To premix or not to premix, that is the question

[rotatopotato]

Fluffy, indifferent feline creature - worshipped by the ancient Egyptians (for some reason )

[Magsrx8]

The collective knowledge here is seriously impressive. Thanks for your input.

So I'm reading that ultimately I need to decide upon either a SOHN adaptor and map, or a RRP COFS and premix?

[rotatopotato]

none of the options are mutually exclusive.

rrp cofs vs sohn. either do the same job, but the rrp cofs imho is a better design. id fit one whatever else you decide to do.

map, again, not a either or choice, again id get it done, whether only a mini map for the cold rev limit and increased omp injection rate or go the whole hog and get it mapped fully.

premix. again not either or. whether you do either or both of the above 2, it is still wise to premix.

[rotatopotato]

[Magsrx8]

So (SOHN or RRP COFS) + (mini or full map) + Premix = Happy engine that will have every chance of staying that way

[rotatopotato]

Yup!
If it were me, I'd be going with RRP COFS, a mini-map, and of course premixing. They're not mutually exclusive but all compliment each other to give you thousands of miles of happy rotoring!

[rotatopotato]

And a side note about the COFS/SOHN adapters - there is the adapter itself, plus you need a tank solution. RRP offer one, it is beautiful, but it is also pricey and there are other options out there if that isn't to your taste. Not to mention it is something you can whip up any number of custom solutions for - I believe some club members have had great success using 2t tanks from certain 2t motorcycles, and have incorporated their level sensors into the oil level sensor wiring (RRP also have this with their tanks, I'm using a kit from epitroch in the usa on ebay in my 192 which doesn't have level sensors).

[Milos_Balunovic]

For adapter I actually built my own where the shaft is supported with special bearing bronze (none awailable run this option) and special hardened nitrated shaft self priming, etc, and got a tank for an RC car or minibikes have the same (1L) that i hang from crossbar.

First world problems eh?

It might be a problem in first 5 minutes. By the time engine gets hot its not a problem as all the pipes and OMP get heated to that temp..

The issue is that the 2t source in the tank doesnt get that heat, and neither will the pump I'm using (and that first 5min still needs a solution or I risk wearing out the pump prematurely). I'm thinking for extreme cold in winter a silicon heat mat attached to each side of the tank and hooked up the acc circuit for pre-heating will be a decent solution. But it may not be required, I'm just thinking ahead for belt & braces solutions.

I say COFS because it's shorter than saying clean oil feed, which is all I mean - whether it's a SOHN, and RRP COFS, or a custom solution, they're all clean oil feeds so it's just a catch-all term for me

Its notnthat thicknthat it wont be pushed itsnjust hard to push ie not really going to flow nicely.
Motul800 off road is one of them that is not recommended for a OMP pump (gravity feed) on 2t bikes. But is very heavy (mixing in racing app is 1 to 1.2%) and will make a lot of oil (not carbon ! ) deposits in exhaust. Ie impossible to ignite and burn off. While 800 road racing is mixed at 4% but flows "lik water"

Sorry for digression. I really don't think you'll have a problem feading the OMP pump with any sort of pressure. The flow problem is within the OMP which heats up quickly and heats up the oil it self quickly. Also I would consider having that pump immersed in the 2t tank it self.....

[rotatopotato]

Unfortunately it's a bit big to fit inside the tank!
Aye, I don't think there will be an issue with flow, and actually I just happened to be doing a little more looking as the chart I was using to get the kinematic viscosity at a range of temps was based on a viscosity index of 100, whereas the ZFS is 166 so will have a flatter line on the chart meaning it's very unlikely to get anywhere near 350cSt at any temp. So I should be golden

[Viperous]

It's going to sound like a really daft question, but do I put the 2 stroke in before I fill the car up or after (and will it make a difference)?

Will ratio 20ml to 10 litres of fuel as per posts above. Someone recommended Castrol 2T so that's what I've ordered

[PaulAV]

It shouldn't matter either way, as long as you can actually fill up after adding the 2 stroke oil it will mix, the down side to adding it after is some will stay in the filler neck where as adding it first allows the fuel to wash it into the tank. But either way fuel and oil will mix

[Viperous]

Great, thank you

[Mazzarx8]

I’ve just bought a cofs from rrp I plan on using 10/30 mineral in the cofs, fully synthetic in the sump and still pre mix in the tank. Maximum lubrication or is this to much May as well produce the emmisions, I pay the tax for it

[PaulAV]

If you want to really go for it get your omp infection rate increased, you should be fine though

[Viperous]

Premixed for the first time at the weekend - £92 to fill up! And it wasn't even 99 octane as BP super unleaded is only 97 - been making a habit of only using 99 octane.

Just a thought off the back of this, I saw a video on Youtube by 'Driven By Madness' who said it's best to stop premixing a few months before your MOT emissions test or you won't pass it. Is this correct? MOT is due at the end of July.

[qwakers]

Mine passed the mot but only just scraped through on hydrocarbons. I had about 400ml of premix in the tank at the time.

[Milos_Balunovic]

I've been premixing every tank since 2008, @100-150ml per tank (300ml on track days), and not had issues with emissions tests with oem cat.

I've also been active on this forum for the same period and have yet to see anyone post a first- hand report of an emissions fail due to premixing.

Sent from my Samsung using Tapatalk

[PaulAV]

Although if your cat is marginal you might want to help it pass as much as you can

[RenesisRaceBuggy]

That's okay, stick some E10 in it and it'll burn cleaner for emissions now anyway.

[Steve.82]

Will it make a difference? As far as I can tell the ecu targets lambda, not AFR?

[Viperous]

I've been premixing every tank since 2008, @100-150ml per tank (300ml on track days), and not had issues with emissions tests with oem cat.

I've also been active on this forum for the same period and have yet to see anyone post a first- hand report of an emissions fail due to premixing.

Sent from my Samsung using Tapatalk

Reckon I will just chance it then. Would rather the engine was happy so I shall continue to premix up to the MOT and then we shall see what we shall see.

[rotatopotato]

I was pretty heavily premixed on a cheap cat and passed the most recent mot without issue, and that's on questionable plugs & coils too.

[DomN]

Hi all, sorry for what's probably a stupid question. But Castrol power 1 2T, or 2T racing. Does it make a difference? Is the "normal" 2T fine to use?

Ta

[PaulAV]

Considering some people don't premix and some use a variety of oil for premix I can't imagine there would be much difference between the 2, certainly not enough to notice anything, but that's just my thoughts

[DomN]

You can use Strawberry Scented scooter oil if you want, as long as it says "suitable for premix" on the bottle.
Also confuses the hell out of the traffic behind