Premix vs. Yamaha autolube question....
Tim Richter
I am reviving an old Yamaha DT125 and it has the
engine with the Yamaha autolube oil injector. A guy at the
Yamaha dealer stated that I should disconnect the oil pump
and run premix of 32:1 using Yamalube 2-R racing two stroke
oil. He stated that if the oil pump ever failed, you'd never
know it until it is too late and you can never go wrong using
premix. My understanding was that the autolube system was
designed to deliver a different mixture ratio depending on how
hard you were cranking the throttle.
Any thougts?? (I'd rather just run premix as the oil
tank is damaged and I'd have to repair it before
making it work)
Thanks
Tim Richter
Chris Buckley
Tim Richter wrote:
>
> Hello-
> I am reviving an old Yamaha DT125 and it has the
> engine with the Yamaha autolube oil injector. A guy at the
> Yamaha dealer stated that I should disconnect the oil pump
> and run premix of 32:1 using Yamalube 2-R racing two stroke
> oil. He stated that if the oil pump ever failed, you'd never
> know it until it is too late and you can never go wrong using
> premix.
Good advice.
My understanding was that the autolube system was
> designed to deliver a different mixture ratio depending on how
> hard you were cranking the throttle.
Correct, which is exactly what happens with pre-mix, the more you twist
the throttle, the more fuel and oil you get.
> Any thougts?? (I'd rather just run premix as the oil
> tank is damaged and I'd have to repair it before
> making it work)
Yes, take the auto-lube off and throw it away!!!! Auto-lube was designed
as a convenience for 2-stroke road and dual sport bikes, so that they
can be refueled on the road without having to stop and mix fuel, 1 tank
of oil would last for several tanks of fuel. The first thing anyone
would do when converting an oil injected bike over for racing, was to
remove the auto-oiling system. Suzukis are a different story, some
Suzukis used the oil pump to lube the crankshaft bearing on the right
side of the bike, requiring one to drill a hole in the case to allow the
pre-mix to get to the bearing.
> Thanks
> Tim Richter
You're welcome,
Chris
brokein2
"Tim Richter" <hond...@comcast.net> wrote in message
news:3dd6641e...@news.tn.comcast.giganews.com...
The autolube does not vary the Oil/Fuel ratio as such. It merely feeds
varying amounts of oil according to your throttle position. More throttle =
more fuel = more oil.
You would be much better off just mixing your own fuel - thus having the
option of mixing at different ratios.
Brokein2
Wudsracer
Tim,
What you are considering is fine for a Yamaha, but death for a
Suzuki's crank bearings.
If you , or anyone else who has an "auto lube" system, chooses to
retain the system, check the lower throttle cable (after the cable
"splits"that operated the oil pump frequently. The cable going to the
carburetor can still be working after the cable to the oil pump
breaks. This is also death to an engine.
Wudsracer
'99 Gas Gas EC 274
Team LAGNAF
SMACKOVER Racing
www.smackovermotorsports.com
"We Only Ride on Days That End in Y"
cliff
If i remember right, make sure you plug the hose that goes from the
pump to the carb, so no air can enter the carb causing a lean
condition.
Dean H
autolube mixomatic doohicky. I guess you can save a few pounds (and give
up a little fuel range), but the concept is good. It always delivers the
proper ratio depending on lugging around or revving like crazy.
I always figured, if it ain't broke, don't fix it. But your oil tank is
bad, so maybe it's broken. Premix will get you through. If the tank can
be fixed, then just pull the cover off the pump now and then and hose it
down with WD40, keep an eye on the cable, and be happy that you can fill
the tank with straight gas. Then you can share gas with those 4-stroke
doofi, and you can just fill up at the pump if you want. The oil tank is
good for a few tanks of gas, so...
Anyway, I beat the living crap out of that '78 from about, oh, 1992
until about 2000 and it never missed a beat using the autolube. Never
fouled a plug either. Oh, and the linkage was siezed at about 3/4 mix
for the first few years too. That bike is bulletproof, dewd.
Have fun.
-Dean
Tim Richter
Yep. Thought of that... Thanks a bunch...!
I was also thinking that if I removed the oil pump
and oil tank (to save a few pounds), that I
would have to get a good seal to block off the shaft hole.
Thanks for all the help guys!!!
Tim (newbie to 2-strokes)
Eric Murray
Tim Richter <hond...@comcast.net> wrote:
>On 16 Nov 2002 16:21:19 -0800, vff...@cs.com (cliff) wrote:
>
>>TIM
>>If i remember right, make sure you plug the hose that goes from the
>>pump to the carb, so no air can enter the carb causing a lean
>>condition.
>
>Yep. Thought of that... Thanks a bunch...!
>I was also thinking that if I removed the oil pump
>and oil tank (to save a few pounds), that I
>would have to get a good seal to block off the shaft hole.
Yamaha makes a part just for that. It's the same on
all Yamahas from the 70s on. Last time I bought one
it cost under $2.
