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ThisEndUp
10-31-2008, 05:28 PM
Has anyone disabled their oil injection gizmo yet?
I never have trusted those things on my other bikes.

What premix ratio are you using (stock setup...no engine mods...yet)?

random0082
11-02-2008, 07:25 AM
obviously go premix if you wanna anyway, but just to ease your concerns, ive never heard of an oil pump failing on an RS and weve had em in the UK for years. the biggest weakness really is the standard rear shock, its made by Sachs and is crap quality, maybe you have better condition roads over there in the US though? the state of UK roads prob doesnt help

kev13
11-02-2008, 12:54 PM
50:1 is the normal

ThisEndUp
11-02-2008, 06:44 PM
Thanks for the premix answer.

Searching out suspension upgrades also.

:cheers:

HONDARACER
11-02-2008, 07:43 PM
I hit a relativly small pothole today and bottomed the suspension right out. I also blasted full power up a steep twisty hill the other day and found the bike was more like a pogo stick. Definatkly needs better shock damping and heavier springs.

motopix
11-02-2008, 07:48 PM
Do not run 50:1
The only thing you should run that kind of ratio on is a weed wacker or leaf blower.

32:1 ( or 30:1, 28:1, etc) for a two stroke bike.

ThisEndUp
11-03-2008, 07:35 AM
Do not run 50:1
The only thing you should run that kind of ratio on is a weed wacker or leaf blower.

32:1 ( or 30:1, 28:1, etc) for a two stroke bike.

'wasn't going to question the guy......but it did seem a bit excessive.
Thanks for the info.

'did a search and these oil injectors don't seem to have any longevity issues with them.

Onwards to upgrade the pathetic suspension............

iroc07
11-03-2008, 09:54 AM
what have you guys in the UK been using as a rear shock upgrade? how are they working out and what is the pricing?

I would love to see a writeup on the different options.

random0082
11-03-2008, 02:02 PM
If youre lucky you can find an adjustable shock from the 1999 125 SP model, though most will need rebuilding, thats what i did, pic attached. theyre hard to find in good nick nowadays tho. Other options are available from WP, Ohlins, EMC, Maxton, all good stuff. ** Edit. oops, sorry bout the huge pic! thought itd resize it auto

Allen Noland
11-05-2008, 05:22 PM
Has anyone disabled their oil injection gizmo yet?
I never have trusted those things on my other bikes.

What premix ratio are you using (stock setup...no engine mods...yet)?

The recommended ratio on most 2 stroke bikes is somewhere between 24:1 and 32:1. Premix is ok at the track when you have 5 gallons ready to go, but a real pain on the street. Needing to carry extra oil and to mix the gas at the pump is more trouble than it's worth

ThisEndUp
11-06-2008, 06:48 AM
The recommended ratio on most 2 stroke bikes is somewhere between 24:1 and 32:1. Premix is ok at the track when you have 5 gallons ready to go, but a real pain on the street. Needing to carry extra oil and to mix the gas at the pump is more trouble than it's worth

yeah , 30:1 is what I use on the RD.

'Never had a bike this small.....just making sure.

.....and yes, this a track bike, no pump issues.

:cheers:

HONDARACER
11-06-2008, 09:29 AM
I feel that 50:1 is more than enough oil if your using high quality synthetic. Newer outboard motors require 50 to 100:1 mix and you wont see a harder working engine than a boat motor.

I think the old 24-32:1 mixes were pre synthetics and pre water cooling.

Too much oil is probably worse than not enough.

Allen Noland
11-06-2008, 11:28 AM
I feel that 50:1 is more than enough oil if your using high quality synthetic. Newer outboard motors require 50 to 100:1 mix and you wont see a harder working engine than a boat motor.

I think the old 24-32:1 mixes were pre synthetics and pre water cooling.

Too much oil is probably worse than not enough.
The factory recommended ratio on most modern, liquid cooled, 2 stroke motorcross bikes ( Suzuki RM 125-250, Kawasaki KX 125-120) is 32:1. I prefer to be a little cautious with 2 strokes since nothing is worse than not enough oil. I would much rather foul an occasional plug than trash a motor.

catch2otwooo
11-06-2008, 12:33 PM
Too much oil is probably worse than not enough.

no way jose.. fouled plug ( a few bucks) vs trashed motor ($$)

HONDARACER
11-06-2008, 04:15 PM
Dont forget when you are premixing the more oil you add the less fuel that goes through the main jet as its replaced with oil. The excess oil wont burn fully especially at low engine speeds. The excess oil can casue rings to gum up, carbon up and stop sealing properly causeing blowby and damadged cylinders and pistons.

