My question is mostly pertaining to motorcycles and atvs. I am a two stroke nut and have two stroke Polaris's. I want to trust that two stroke injection pump and the oil injection. But after seeing a couple 400s locking up, unexplainably, I am going to think it was lack of oil. I know it makes me nervous and I sometimes mix a small amount of oil in the gas anyway. Recently, I unhooked the 250 oil pumps and ran the oil feed back into itself thru a T, so it is feeding its self in a continious circut and use premix of 40:1. Am I the only one that is Paranoid? They do have oil warning lights, but these are just low oil tank sensors, and never tell you if oil is actually being pumped into the cylinder, only if your oil level is low in the tank. I heard alot of bad stuff about early Yamahas too and oil injection. What is your opinion?
Does anyone trust the oil injection 100%.
- Thread starter Panzerman
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I dole out 2 stroke Amsoil to a kid I know for his moped and, not scientific of course, the rate @ which he consumes it seems WIDELY variable. Sometimes it is weeks between requests, sometimes days. It was to the point where I just didn't believe the injector was metering the oil properly. Sometimes the exhaust smoked, sometimes not. This was with Amsoil Dominator 2 stroke. So yes, although I have NO experience with 2 strokes, it became a concern of mine also.
Yamaha has a very reliable OJS on there sleds,never any problems here.
i run interceptor.
i run interceptor.
I never trusted them out of paranoia but I haven't seen a failure first hand.
Originally Posted By: tom slick
I never trusted them out of paranoia but I haven't seen a failure first hand.
It is a little freaky one little failure and your engine is toast!
I never trusted them out of paranoia but I haven't seen a failure first hand.
It is a little freaky one little failure and your engine is toast!
I have been a member of a two cycle form for several years and this discussion occasionally comes up. As with Panzerman, I was also curious about the reliability of oil injection pumps on my vintage Yamahas. Accordingly, I conducted a survey to determine the failure rate of fuel injection pumps on old two stroke motorcycles. I was surprised at how few problems were reported. In almost every instance of failure (which was very few), the pump failed due to improper re-assembly after being taken apart.
There were no outright reports of a pump failing otherwise. I'm not saying that the odd pump won't fail on it's own. It's just not likely to happen if it's not messed with.
I must qualify however that the pumps on these old bikes are gear driven, not electric.
I've read reports of electrically operated oil injection pumps on Johnson/Evinrude outboard motors failing on a regular basis. I know a guy who fried his Johnson outboard due to a failed injector pump. Despite the fact that there is a warning light and audible alarm warning that the pump failed, the operator chose to bypass the warnings and continue to use the motor resulting in catastrophic failure.
If it's a gear driven pump, I'd use it with full confidence. If it's electric, I'd definitely bypass it, re-jet the carb(s) and go with pre-mix.
There were no outright reports of a pump failing otherwise. I'm not saying that the odd pump won't fail on it's own. It's just not likely to happen if it's not messed with.
I must qualify however that the pumps on these old bikes are gear driven, not electric.
I've read reports of electrically operated oil injection pumps on Johnson/Evinrude outboard motors failing on a regular basis. I know a guy who fried his Johnson outboard due to a failed injector pump. Despite the fact that there is a warning light and audible alarm warning that the pump failed, the operator chose to bypass the warnings and continue to use the motor resulting in catastrophic failure.
If it's a gear driven pump, I'd use it with full confidence. If it's electric, I'd definitely bypass it, re-jet the carb(s) and go with pre-mix.
A good design on the Yamaha pumps on their 2 stroke sleds IF...you had a failure the pump would go into full flow/out put and the worse you would see would be fouled pugs.
2 weeks ago, I went out on a friends Yamaha jet ski's. The one I was riding seized up. The oil line came off the pump, starving the engine of oil. We were able to re-connect it and get home. With a nice death rattle inside the engine. That was an expensive failure.
Many years ago, my brand new SeaDoo had the exact same problem. It was repaired under warranty and was never right again.
Many years ago, my brand new SeaDoo had the exact same problem. It was repaired under warranty and was never right again.
I know I debated for awhile weather to bypass the oil injection and since, its the kids quads and they dont pay any mind if it smokes or doesnt, I weighed it to be a good idea to just go the premix route, since I know for sure it is getting the oil. I also mix the gas and put pink or orange zip ties on the premixed gas cans, they are told only to fuel out of those cans. Better safe than sorry.
On my Aprilia, I run Klotz Benol in the gas tank and Red Line 2T in the injector tank. The Benol mix is 100:1 and the injector is at factory setting. If the injector failed then I am relying on the Benol castor oil to protect the engine. It runs a little dirty but at least I know the engine will not seize on me.
I've never seen any problems with Yamaha oil pumps over many years...my last Yamaha 2 stroke with a pump was a 1997.They have their own pump,the others use Mikuni....and I've never seen those fail either.I've had a cable break on a Yamaha,and went pre mix(trials bike).Yamaha are the easiest to go premix on,the pump just feeds into the intake.
