oil injection... worth using/tuning?

csteel100_131.jpg

we'll assume in their "ideal gas/oil ratio" chart that speed = rpm.

premixing means you get a 1d map... a single ratio at all operating points. however, the above chart indicates it should be a 3d map... one axis rpm, one axis load.

this appeals to me intuitively, but it can only be achieved by crankcase driven (RPM) oil injection (OI) with a throttle cable input (load).

stumbling blocks: we can assume the oems tuned their OI for their stock engines. in order to tune our own we would need to 1. know fuel consumption at various operating points 2. the ability to adjust the displacement of the pump (RPM axis) and 3. the ability to adjust the rate increase due to load (throttle axis).

unfortunately although there are theoretical improvements with an ideal OI rig, i see the technical hurdles as making it challenging to execute. meanwhile i target the bottom right of the chart with 20:1.

has anyone modified/tuned their OI setups? if so, could you provide any feedback/lessons learned/etc?

ken

Re: oil injection... worth using/tuning?

Seems like it would be fun to try, but in my experience, their never trust worthy. Even in factory configuration, if it fails, so does your bike. Using the OI has never been worth that risk to me. In theory, if you could increase the volume of oil being pumped to match what your kit needs at idle, then it would deliver the correct amount at any rpm. At least if the pump is driven directly from the crank. Let us know what you come up with!

Re: oil injection... worth using/tuning?

Probably Fred /

If you want a higher oil ratio leave the Enduro bike injection alone because many bikes you want to inject right at the crank bearings and if you want more just add some premixed 2t to the tank

Re: oil injection... worth using/tuning?

I learned with a old old Villiers engine to not trust auto oiling. Anything rare or hard working I use bean oil, the rest get dino oil.

Re: oil injection... worth using/tuning?

https://www.mopedarmy.com/forums/read.php?7,4217634

It got discussed here^

I was pondering whether the oil demand would be more closely related to amount of friction, thus dpenedent on the RPM of the engine, or number of cycles wiping the piston against the walls (like each revolution needs a set amount of relubrication) or if instead it there was a heat effect, more gas being burnt = more heat = more oil demand? or if there was a washing effect of the gas on the walls, in which case more gas in meant more oil need; demand again related to amount of gas going in.

Essentially asking whether the amount of oil supplied should better be proportional to engine speed (injector), or to amount of gasoline (premix)

.

no consensus. but in general my takeaway was that a GOOD oil injector is superior to premix, such as that yamaha system or high end 2 stroke scooters or full 2t motorcycles. Meanwhile moped injectors are NOT "good" oil injectors, and best avoided.

Re: oil injection... worth using/tuning?

Oil demand or need is similar to any other system on a engine (ignition timing, air fuel mix, cooling, etc) and will vary based on speed, load, temperature, (etc). So unless someone is going all out with a complex CPU so folks can chip-tune like they do with automobiles, then everything is a compromise. With the ideal being digital injection would be superior to mechanically mapped pumps, which are superior to just the basic fixed flow pumps, which is superior to premix. Failure of being able to deliver would be the weakness of any of those systems. Premix being the only one where component failure would be the person refueling not mixing the correct ratio (or using shyty oil) - the common flaw on all of them is forgetting entirely to add oil (to the fuel or to the tank).

I suppose one day I will become old and feeble and forget more and more and one day I might forget to premix and will start locking engines. I have run out of fuel on a number of occasions (most everyone has done this more than once, anyone who says they never has is likely not telling the truth), but at least locking a engine will not be because I forgot to fill the oil tank.

> Born to be WillD Wrote:

> -------------------------------------------------------

> https://www.mopedarmy.com/forums/read.php?7,4217634

>

> It got discussed here^

>

> I was pondering whether the oil demand would be more closely related to

> amount of friction, thus dpenedent on the RPM of the engine, or number

> of cycles wiping the piston against the walls (like each revolution

> needs a set amount of relubrication) or if instead it there was a heat

> effect, more gas being burnt = more heat = more oil demand? or if there

> was a washing effect of the gas on the walls, in which case more gas in

> meant more oil need; demand again related to amount of gas going in.

>

> Essentially asking whether the amount of oil supplied should better be

> proportional to engine speed (injector), or to amount of gasoline

> (premix)

>

> .

>

> no consensus. but in general my takeaway was that a GOOD oil injector is

> superior to premix, such as that yamaha system or high end 2 stroke

> scooters or full 2t motorcycles. Meanwhile moped injectors are NOT

> "good" oil injectors, and best avoided.

Re: oil injection... worth using/tuning?

ken gilbert /

thank you for the thoughts.

i agree that at the end of the day, simplicity is the biggest contributor to longevity.

a system in which is there is no way (for a mechanical, non-human failure) to get gas without getting oil is the simplest possible.

Re: oil injection... worth using/tuning?