The Yamaha oil injection system does vary the oil ratio
depending on throttle position. More throttle means more
oil per unit of gas. I used to ride RZ350s. For
regular street riding I'd go about 5 tanks of gas per quart of
oil. At the end my first track day I was suprised to see that I'd
used most of a quart of oil by the end of the day, and only
a single tank of gas.
This the advantage of oil injection systems over premix.
If you premix for serious WFO riding (i.e. roadracing) you
might want to use 20:1 or even more oil. But if you are
just piddling around, easy trail riding or whatever, that
is way too much oil. A good oil injection system like Yamahas
can deal with that and give you the 20:1 when you need the oil
and 80:1 when you don't.
Of course as has been pointed out elsewhere in this thread, if
the oil pump breaks you get a ratio of 0:1. But I haven't
seen any Yamaha oil pumps break, they seem to be pretty reliable.
I suspect that a lot of "oil pump broke" stories were really
"I forgot to put oil in". :-)
Eric
Thomas Potter
There can be alot of convenience in the autolube.
Wudsracer
>Tim Richter <hond...@comcast.net> wrote:
>>On 16 Nov 2002 16:21:19 -0800, vff...@cs.com (cliff) wrote:
>>
>>>TIM
>>>If i remember right, make sure you plug the hose that goes from the
>>>pump to the carb, so no air can enter the carb causing a lean
>>>condition.
>>
>>Yep. Thought of that... Thanks a bunch...!
>>I was also thinking that if I removed the oil pump
>>and oil tank (to save a few pounds), that I
>>would have to get a good seal to block off the shaft hole.
>On Mon, 18 Nov 2002 00:11:43 GMT, sp...@lne.com (Eric Murray) wrote:
>
>Yamaha makes a part just for that. It's the same on
>all Yamahas from the 70s on. Last time I bought one
>it cost under $2.
>
>The Yamaha oil injection system does vary the oil ratio
>depending on throttle position. More throttle means more
>oil per unit of gas. I used to ride RZ350s. For
>regular street riding I'd go about 5 tanks of gas per quart of
>oil. At the end my first track day I was suprised to see that I'd
>used most of a quart of oil by the end of the day, and only
>a single tank of gas.
>
>This the advantage of oil injection systems over premix.
>If you premix for serious WFO riding (i.e. roadracing) you
>might want to use 20:1 or even more oil. But if you are
>just piddling around, easy trail riding or whatever, that
>is way too much oil. A good oil injection system like Yamahas
>can deal with that and give you the 20:1 when you need the oil
>and 80:1 when you don't.
>
>Of course as has been pointed out elsewhere in this thread, if
>the oil pump breaks you get a ratio of 0:1. But I haven't
>seen any Yamaha oil pumps break, they seem to be pretty reliable.
>I suspect that a lot of "oil pump broke" stories were really
>"I forgot to put oil in". :-)
>
>
>Eric
>
Eric,
I think you misinterpreted what I was trying to say.
It isn't usually the oil pump that breaks, but rather the throttle
cable from the "Y" to the oil pump.
The throttle cable from the twist grip goes under the tank, and into
a junction (Y), where it pulls on two cables. One of these two cables
goes to the carburetor, and one goes to the oil pump.
I learned to check this in '77, when the cable from the Y to the
oil pump broke on my TY250. I had to rebuild the crank, because the
pump was only oiling at an "idle" rate.
After that experience, I would always check the cables by twisting
the throttle and holding my other hand against the housing of the oil
pump cable, to feel if it flexed as I twisted the grip.
I try to take advantage of the expensive lessons. <G>
Jim
MX Tuner
spewed forth:
> I learned to check this in '77, when the cable from the Y to the
>oil pump broke on my TY250. I had to rebuild the crank, because the
>pump was only oiling at an "idle" rate.
I believe (this means I may be mistaken here) that the autolube system
also used the engine rpms to deliver more oil also. Higher rpms gave
more oil regardless of throttle opening.
MX Tuner
Tim Richter
wrote:
Right-O
Glen
running too hot of plugs on highways. Never have had a problem with
autolybe system. Riding buddies of mine with a DT175 and a DT250 have never
had problems except when the line to the carb from the injector came off
once. For 25 year old bikes that still run (used on forest trails and sand
pits) I would say pretty reliable.
Glen
"Thomas Potter" <tho...@hevanet.com> wrote in message
news:utgnl58...@corp.supernews.com...
> 'If it aint broke don't fix it'.
>
> There can be alot of convenience in the autolube.
>
>
>
>
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the kicker. The drain for it is on the bottom of the engine, fairly central. Probably a 17 or 19mm hex bolt. Drain from there and put back in the amount cast into the clutch cover, just above the filler. As long as it's not leaking, you don't need to change it very often, once or twice a year depending on how much you ride it.
Go fast. Take chances.
Mike S.