HairBear
11-07-2008, 12:41 PM
Dont forget when you are premixing the more oil you add the less fuel that goes through the main jet as its replaced with oil. The excess oil wont burn fully especially at low engine speeds. The excess oil can casue rings to gum up, carbon up and stop sealing properly causeing blowby and damadged cylinders and pistons.

I'd like to see this one on MYTH BUSTERS

Noassmblyrqired
11-07-2008, 02:13 PM
I'll agree with the shift in fuel throught the main jet. Theoretically... if the oil is 30:1 and your air:fuel is 15:1 (nice round number) that can shift your fuel ratio by a half a point. You also need to take into account the minor increased density/viscosity (Bernoulli's equation) that effects the "signal" on the main jet. From a racing point of view that's a fair amount of deviation from what is optimal. And if your running on the very edge of lean .5 or even .7 slide to lean could very well mean a melted piston!!! If you go as high as 24:1 or 20:1 it becomes even more significant.

You also are carrying less energy in your tank. Many (smart) race teams try to carry as little weight as possible. They only put as much fuel in as they need. You cold come up short on fuel at the end of a race with the same fuel mass.

HairBear
11-07-2008, 03:08 PM
I'll agree with the shift in fuel throught the main jet. Theoretically... if the oil is 30:1 and your air:fuel is 15:1 (nice round number) that can shift your fuel ratio by a half a point. You also need to take into account the minor increased density/viscosity (Bernoulli's equation) that effects the "signal" on the main jet. From a racing point of view that's a fair amount of deviation from what is optimal. And if your running on the very edge of lean .5 or even .7 slide to lean could very well mean a melted piston!!! If you go as high as 24:1 or 20:1 it becomes even more significant.

You also are carrying less energy in your tank. Many (smart) race teams try to carry as little weight as possible. They only put as much fuel in as they need. You cold come up short on fuel at the end of a race with the same fuel mass.

This is starting to get confusing....so let me see if I've got this right. If I block of the oil injection and use a 32:1 premix, I will need to increase both the mainjet size and the air:fuel setting by 1.03125. Mine has a 185 main jet, so I need to install a 190 and turn the air:fuel screw out an additional 11.25 degrees.

HONDARACER
11-07-2008, 06:06 PM
Did your bike come with the 185 Main jet? Also what number slow jet 45?

HairBear
11-08-2008, 11:40 AM
Did your bike come with the 185 Main jet? Also what number slow jet 45?

Mine is an '06 E3 (11kw) that was converted to full power, 185 main jet and 45 slow jet.

kev13
11-08-2008, 08:37 PM
Do not run 50:1
The only thing you should run that kind of ratio on is a weed wacker or leaf blower.

32:1 ( or 30:1, 28:1, etc) for a two stroke bike.

y not run 50: 1 mix ????? the lads in the uk have been doing it for years on that mix with no problems when there have gone pre mix

what mix do you think the oil pump is giving you ? no were near 32:1 30:1 or28 :1

Socket
11-09-2008, 12:49 AM
On my KTM's I always ran 60:1 with motorex full syn...

But I have no idea for the ape.

Gluge
11-12-2008, 08:41 AM
yea it depends on the oil, and machine. Injector systems don't inject much - 120:1 etc. you can measure it based on fuel usage and oil tank usage. But it's not much. However most injection systems inject it right at key points so you'll want to run a higher ratio if you go premix only.

On my saab I run 80:1 premix with high quality synthetic, it injects about 140:1 with the injector motor though.

On my honda RS125 I always run 30:1 though even with high quality synthetic. Which is as per the manual.

Dirtbikes I do about 60:1 so it just varries. I'd say your fine with 50:1 though, you'll want to run a bit more if your racing vs street too. You should be able to feel it out a bit.

