Premix dilemma... again!
 

Hi! I searched the forums under "premix" but since I suck at searching internet forums, I have had little luck with info.

I read that a lot of people premix even with the OMP on, and a lot take it off, because they dont feel safe to trust the factory OMP system. I also heard that, it's not as bad as some people say. Most of the OMP systems apparently get removed because they have not been touched since the factory, and are in poor operating condition, or already broken. Then, the mechanical S4 oil metereing system has been known to be more reliable and work better than the finnicky S5 electric OMP. So, my theory on this whole thing from the info that I HAVE gathered is that, if you have an S4 OMP system, rebuild your omp and lines, and use good quality fuel, then you should be fine for the most part, with an engine that's close to stock with reliability and simplicity modifications.

Anyway, so I found an FC I want to purchase, and the car IS an S4, but it had its OMP removed due to lack of trust from the owner. I now face two options: one, is to, (im my eyes) look realy ghetto and have to explain why the hell I'm putting two stroke into my gas tank at the fill up station. At least we don't have attandants here in the US like they do in Japan and some other countries!

As for the second option, I can source out a used OMP system, and then rebuild it and reinstall. However, at this point, this almost seems like too much effort for what it's worth, since I think the reinstall will need too much stuff to be taken apart in order to slap in back in there, and I will still put at least SOME oil in the tank just to be safe anyway.

Also, I have two 8oz bottles of Penzoil "2 stroke oil" but it says for air cooled engines. I got em back when I was trying to rebuild this moped, but i couldnt get some parts for it, and it never got done. I wanted to use these on my first couple of fill ups, so does the "air cooled" part matter there? And what would be a good ratio for a street ported T2 with 10psi of boost and 680 secondaries?
Would about 4oz for 10 gallons be enough of too little if it was a daily and an auto x car on the weekends sometimes?

any TCW3 premix oil will do. safe ratio is 1 oz per gallon of gas

iv always been premix, i feel like the car runs smoother. can care less what ppl say as im at the gas station, and fouling plugs aren't much of a problem anymore :)1-100 ratio wont make your car smoke either (mine doesn't)

I've never had this problem.
If anything, people get curious as ask what you are doing.


-Ted

Likewise I think I have only had like 2 people say anything to me and I have been doing it for over 6 months

1oz per gallon of gas

I don't know why you'd feel the need to have to justify what you do to your own car. if someone asks just tell them you're adding super JDM "power juice" and leave it at that :)
most people wont even notice as they have their heads inserted way too far up their own butts to notice anything going on around them

If that really is your big issue there are ways around it.
I've seen a couple of threads where people have installed aux. tanks for the premix and pumped it into the gas tank electrically from inside the car.

Lacks the ease ( remember, what you call "ghetto" some might consider "elegant simplicity") of just pouring the oil in manually but would eliminate the embarrassment of explaining what you're doing... not that I can imagine anyone giving a crap.

A third option you might consider ( and IMO possibly the best of all) would be to reinstall the OMP, modified to inject two stroke premix instead of engine oil.

If you are looking for opinions, I say to reinstall the metering oil pump, clean the nozzles and install a new set of lines.

I agree, premix is a royal pain in the ass. It cheapens the whole car in a way that I guess only a certain percentage of people feel. I've been premixing these last few months because I'm too lazy to replace my lines at the moment (I would prefer to drive the car after it sitting in my garage for 5 years, not tear it apart to fix it while the weather is still good) and I loathe going through the motions at the gas pump. I always manage to spill some on my hands and the car, it takes an extra few minutes, costs more for the oil (and it means that I have to keep a jug of 2 stroke in the car at all times) and makes people talk to me about it...

Buy the pint sized bottles.

Put one in and pitch the empty at fill up. No jug needed.

I buy a 16oz bottle. I have afunnel I use no mess EVER none on my hands non on the car nothing.. takes me an extra 2 minutes MAX... pour it in hit the nozzle clean up while the gas is filling and pull the nozzel drive off..

If you cant spend an extra 2 minutes to fill the car up then you obviously have a way more important life to have car to toy around in..

btw I pay 1.37 for a 16oz bottle... I rarly fill up so 1 bottle lasts me atleast 2 weeks.. (I get 19mpg in my 86 n/a)

some people act like the S4 OMP is indestructible. half the S4 RX7s ive owned have had bad OMPs or barely working. when you redo the lines you might as well rebuild the OMP too, its cheap and sometimes they are the culprit. its not hard to put them back on, its just a few bolts, and take off the upper intake and screw in the injectors. as for premixing, its a pain but its surely not ghetto, rotary engines need oil, thats all people need to know. better than sitting on the side of the highway looking ghetto cause your OMP stopped working and your engine blew. :)

i will be premixing soon, sounds like ima be having fun :)

This is very expensive and wasteful. One of these bottles costs $2.99, while the big jug of 4L costs $9.99. Also most gas stations don't have a recycling box for the plastic. There's a bit of irony in that statement I know, but it makes me feel guilty to throw it out.

I have never, ever seen a bad S4 or earlier metering oil pump. It just can't fail unless it sustains massive physical damage. The o-rings can leak, but that does not stop the pump from working.

