Oil metering pump

[rustyrescue]

When I first started the re-commission of our FB I checked the oil output of the metering pump and set the rod to the carb.
Having just refitted the carb following work I have found the metering pump lever is stuck in the up/high oil dose position so something has gone wrong.
Should I sort the pump or switch to premix?
If the 2nd option which 2 stroke oil do people use and what ratio mix?

[Hobbawobba]

I would give the OMP a good look over and make sure it is nothing simple aye

If removing. I use Exol Racing 2T at 10ML per litre aye. Like this stuff - I bought a 5L last time. Might get this one next Haha. Then I decant it in to an old castrol 2T bottle that has measurements on the side. Nice and easy!
https://www.ebay.co.uk/itm/EXOL-FULLY-S ... 635-2958-0

It's mega cheap in comparison to many others and it also meets the best JASO standards. They dona few different 2 stroked. Here is some more info on it
https://www.exol-lubricants.com/product ... ycle-oils/

[gt_james]

I think having the OMP at full all the time isn't too bad, I think some people do this on purpose. Obviously you will drain the sump of oil even faster, so the oil level would need checking religiously. I've never run an OMP like this myself. It could also foul plugs quickly. I aim to check the oil level every other or every 3 times I stop at a petrol station.

On my 12A cars with the OMP working I premix 4ml/litre.

On my cars with the OMP removed and premix only, I use 10ml/litre.

I've used castrol power 1 racing 2T before, its easy to get in halfords and some petrol stations, and is a handy bottle for pouring, with a basic scale on the side, great specs, and I would use it still, but it is expensive though, so I switched to EXOL. EXOL Optima is half the price and the spec of the oil is excellent, I think a few people have switched to using it now, like Jesse. I have found them very easy to ask questions about, emailing their support guys, it was easy to ask about E10 etc, so that's another plus for me.

Motul do some good premix, and there is also Idemitsu which is developed for rotary engines. They're very expensive though.

I think sticking to a synthetic premix with JASO FC or higher spec is best, and I would avoid the cheap scooter/garden equipment stuff, as well as avoid caster based pre mix.

good premix shouldn't separate from petrol for months and months, although modern E10 petrol will separate by itself, so if you're leaving your car for long periods with premixed fuel in the tank, the ethanol could separate out and you'll have a portion of ethanol separated in the tank. I have started using ESSO premium fuel as it has no ethanol in it still, so it's less to worry about storing over the winter.

[ian65]

My car has been premixed with castor all of its life while still running the omp with no ill affects whatsoever.
Original engine, never rebuilt and still testing almost as good as new

http://www.rx7fb.com/viewtopic.php?f=4&t=27&start=130

Yes I know all the alleged reasons why castor shouldnt be used but that’s not Daves or my experience with this particular car going back decades..... R40 all the way for me.

[gt_james]

How do you deal with cars being stood with castor in the tank? It will separate out the fuel. OK for bikes and things that can be shaken up, tricky with a car.

[ian65]

How do you deal with cars being stood with castor in the tank? It will separate out the fuel. OK for bikes and things that can be shaken up, tricky with a car.

dunno James, it's never been an issue. You would think that it would be and all opinion points to it being an issue but it never has been with this car either over the 26 years that Dave owned it or the nearly 3 years that I've owned it. Maybe it's the mix ratio... it's always run 200ml per tank full so maybe it's too diluted to be an issue.... don't know ... all I do know is that it's always run it, it's never missed a beat and it's putting out compression readings nearly as good as new on it's original lump after 32 years so I'll stick with it unless it suddenly starts coughing and spluttering.

I might do a bench test with some unleaded and some R40 and see how long it takes to separate..... modern unleaded is pretty horrible stuff so maybe it acts more of a solvent on the caster and keeps it fluid?
Next time I buy some super unleaded instead of that eco shit I'll do a test and post the results