Dirty30 Dillon /

Oil Injection is really helpful in many ways, and I will typically leave it unless the bike is going to be heavily modified.

Re: oil injection... worth using/tuning?

Yea, I think for me motivation for ditching the oil injector was the likelihood of minor issues causing major problems. I've had some fail in the past. But like, you get a kinked or leaky fuel line, your bike dies and you fix the fuel line, probably in less than a minute with no more tools than a pocketknife.

But an oil injector line kinks or clogs or leaks out, and sorry bud. game over.

Re: oil injection... worth using/tuning?

I've got a TX50x that I kept the oil injector on but only after meticulously doublechecking function, bleeding it, and replacing hoses. After a few years of flawless operation I removed it after kitting and rebuilding, partly for worry about the bigger bore needing more, and partly to use the space that used to be the oil tank for more useful stuff like tools and well, oil to premix.

I had an MB5 with oil injector, that also got deleted after kitting.

I've had a few tomos with oil injectors that I used, and 3 which failed. all failed open, the worst one wound up dumping an almost full oil tank straight into the cases.

I only had one that failed to seize - honda express SR, not sure exactly what went wrong, but it went wrong, thing got crazy hot, started dieseling and wouldn't shut off, then seized.

I had a sachs seville that had an oil tank that made for a very hand secondary auxiliary gas tank when i deleted the oil injector. i never tried it but it was driven off the flywheel by a rubber bushing that was pretty cracked and couldve easily & likely failed.

Really very few mopeds i've trusted the oil injector and more than half of those failed, only like i said "good" injectors have i trusted, that on 2 stroke motorcycles, and even then I prefer the simplicity and less risk of just premixing.

Re: oil injection... worth using/tuning?

Probably Fred /

Ken Gilbert you didn’t state what bike you were talking about for some Japanese 2 stroke motorcycles need the oil injector because the oil injects at crank bearings and running pre-mix it will not get enough down in there like I tried to say earlier,

Most mopeds you can bypass/eliminate the oil pump and enough oil will get to the bearings,

Re: oil injection... worth using/tuning?

Dirty30 Dillon /

Many of the Suzuki's with injection you weren't able to premix because one half of the oil valves ended on the crank bearing, which would not receive oil from pre-mix because there was a slinger in the way.

They run for awhile like that, but eventually need to be rebuilt

Re: oil injection... worth using/tuning?

my suzuki just dumped into a little bung on the intake, same as tomos and lots other stuff

Re: oil injection... worth using/tuning?

Probably Fred /

> Born to be WillD Wrote:

> -------------------------------------------------------

> my suzuki just dumped into a little bung on the intake, same as tomos

> and lots other stuff

Must not have been a small motorcycle which in some states can be a Moped

Re: oil injection... worth using/tuning?

Dirty30 Dillon /

> Born to be WillD Wrote:

> -------------------------------------------------------

> my suzuki just dumped into a little bung on the intake, same as tomos

> and lots other stuff

All the TS's I had were, but I think because of the issues involved, that idea was abandoned.

Re: oil injection... worth using/tuning?

I just went down a wild hole. So I have had a JR50, and RG50 and my TS50, all pretty much tryna be 2 stroke motorcycles. maybe not the JR. My TS is late model, like 200, with the liquid cooled RG engine. but they all just had oil pump from the case squirting into the intake between carb and reeds. But then i found some folks claiming that the oil pump itself has a tiny dedicated side channel going to the crank bearings. Which i suspect is totally false. but it would mean that deleting oil injection is gonna fail main bearings.

Anyway, my certainty is crumbled.

I also found some old patents claiming these additional benefits: better lubrication, less oil demand and lower emissions because injected oil comes in it's bigger droplets, so less is burned, less is blown out with the charge, and more winds up coating surfaces as intended. beside just being easier for refuel and avoiding people mixing in tank, which can be problematic.

But you contrast that with added system complexity, it has higher chance of failure, and oil is obviously very critical and very high chance of damage if it fails. And that's why I'm mostly all premix.

Plus, I think the danger of someone forgetting to fill the oil reservoir is equal or greater than the risk of forgetting to premix.

Re: oil injection... worth using/tuning?

Did saab 96's and the like use oil injection? What about 2t boats? My immediate reaction is that these industries would have more data behind their models.

Re: oil injection... worth using/tuning?

ken gilbert /

i have to say i'm fairly impressed at the robustness of my chappy's OI system. i don't have a lot of experience with other mopeds/2ts of the era, but i wouldn't be surprised if someone told me that yamaha was putting identical OI pumps in all their lineup.

that's interesting about the benefit of having larger droplets of oil via injection vs atomized/vaporized fuel-oil from the carb.

Re: oil injection... worth using/tuning?

I have an oil mixer for a boat which I believe is a vro. If anyone wants it to automatically premix for you let me know and I might have it available for sale.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account