To premix or not to premix
 

While premix makes a degree of logical sense in terms of lubrication, I have one question---what effect does a premix have on the injectors in terms of dispersal pattern and fouling?

Premix gas, which is really nothing more than adding two stroke oil in a small ratio (usually between 30:1 and 70:1), has historically been used in two stroke carbuerated engines, from chainsaws, lawnmowers, outboards to motorcycles. The OMP, as I understand it, dumps the oil into the mix post-injector. Before I bypass the OEM injection system or augment it with additional oil, I would like some definitive data on the effect of a higher viscosity than spec'd fluid being put through a metering jet.

Since it's added lubricity, it should help the injectors.

I know of some people who had FCs with the infamous leaky injector flooding problem, and premixing actually made it much better if not totally solved.

Premixing is good for your motor and your injectors. I used to use redline two stroke oil. However if you use too much then it will lower the octane of your gas. For street you may want to use a 100:1 mixture, but for the racetrack with race gas, you should use 50:1

doesn't the OMP mix ratio work out to be like 267:1 or something equally as odd and high, everyone i have talked to said 100:1 for a race motor and around 130-150:1 for a street motor

HWO it depends on which engine you're talking about!

Carby 3mm seal engines range from 150:1 to 400:1. Injected 3mm seal engines are less than that because they have one of the injectors right at the rotor housing (so more of the oil goes where it's needed) and the injected 2mm seal engines are even less. Plus they made changes with every serioes that kept reducing the amount of oil used.

I mixed at roughly 128-150:1 (no OMP) with a carby 3mm seal engine and had no problems at all :)

I recently started premixing a couple of weeks ago on my 88n/a. I did It right. Blocked off the Injectors, oil lines and OMP.

Infact, a month prior, I replaced the Oil metering Lines b'c they were rather black. To my dismay, I found all the lines CLEAR except one of them. It had bubbles In It.

I since have noticed far better start ups and FAR better smoothness all across the power band. In short, I really recommend to replace the Oil Metering Lines to see If the OMP works! I can't stress this enough! Mind you, that Is If you plan on keeping the stock lubrication set up. But If you don't mind the "nusiance" of dumping 16oz. every FILL UP, by all means go a head. Run pre mix. In the long run your motor and wallet will benifit!

Sounds good, Im gona try it on my TII just with some castrol GTX ( realy want to try my loved Sythetick)....let yall know.

How much should i add per galon? capfull?

I think a really good question would be for some one to find the stats on how much a synthetic leaves behind when it burns from brand to brand (this is called ashing) usaly oil with a wider viscosity ( 15-50 insted of 10-30)
laves more behind do to the visco-enhansing polimers. i have seen these stats somewere (mobil one is close to the lowest proforming sythetic, quakerstate was great, especialy for turbos!) It sounds crazy but these numeric qualitys are given to all oils (about 8) when they are to pass the SAE aproved test.

The TC-W3 standard virtually guarantees them okay in fuel injection applications.



-Ted

Whoo. A blast from the past. I guess I can add to this thread from my original posting of this thread, seeing how It's been a year ago.

All the benifits still stand, as originally stated. I have noticed, however, that my O2 Sensor keeps crapping out on me. Since I started premixing, I have went through two O2 Sensors!

*EDIT* Anyone else going through O2 Sensors like underwears?:D

I ran Valvoline Multi-Use premix and never had a problem with the O2 sensor dying.


-Ted

I have been using Castrol Super Outboard Motor Oil, certied TC-W3.

:werd:


Original poster- Search the second gen section for pre-mix or MOP/OMP removal. Under my name I have a nice little write-up that AMUR_ edited for me and I based on what REted had on his website.

I truely stand by pre-mix as FAR superior to the MOP system. Please take the time to read the full thread as it has many points to it not just the mod itself.

Santiago

PS- you N/a guys check out the intake in my sig. TII guys wait a couple of months are there will be a TII intake. :D

I've also heard this from a few other fellow FC owners.

If you ( Jeff ) do not go to pre mix ,get the 2 cycle oil ,air plane thinge that Garfinkle has . He will make you a tank and set it up for you . He made a two champer tank for Rotorbrain that holds 2 cycle oil and is a catch can breather .