of your gas with oil, and the oil certainly doesn't have the same heat carrying capacity, so you've increased your chance to knock a little bit. Also not a huge deal, just don't run a ton of pre-mix and the effect should be negligible.

I keep it simple and so far it's worked well for me (information learned from Damian, who learned it from Foko):

Cars with an OMP:
Normal driving 1 oz per 4 gallons of gas, so about 512:1
Track use 1 oz per 2 gallons of gas, 256:1

Cars without a OMP:
Normal driving 1 oz per 2 gallons of gas, 256:1
Track use 1 oz per 1 gallon of gas, 128:1

Other notes:
1) I always put the pre-mix in before I top off the tank. I think the tumbling effect makes it disperse better in the tank. Alternatively you can shake the car a bit on the way out of the gas station to mix it up.
2) I use Red-Line 2 stroke.
3) For hard core track use I always error on the high side when measuring.
4) I use those graduated water bottles to measure the amount we're putting in. Alternatively you can get a bunch of 4 oz bottles, fill them up and carry them around with you, it's pretty easy to eyeball something that small fairly accurately

I've heard from multiple engine builders over time that the most important thing a owner can do to keep their rotary running well (outside of normal maintenance) over time is to consistently pre-mix. I wouldn't run any car without it.

I think people are worrying way too much about how much to pre-mix. The domain of allowable 2-stroke oil where the the end points are too much pre-mix and not enough is fairly large and there is a lot of room for error in measurement. I just randomly started premixing a few months ago after noticing that my OMP lines were clear. I haven't yet checked if my OMP is working correctly but I pour in about 4-6 oz of 2 stroke oil for every 20 L of gas I put in. I haven't had a problem. This is between 1:120 and 1:180. Give or take within reason and there's nothing to worry about.

info sounds pretty good to me...

only thing id like to add is that too much premix IS bad. i believe it causes you to run lean... i live like 2 miles from the gas station and i got lazy on a 1/4 tank of gas i filled i put in my premix and drove to the gas station... for the first 1/4 mile the cars AFR were insanelyyyy high. then out of no where it cleared up a bit... my theory was the engine injested too much premix which caused the high afr but once it mixed it cleared up... just my opinion...

Good info. I have a working OMP and i've been doing 1/2oz per gallon for about 2 weeks now (2 fuel fillups).

Will turn it down to 1/2 oz per 2 gallons from now on since i mostly drive on the street.

Btw, i use a protein shaker cup for my liquid measurement lol

is it a requirement to get an aftermarket ECU when removing the oil metering pump? because i dont have that kind of money...and i need to run premix (this is for an FC not an FD)

I've heard that there are different ratios depending on the model yr and everything. Is this true? If so I have a 83 gsl but I believe the engine is from a repu not sure of the yr tho

Ok Question!!

2 Stroke pre mix and all is great, however, the OMP doesn't pump 2 stroke oil, it pump 4 stroke lubricating oil. Dont you think the properties are different.

I removed my OMP because I think it was pumping too much and at low idle or speeds it would start to build up and smoke like a freight train. I removed it and that went away.

I used 2 stroke oil with my break in when I changed the factory motor to my turbo charged monster presently. But I was wandering about mixing 4 stroke oil since that is what injected anyway. Also, a really knowledgeable individual that is all over the forum runs this in his car and its immaculant. Every one should know the car, but for privacy sake of something he said to me once, I wont say who it is.

Not saying I dont run premix, I just recently removed the OMP. Just saying about the lubricating properties and what the engine normally burns.