no omp rod what would happen?

no oil pressure?

what are the advantages to running pre mix
and dis advantages?

 

a new motor with no omp then you need to premix or you will blow your motor up

 

Pros:

1. smoother engine operation
2. longer engine life
3. extra protection for your engine (if you're still running stock omp)

Cons:

1. People stare at you when you get gas
2. you have to carry 2-cycle oil cans at all times
3. Extra cost of 2-cycle oil ($1.29/16 oz/fillup at wally mart)

For me there's no doubt--premix is the way to go. The naysayers are wrong on this.

 

FC3S - Nataku - thats neither a pro nor a con


this has been discussed very extensively - a search should turn up a tonne of info

the basics are that premix burns off the rotors and surfaces more effeciently than motor oil does and premix provides more direct protection at highrpm


the pros are more efficent lube and less residue

cons are mostly emmissions related and the fact that you need to keep topping off your 2 stroke oil every xxxxkms

 

Mazda's name for it is the "metering oil pump" or MOP.
It dispenses oil by volume at near zero pressure.

Those with S4's can block it off & pre-mix at will.
The S5 guys have to deal with the electronic MOP feed-back issue or the ECU will go to default "limp home" mode.

 

If the rod is disconnected, little if ANY oil will go to the oil injectors. Little or none is more accurate.

The motor won't go kabang/blow up/ disintegrate if it gets no oil thru the oil injectors. It WILL wear out much faster as far as the apex seals go. It will NOT cause rotor bearings or any other bearing to go kaput. It will be several thousand miles before the engine is destroyed. Make that in the ten thousand miles range of destruction. Eventually the apex seals will wear down and *roll over* and destroy the rotor housing/housings/rotor.

The rod determines how much oil is injected. Full up....lots of oil. Full down.....no oil.

 

could you just disconnect the rod and pre-mix?
or is a block off plate needed?

also what is the ratio used?
how much 2 cycle premix with each gallon?

 

I usualy used 100:1 Easy number and safe bet but check the other thread about this really indepth

 

1 oz./gal = 128:1, which is not 100:1, works fine and is more than enough. If the rod is removed, and the mop is untouched, the spring in the mop defaults to a middle position and still injects oil.

When I bought my 1st 7, I found this rod that was not connected, and did not know what it was, later I found it to be the mop rod. I have no idea how long the po had it disconnected, but I have put 30k on the engine with no issues. I did hook it up within the first week of owning the car.

 

I've had four OMP totally apart in the last month and, sorry to say, none is spring loaded to a middle positon. That's three series four and one 1st generation.

Everyone is spring loaded to a stop for the lever. I don't know what generation you've been looking at, but it does not seem to be first gen or series four.

On page four of this thread https://www.rx7club.com/forum/showth...&highlight=omp I jpg'd several pictures of the internals of the OMP.

 

still wondering if i
could you just disconnect the rod and pre-mix?
or is a block off plate needed?

 

DING DING

 

I'd suggest checking this out before removing a perfectly working OMP/MOP:
http://members.ij.net/mrmazda/cfaqtext.html#MIXOIL

Race cars have different requirements than our street cars:

1. Idle time is low;
2. Idle quality doesn't matter;
3. Reliability matters a lot;
4. Combustion chamber deposits matter little, as race engines get rebuilt frequently;
5. The engine is operated at or near peak load most of the time.

Mixing oil in the fuel provides an adequate match between oil needed and oil supplied under such conditions. And, one more potential system failure can be avoided, besides a little weight saved.