Stretch
11-13-2008, 02:21 AM
This whole "less oil is better" is a huge myth. Try searching for an article done by Jennings at "Cycle" mag many years ago which dispelled this myth thoroughly. More oil = more power, less scuffing, less gumming. Their conclusion was use as much oil as the ignition can handle. Here the fast 2 strokes race with 20:1 Motul premix synthetic

HONDARACER
11-13-2008, 10:17 AM
How could MORE OIL cause LESS GUMMING?Does the extra oil wash away the extra oil? Perhaps years ago before synthetics that may have worked.

motopix
11-13-2008, 10:19 PM
More oil = better cooling & lubrication = better power. The differences in gas/oil mix are minute in terms of jetting. I think Bell's book has some empirical data if you need proof.

It's your choice.

Steve / AF1 Racing
04-06-2009, 03:06 PM
We just received these 1/4 turn fuel caps.

If you're going to go pre-mix only, it helps to not have to play the key dance when getting to the oil bottle under the seat.

http://www.af1racing.com/store/Scripts/prodView.asp?idproduct=7283

http://www.af1racing.com/store/ProdImages/st2/YOAGTAP022N_RS125_d.jpg

kanerdog1x1
04-06-2009, 05:16 PM
i agree on the 50-1 ratio in an off road bike, i would run either 50-1 or 60-1, depending on the weather and the route/company. but the ktm wouldnt be at sustained high rpm like the road bike is, so i would start at about 30-1, to be on the safe side.

kanerdog1x1
04-06-2009, 05:17 PM
and we get those filler caps from harris in the uk, they are works of art, and the snap you get when you turn it to the closed position-pure sex!

Sududri134
04-06-2009, 07:48 PM
I've been over at an Kawasaki dirtbike forum for a while now, and everyone there mixes from 1:32 to 1:50, most common is either 1:32 or 1:40.

That is for the KX125's, maybe they are more race oriented than the RS'es are, I don't know.

I run 1:36, with fully synthetic Elf two-stroke oil.

NOTE: Post might seem meaningless, but atleast you guys now know what is most common for 125cc race engines in MX bikes :cheers:

ThisEndUp
04-07-2009, 06:23 AM
Not meaningless at all....

:cheers:

becyk
08-18-2009, 12:45 AM
Here we go again...

I want to run premix too, gonna go 32:1, do you guys remove the oil pump and if you do, do you need a blocking plate to cover the hole? I'm guessing you do, just double checking.

Skywave
08-26-2009, 12:59 AM
I also decided to go pre-mix. This definitely isn't a touring bike. I have no problem taking the time to add oil.... it's piece of mind.

And I think it's laughable that people are shocked at someone suggesting running 50:1...... No WAY is the oil injection system coming close to that. I did the math on the pre-mix compared to what the bike was burning automatically. You'd end up going through way more oil with even a 50:1 premix than the automatic injection set-up..........

Personally, I don't trust automatic oil injection with a 2 stroke motorcycle....on a lawn mower, no problem. but not when im riding on top of it at 100MPH. that's just me. 4 stroke, no problem....

Socket
08-26-2009, 03:57 PM
I agree with skywave, but I still roll my RS125 on the street only.

becyk
08-26-2009, 11:05 PM
Do you just remove the pump, cover the hole with blocking plate and run 50:1 in the tank???

I'm a little worried of the 50:1 mix but what do I know??

Are you racing/tracking this bike at 50:1 now?


Thanks for your input
Richard

Dieterly
09-09-2009, 12:38 PM
I just removed the pump, and made a blocking plate to fit over the opening. 32:1 seem to work fine for me.

Magnus

Skywave
09-22-2009, 08:26 PM
becyk,

32:1 is fine. In fact, you should start at that mix and monitor it, and than only go leaner if you notice things like your spark plug fouling or a crazy amount of smoke coming out of the back. When I mentioned 50:1, it was more to say in certain cases, that could be normal for a particular set-up.

I would have a professional set it up. That's what I did. This isn't my first 2 stroke bike, but it is the first time I decided to go pre-mix. My first bike worked perfectly, no problems. This one wasn't set-up properly during PDI, and never pumped oil properly, without me knowing it. After that, screw it, had the entire system disconnected.

Now, if I have another oil problem, I know who to blame, and I'm more comfortable with that.

