After it dies just premix, the engine will be better off that way anyway. One ounce of 2-stroke oil per gallon, give or take a little.

 

I've been pre-mixing for the past year. The extra peace of mind is totally worth the minor inconvenience.

 

For all those who premix - Does it inhibit performance at all? Does it smoke more? Does it hurt the exhaust or damage something else in the engine? Will it go through inspection ok? And finally, how do you mix it - just dump in the correct amount after filling it up? Sorry if these questions seem stupid, I'm just curious and want to make my new engine last a long time. Thanks.

 

Alright.

1. It doesn't inhibit performance in any way.
2. Depending on the type of oil and pre-mix ratio it shouldn't really smoke it all. Two stroke oils usually burn pretty clean.
3. No, why would it. Pre-mixing is just another way of introducing oil into the combustion chamber except it's not dirty crank-case oil like you inject with the OMP.
4. I dunno.
5. You dump the oil in before you fill up. That way it mixes properly. I always put in 200ml of oil and 25litres of fuel for a 1:125 ratio. Simple. Or as peejay said 1 ounce of oil per gallon of fuel for you yanks.

 

dumb question: what does OMP stand for?

 

OMP = Oil Metering Pump

 

I ordered a new OMP today. $150!!! Yikes! It's worth it though.

 

Worth it? Unless you're made of money, cancel that order! Rebuild it! If it's bad I guarantee it's just the rubber seals. I bought a kit for less than 20 bucks and it was a no-brainer to fix.

 

You could probably find an OMP ona junker in a scrap yard, pull it apart, clean it up and fix it, chances are your saving youself a SHIAT load of money.

cheers'

 

For OMP rebuild info, check out this page:

http://www.mazspeed.com/oilmeteringpump.htm

Then call Mike Lowe of Lowe Performance Automotive at (941) 924-8597 or see the Lowe Performance web site, www.loweperformance.com

Mike will set ya up!

 

Has anyone completely blocked off their OMP, running only premix?

 

Isn't there a risk that the oil would gum up the carb, I mean it doesn't usually flow through the needle & seat, out the jets, etc... it's metered directly into the air flow.

Also, how does it effect the fuel filter.. won't it gum that up too?

 

Keep in mind it is premix oil - engineered to flow through filters and carbs, then cool and lubricate the chamber when it gets there and not have any ill effects on combustion.

 

Yep, I don't see why you would need both unless it's on a highly tuned turbo engine.

 

Ok, stupid question... WHat's the best procedure for checking the OMP?

 

To check the flow, there's a proceedure in the Mazda factory manual. You got one of those right? It involves disconnecting the lines and measuring the output over time at a certain RPM. Just make sure you premix the gas with 2-stroke oil when you do it otherwise you'll starve the engine of oil.

Hope this helps.

 

If your OMP wasn't working properly, how long before you would notice a problem and what symptoms would occur?

 

When I bought my '80 I drove it for 2000 miles and thought it was strange that the engine wasn't using any oil. Checked the OMP output and it was putting out zero oil whatsoever. (Not leaking, either - just no output) For the next 28,000mi the engine ran exclusively on premix. Have no idea how long the PO drove it with the OMP inoperative, but I did notice that the car came with a can of starting fluid in the back I never had a problem with it though...

 

you say you're going to premix 1 oz/gallon, so do you add the oil after you fill the tank or before... you would probably get a better mix if you added before the fill up, but how do you know then how much gas you're going to add?

 

Add it before.

There's nothing to it really... if you have an SA, buy the 8-ounce bottles and fill up when the needle's a little above E, if you have an FB, buy the 16-ounce bottles are run it until the needle's just below E. It's not rocket science to get it exact... usually I'd end up putting 8oz in with 12 gallons. It's still richer than the OMP puts out under most conditions.

 

I had been looking at getting one of these to replace my OMP, then the other day I realised that it goes in between the block and the OMP because I can only see an inlet (for the 2-stroke), am I right? So I guess it's not really worth it, execpt precision, and simplicity.... anyone have one?

 

garfinkle has one on his 94 .he made a tank that sits between the airbox and intercooler. the omp hit the turbo and had to be modified in some way as I remember. he uses amsol 2 cycle oil

 

I just dump a bottle of MMO in my tank at every fill-up...



I wanna add one of those this year. The major advantage to it is that I'd be able to burn MMO (or 2 stroke), and run Sythetic in the engine.

Better for the engine all-around...