It seems most agree that adding Pre-Mix is the way to go. What can't be agreed on is how much to put in. I don't want to overdue it and leave a smoke trail like a Jet Plane so I only put in 8oz at a time.

Chuck

 

I use 13 oz at a time, my OMP is still in place and working properly, and NO smoke is visible from my tailpipes.

 

Don't get the wrong idea! I use synthetic two-stroke oil in my modified OMP system. Not anything like regular synthetic engine oil. This is the same kind of oil that I used for years in my two-stroke motorcycles. Also, as far as owners being too lazy to premix, I don't agree. An OMP (with the proper oil) is designed to do just what it says, METER the oil into the engine based on need and speed. Premixing uses a "one size fits all" mentality. That's why OMPs started showing up on motorcycles. One last thing.....When I switched to a synthetic injection oil on my motorcycle, I cut the injection pump setting in half as directed. No more smoke, never a problem.
I had a small engine repair shop for years. If you think that pre-mixing is the total answer, go to a small engine shop and ask them about carbon buildup in the exhaust ports on two-stroke engines. It still happens.
You just have to do what you think is best and hope it works for you. Like I said before...If my engine makes it to 150K with no major problems, I will consider my OMP setup a success.

 

I disagree that the pre-mix option is a one size fits all answer. The two stroke is mixed into the gas but as engine speed increases so does the supply of fuel so more two stroke gets added aswell. If I am wrong then I need it to be explained cuz that is how I understand it.

 

As speed increases, you're right, so does the fuel. However, if you have 75:1 pre-mixed you're just feeding more 75:1. On the old bikes, the pump increased flow with the throttle cable AND spun faster with the engine speed. That resulted in an increased oil mixture.
I won't lie, I'm not sure the OMP on the 7s works the same way. I'm sticking with my injectors until I tear my own down. If I've been wrong, I'll admit it openly then and start dumping oil in my gas tank.
I like the idea of using two-stroke oil over crankcase oil because it is blended to burn cleaner. I think that the type of oil that makes it to the combustion chamber is what makes the difference, not how it gets there. I think that there is enough turbulence in the combustion chamber to distribute the oil well enough.

REMEMBER....That's just one old man's opinion. The ticker on the 7 is nearing 95K and she'll still idle at 650 smoothly with no smoke out the pipes. Of course I also believe that the lack of cold-weather starts here in the desert is helping.

 

How would one go about making one of these block off plates?

how long of a job is it to remove the OMP, injectors and vaccum lines? Especailly if your a amatuer rotory guy.

 

Just a quick Q? I just love the smell of castor oil in model airplanes. Would you be able to use castor oil as a premix? or would it not mix or lubricate?

With model airplace its mixed with nitro and other alcohol I think. So it might not work? Just thought i'd ask...

 

wouldnt it be less economical that way? price wise i mean?

 

To most people yes, but to the one who love there cars enough, no.

 

It depends on what you mean. I personally had a boost in MPG when I pre-mixed and the car idled smoother the more I added. The boost in MPG out weighed the cost of my two stroke so it actually saved me money to pre-mix as it cost less to buy the pre-mix oil than pump the extra gas. It would be magnified now with higher gasoline prices.

 

I don't believe that it would be a good idea. Aside from not knowing how effective a lubricant castor oil is (speaking only for myself here,) I would wonder if it would burn away cleanly as premix oil does...

What kind of shape is one of these model engines in after using castor oil? Full of goop? Spotless?

You'll be taking a gamble with a motor that will be a PITA to replace if the attempt goes awry...

 

it turns to goop if it sits... i would not do this.
funny story. don't know if its true but my air frame power plant teacher told the class that back when there was no air force and the army had plains with the radial engine they used caster oil to lube the engines and they had no exhaust manifold you ann the exhaust would be blown in there face, the pilots would get sick and would get the runs. how that would happen from breathing it i don't know but he continued on to say a pilot landed needing a pit stop and left the plain running it started to take off down the field he landed in and crash in to a barn, the pilot got caught.

any way it was funny when he told it.
slow87... you know who told that one

 

Yeah I would onlyl use TCW-3 oil nothing that isn't certified with that.

 

LMAO!!! funny! but seriously! does puting premix oil in gas clog Fuel filter?

 

nope. I ran pre-mix for 10k miles and I only change my filter because it was the second used on the car and the car has 158k miiles at the time

 

Also i read back many threads ago and notices that if oil injectors go bad your motor can blow! well how can i check to see if my oil injectors are working and is there a place that i have to add oil besides the engine its self?

 

If your going to pre-mix you obviously need to use pre-mix in the tank. If you want to test your oil injectors you need to remove them and do the FSM test procedure. Sometimes engines are running on 1 or 2 oil injectors and they start to go to ****. So yeah check those bitches.

 

fsm check! ok im goma look more into that!

 

Yeah definately

 

i premix a little bit just as a safety precaution. about a 200:1 ratio -alex

 

so you guys just remove the oil injectors....fabricate some block off plates...then fill up your tank and put a single bottle of some pre-mix oil and thats it?

 

10-16 ounces its half of a quart. Yep thats it.

 

10-16 ounces its half of a quart. Yep thats it.

 

Why oh why can't this thread just die!

 

i wont let it? :p j/k...let it die