We have had a dozen different oil injected 2 stroke vehicles over the last ten years.
Polaris, yamaha, etc. Never had an issue.
Polaris, yamaha, etc. Never had an issue.
I have currently three Polaris 400's which you mentioned. Never had any issues with oil delivery. But, as azsynthetic does, I run a mix in my gas tank. Since they all have over 300 hrs on them without a rebuild, all is good. They are stock and I use Mobil Racing 2T. As a side note, I have a Kawasaki 900 (injection) ski with many hundred of hours without a rebuild using the same oil. Mix the gas as well with it.
Can you still get the Mobil 2T, I havent seen that in a long time? Probably better, safe than sorry, I have a Polaris Xplorer 400 and I always ran a 60:1 oil and gas plus the oil injection is still functional on it. They have a much more robust oil pump than the 250s do. I dont mind the extra smoke. 2800 miles, never rebuilt and still runs like a top, can sit for 6 months and fires right up. Best starting atv, I ever had.
Can you still get the Mobil 2T, I havent seen that in a long time? Probably better, safe than sorry, I have a Polaris Xplorer 400 and I always ran a 60:1 oil and gas plus the oil injection is still functional on it. They have a much more robust oil pump than the 250s do. I dont mind the extra smoke. 2800 miles, never rebuilt and still runs like a top, can sit for 6 months and fires right up. Best starting atv, I ever had.
In all my vintage Kaw 2 strokes, I run about 80:1 in the tank with injectors as a little insurance (usually Klotz Supertechniplate). All these motors have slotted rods, so they could run all premix if I wanted. Reason I do this is that I live in a area with lots of long steep grades where the pump at closed throttle is not doing anything but the engine is screaming doing compression braking (this is an old roadracer trick too).
Originally Posted By: BBDartCA
In all my vintage Kaw 2 strokes, I run about 80:1 in the tank with injectors as a little insurance (usually Klotz Supertechniplate). All these motors have slotted rods, so they could run all premix if I wanted. Reason I do this is that I live in a area with lots of long steep grades where the pump at closed throttle is not doing anything but the engine is screaming doing compression braking (this is an old roadracer trick too).
If the throttle is closed how much gas / oil is getting run through the engine?
In all my vintage Kaw 2 strokes, I run about 80:1 in the tank with injectors as a little insurance (usually Klotz Supertechniplate). All these motors have slotted rods, so they could run all premix if I wanted. Reason I do this is that I live in a area with lots of long steep grades where the pump at closed throttle is not doing anything but the engine is screaming doing compression braking (this is an old roadracer trick too).
If the throttle is closed how much gas / oil is getting run through the engine?
I have had several 2 stroke motorcycles a 1967 a 1971 and a 1974 and a 2003 ATV and no problems.
Originally Posted By: Panzerman
Can you still get the Mobil 2T, I havent seen that in a long time?
Nope, I have it all in my garage....
Two years ago I would have answered this with a resounding Yes, I trust them. Goofy as it sounds, both the Honda Spree and the Yamaha Zuma that go camping had both oil pumps fail the same season. Not like you would think though. They both leaked down all the oil in the tank into the engine. The Spree was a mess... over a quart of oil in the engine. That took a while to pump out of the spark plug hole, and it smoked for days. The Zuma wasn't as bad, but only because the tank was near empty. Both pumps were pretty easy to replace, with the Honda being the better of the two. The flywheel had to come off the Zuma with it's Minarelli engine. Both have been scooting as usual now for the past 2 years. I don't like to premix for most things unless it's necessary. Besides being a pain, you really need to rejet because you'll wind up lean due to the oil replacing some of the fuel.
Can you still get the Mobil 2T, I havent seen that in a long time?
Nope, I have it all in my garage....
Two years ago I would have answered this with a resounding Yes, I trust them. Goofy as it sounds, both the Honda Spree and the Yamaha Zuma that go camping had both oil pumps fail the same season. Not like you would think though. They both leaked down all the oil in the tank into the engine. The Spree was a mess... over a quart of oil in the engine. That took a while to pump out of the spark plug hole, and it smoked for days. The Zuma wasn't as bad, but only because the tank was near empty. Both pumps were pretty easy to replace, with the Honda being the better of the two. The flywheel had to come off the Zuma with it's Minarelli engine. Both have been scooting as usual now for the past 2 years. I don't like to premix for most things unless it's necessary. Besides being a pain, you really need to rejet because you'll wind up lean due to the oil replacing some of the fuel.
Originally Posted By: beanoil
Originally Posted By: Panzerman
Can you still get the Mobil 2T, I havent seen that in a long time?
Yes, discontinued around 2007. I have a case but it really stinks (WWI mustard gas caustic smell). Supposedly a real good oil.
Originally Posted By: Panzerman
Can you still get the Mobil 2T, I havent seen that in a long time?
Yes, discontinued around 2007. I have a case but it really stinks (WWI mustard gas caustic smell). Supposedly a real good oil.
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