I don't understand what you are trying to say Blue Leader. By removing the oil injection you must or re-jet your carb because it is impossible to keep the mixture that you had with the oil pump. More oil = less gas in some throttle ranges, so you have to make the change accordingly. Say you go from a 30:1 mixture to a 40:1 mixture you have to jet down because you will richen up the carb and opposite for going from a 40:1 mixture to 30:1 mixture. Since the pump delivers oil at a rate different according to throttle position, you will have rich or lean spots in your jetting.

 

There are a few reasons to remove an oil pump , and few reasons to keep it on . Here are my opinions :

On 400 Polarises the oil pumps rarely fail , I can recall maybe one that failed , many times when a motor goes south the oil injector gets the blame . In reality , it is a reliable system for metering oil .

The problem with oil injection on these machines comes after one modifies the engine . When you port and pipe a 400 they get very fuel thirsty . With the amount of gasoline going into these engines is best to have lubricant in it rather than depending on the oil to mix inside the engine . The fuel can have a *washing effect * on the injected oil . If you run a ported and piped motor on injection , you may see seizures on the intake . I have been down this road before , believe me , I would love nothing better than to avoid mixing oil in gas , but a 55 horse and up 400 needs premix to insure proper lubrication .

I believe these statements to be true :

1. The oil injection systems rarely fail . Still though , injected oil may not be adequatte on high output engines .

2. Modified engines need a lot of fuel , in this situation where big jets are employed , it is best to have oil already in the fuel .

3. Pre mixed fuel is thicker than regular fuel . It will require richer carburetor settings , but , it isn't that big of a deal .

4. The only bad oils I have seen seperate from the fuel . I use Klotz at 32 to 1 . I know it will stay mixed most anywhere I send it . 40 to 1 , thats fine too , the main thing is you have oil in the gas and it stays suspended .


Rick Ritter

 

NCScrambler,
like you said, with the injector system, you add more oil as you twist the throttle because you need to compensate for adding more fuel. This keeps the ratio constant. If you pre-mix it, your ratio is precise and your carb dictates how much fuel and air is delivered.

All manufactures indicate a prefered pre-mix fuel/oil ratio. Too much oil and you will foul plugs and not enough you lose lubrication and become lean.

As I said before, you adjust the air/fuel ratio entering the combustion chamber by changing the fuel circuits in your carb (jetting). You have the pilot jet, pilot air screw, throttle slide, needle jet, air jet, and main jet. Each for their corresponding throttle position.

You can fine tune or fix minor problems by adjusting the pre-mix. I do this for slight altitude, temp, and load conditions. It changes the jetting from bottom to top equally. which is nice.

Gregs bike was lean via the jetting or oil injector.

 

Hey Greg V. HPD sells the block off for 16.00 and the replacement cable for 24.95. I just bought both and am waiting for it to come in. I would suggest getting it since you have the exterminator kit. Hope all works out.

 

I removed my oil injection years ago and I've never had a problem with plug fouling. In fact I think I fouled more plugs when I had the oil injection in place.
It might be a slight inconvenience to mix your own but I like the piece of mind knowing the oil is in there.

 

GregV,

One reason I eliminated my oil injection is we ride in lots of water. If any water ever gets in the oil reservoir, your motor will be toast. Also, if you ride through much brush, one of the oil lines could get knocked off. I have heard of both things happening..........water in the oil, and oil line getting knocked off. The cons to removing the oil injection is that you will go through more oil, and have to always premix. I like HPD and their products, but I could not get their oil injector block-off kit to seal off good. I ended up getting the hot seat unit which is a different design and it sealed off fine.

Waylan

 

I agree with you Blue Leader, I was just not understanding what you were saying the way you were saying it. [img]i/expressions/face-icon-small-smile.gif[/img] Thanks.

 

I have 7490 miles on my Xplorer, I use the oil injector, and have changed spark plugs once.
I have only heard of one pump failure, I think they are quite reliable.

My reasons for keeping the injector: Convenience - I ride with other guys with 4 cycles, and we all fill up with the same gas can. As long as I have oil in the tank, I am fine. Also, I don't have to mess with the mix.

Precision: I think the oil injector system is better at giving the amount of oil needed at a given throttle position.

Reliability: In my case, I think it might be MORE reliable than premix because I have friends, family (like a 16 year old nephew) that come riding. They sometimes 'help' by fueling up my quads. Imagine if they filled up one that needed premix with straight gas.


Reasons I would switch to premix: Deep mud/water riding. The injector box is at the bottom of the engine. That is one place where moisture can get, and do some damage, without you noticing it until the damage is done. Also, if you ride in water/slush in cold weather, the box can freeze.

Modded engine: I think Rick Ritter explained this very well

Riding buddies: If everyone else used premix, I might switch so we could use the same fuel can in a pinch.

Farmr

 

Here is the scoop. I spent the last few hours at the dealer tearing down our 400 only to find exactly what we all suspected.......a hole in the piston.

BUT.....come to find out, they had put a "BPR" plug in it instead of a "BR". The "P" stands for PROTRUDING. The bottom line is the plug was too long putting it too close to the piston........ = HOLE IN PISTON. I am still going to go up a jet size or two. I am also going to be going .020 over on the new piston because right now there is .012" clearance between a stock bore Wiesco piston and my cylinder after he honed it out today. So, he admitted that it was his mistake and is going to make it right.

I helped him tear it down so I could learn more about how the 2-strokes go together. Oh well, accidents happen, it will be better and faster after everything is put back together again now so all is well.

It did appear that the oil injection was working fine, so I am going to see how things go durring the remaining 5 months of my 6 month warrantee and decide then weather or not to lose the oin injection system.

Thanks for all your advice.

GregV

 

It's not always the most fun way to learn, but often times it sticks with you better. Getting involved is the smartest thing to do. Good luck! [img]i/expressions/face-icon-small-happy.gif[/img]