Sounds like you have a better system then I. I keep a small measuring bottle with cap in the car and have it prefilled ready to be added next time the car is gassed up. However it's inevitable that there is spillage, and even one tiny drop of oil on the outside of this bottle means that the hands get covered...

What I should do is hunt around my garage for an empty brake fluid container, which happens to have a long spout and is about 16 ounces. Or I could just spend 30 minutes and replace the metering oil lines and adjust the pump. :)

You said it, not me. :)

Bridgeport, GT40R, etc....Doesn't make for great mileage in the city. It's unpleasant enough buying gas, let alone having to mix 2 stroke oil into it at the same time.

I run Protek R in my FB, which has no OMP. Every fill up is just about 12 gallons, so last time I went to Pettit racing I got some empty 12oz. bottles and a gallon of the oil. I just fill up the bottles at home and keep one in my car for when I get gas. It takes me no more than 15 seconds to put the oil in, then I fill the tank.

what I have is a funnel with a tube on the ned.. the tube goes into the tank and the funnel has a valve on the bottom.. I look at the side of my 16oz bottle and then pour in the amount of oz I tend to put in gas..

I know if I am putting in 10.00 I need 3 oz.. I pour in my 3oz, turn the valve off ptu the cap on the hose. put the cap on the bottle toss it into the trunk and then stick the fuel nozzle in the car..

as for the time. I mean seriously it is an extra 2 minutes.. I know I can spare that at the pump hell I spend more then 2 minutes a day just looking at my car...

and I was only saying at 1.37 (for me) for a 16oz bottle it is a little cost to know that u have got security...


btw I have to agree with aaron.. I have NEVER seen a S4 omp fail EVER!!!

noper. it definitely can. i recently replaced the lines on my GTU and the OMP was not working, i knew i did it all right so i replaced all the o-rings in the OMP and it worked perfect after that. IT CAN and it DOES happen. even more regularly the air lines come off the injectors, then what? what if dirt clogs the injector? your injecting is then compromised a bit. where as premix wont fail unless your fuel system fails.

its endlessly debatable :argue:, theres pluses to each way. im sure that OMP lasted for 130k miles and might last another 130k but im not sure im willing to take that chance.

Dont get me wrong I still say premix>omp and always will

i dont see whats so hard about premixing.. on my n/a, I just used the standard 32oz bottles, they pour right in no problems. you dont need a funnel, no measuring.. just use about a third bottle per fillup and youre set. takes all of 15 seconds

Wow, I just realized I over pay entirely way too much for my premix lol.

I buy a jug of Pennzoil Marine 2 cycle for like $25 a pop. Then I've got a small 16 ouncer and a funnel. Pour in 8 ounces/ tank and I'm fine. No mess, no spillage, just takes a little effort.

No OMP and my 87 TII has run beautifully even after sitting the last 5 years.
PLUS It lets me run Royal Purple Synthetic in the case, and that I REALLY like.

So, I take it, if I fill up with 10 gallons every time, and add 8oz of two stroke, that will be fine withought an OMP?

I think that I'll rig up some system to make the pouring cleaner, like using one of those small hand held pumps or something. Thanks for the replies!

i used a small premix bottle that had to chambers in it. the bottom held i think a half quart or maybe more and the top was a "resevoir" with a tube running to it. the outside of hte top had oz markings on one side and 1:50, 1:100 etc markings on the other. you just squeeze the botom to fill the top. and i NEVER spilled with that bottle either. i even rigged a way to refill it when it ran out.

during my rebuild though i had an S$ omp setup on my S5 engine, but i will premix a bit when i start boosting again... i never really had the problem of embarassment at gas stations, although one guy was convinced my car was a diesel because i was adding stuff to the gas. he had a really big farm truck and a reb flag on the back... i couldnt make that up.. haha/....

i heard royal purple is fine for rotary burning via omp. i MAY be switching over soon to check it out.

i always premix 1/2 oz to gallon with or without the pump... on my new car (haha) i only put in 4 oz and filled like 6 gallons.. my bank account emptied out... lol, my next fillup will be 8 oz to half tank aka 8 gallon aka 1:100.. then its gonna be 1/2 oz per gallon... w/e it is.

my friend stop premixing for a year and ran no filter (carbed setup) but the car feels the same.. dunno though we junked the car and didnt have time to pull that motor/tranny too and open it up. it was a vert and we got fed up with the rot and leakage.

i only had one person telling me wtf but he was a worker at the gas station.. i told him, "its my car, you wanna buy it, then you do what you want to it. i like to put oil in my gas."

lol nice

You must think that a 20 year old system should run perfectly without issues, and if it does have issue, then remove it?

How about this, During the tune up that you should do, replace the oil injector lines and o-rings. Replace all the vacuum lines leading to the injectors and everywhere else on the engine. Blow air through the nozzels to make sure they are clean, make sure the check valves are working in the injectors on turboed engines, if not, buy new injectors.

And what is this talk about dirt clogging the injectors? Do you run without a filter?

I buy those containers that are about the size of the antifreeze ones and they also have this pump that just screws on the top. I measured every pump to be 1 ounce and it stores right behind the carpet with the spare. No trouble at all.