Stretch
01-21-2010, 08:55 AM
Using the oil pump makes sense for a streetbike but if the temp rises with an increase in vibration, STOP and check the balance gears - they also drive the water pump and oil pump. Premix is fine for racing. Once again read Jennings for a definitive answer as opposed to conjecture re premix ratio. Just remember to adjust the jetting accordingly. 20:1 is cheap compared with a dnf and subsequent rebuild.

Roadstergal
12-31-2013, 02:53 PM
If you're going to go pre-mix only, it helps to not have to play the key dance when getting to the oil bottle under the seat.

So what ratio do you guys recommend? :)

magus
01-01-2014, 10:01 AM
This makes a lot of sense. I was recommended to start at 28:1 by "the" source (AF1) and asses from there. This was for a track-only, race set-up, so the thinking was to play it a little safe and go from there. Has worked fine so far.



becyk,

32:1 is fine. In fact, you should start at that mix and monitor it, and than only go leaner if you notice things like your spark plug fouling or a crazy amount of smoke coming out of the back. When I mentioned 50:1, it was more to say in certain cases, that could be normal for a particular set-up.

I would have a professional set it up. That's what I did. This isn't my first 2 stroke bike, but it is the first time I decided to go pre-mix. My first bike worked perfectly, no problems. This one wasn't set-up properly during PDI, and never pumped oil properly, without me knowing it. After that, screw it, had the entire system disconnected.

Now, if I have another oil problem, I know who to blame, and I'm more comfortable with that.

maddad
01-01-2014, 02:02 PM
The yam I have on av gas is 33 :1 ,that's almost always full throttle :)

vfracer-r
01-01-2014, 08:52 PM
Magus et al; we have been running 32:1 with 93 pump gas. Plugs look lovely and the power is as good as it was (if not better by seat of the pants dyno).

For racing, we are going to run the Sunoco 260GTX 98 octane fuel with Motul 2T at either 28:1 or 32:1.

magus
01-02-2014, 08:21 AM
So is that Sunoco 260GTX 98 fuel significantly different than the C12? I'm having to learn about all these racing fuels now.

I think the 28:1 for me had to do with the fact that the "parentage" of my RS is so unknown that it was smart to play it a little cautious.

vfracer-r
01-02-2014, 11:08 AM
I don't think 28:1 vs 32:1 makes that much difference. No worries on err'ing on the side of caution though. I don't think you're going to foul plugs between the two ratios.

As far as fuel goes, the Sunoco is the AMA spec fuel and is cheaper by the gallon. According to some quick research it also has a few less additives than the VP has, both are very clean and fantastic alternatives to pump fuel with ethanol.

Can't go wrong with C12 or the 260GTX, both will do great, the Sunoco is just cheaper.

Sonic_Uk
01-23-2014, 08:32 AM
To be honest I've never premixed - don't see the point whe the Rs has an auto mixing system which is pretty reliable from what I've read. Plus I cant be bothered with all that hassle/mess at the pumps when its time to fill up if its not necessary. I top up the oil once a week or after a long journey and leave it at that and its been ok for me so far since owning the bike in July (I did the same on my old derestricted 50cc ped I had a decade ago which managed 22,500 miles on the original engine from new with no issues).

magus
01-24-2014, 03:51 AM
If you are riding on the street, I agree but for a dedicated track bike it's different.

vfracer-r
01-24-2014, 11:49 AM
To be honest I've never premixed - don't see the point whe the Rs has an auto mixing system which is pretty reliable from what I've read. Plus I cant be bothered with all that hassle/mess at the pumps when its time to fill up if its not necessary. I top up the oil once a week or after a long journey and leave it at that and its been ok for me so far since owning the bike in July (I did the same on my old derestricted 50cc ped I had a decade ago which managed 22,500 miles on the original engine from new with no issues).

These are race bikes and the oil reservoir and pump is removed.

Sonic_Uk
01-26-2014, 07:22 AM
Ah I see, my apologies! I assumed the op was talking about a normal street bike!

magus
01-26-2014, 07:38 AM
Ah I see, my apologies! I assumed the op was talking about a normal street bike!

You are right, OP was talking street. I guess the thread deviated a little ;)