The predator still has the first tank of break in oil in it. It is runing rich. It keeps fouling out the plugs after about an hour worth of riding. Can someone tell me what the carb adjustments should be? And if there is an adjustment for the oil injector and if I should attemp it myself or take it back to the dealer?

Thanks for the help.

 

For the breakin tank, they sometimes make it richer, by adding oil to the gas, in addition to the injector tank. You could ask the dealer, and he might check it out, but he will probably have you run another tank or two, and see if it still fowls the plugs.
You could go one heat range hotter on the plug, and that will be better at resisting fowling.
Normally, with small kids, and having the restictors in, and stoping the throttle short, all lead to low rpms and loading up.

 

Thanks for the reply. I did take the restrictor of and open up the throttle limiter almos on the first day he rode it. My son is 9 and really rides well. i have about 4 tanks of gas threw it now. I checked the oil and it is about a little more than half way down from full. What plug should I go to?

 

There are many reasons why a plug would foul. Here's a few things that come to mind:

- Running too cold of a Spark Plug. If your plug is too cold, it doesn't build up enough heat to "burn off" the carbon. Over time, the plug gets really black and eventually plugs up with junk.

- The factory Oil Injection system is pumping out a little too much oil. This could be caused from its adjustment being a little "too much" or running extra oil in your gas tank a little long. Hence, more oil then it can burn away.

- Proper mix of oil and proper plug and it still carbons up??? Yes, this sometimes happens when the engine is run at the same LOW RPM for a very long time. From my experience, I found 2 stroke engines need to rev up & down in order to "blow the carbon" out of their system. New drivers with its CDI jumper still connected stops the engine from reving up. Even gas throttles set at 1/2 throttle stop the engine from "reving up". Hence, lower heat within the engine and not enough air flow to blow the carbon out of its system.

Here's a few suggestions that may help:

- For low RPM / low ground speed riding conditions, replace the spark plug with an NGK Plug that has a "P" within its code. This "P" stands for Protruding Tip. Protruding Tip plugs are great for low rev / low air flow 2 stroke engines. Some people call these "city driving" spark plugs.

- Upgrade your plug to the next higher heat rating. If I remember connectly, that's an NGK BRP6HS or NGK BR6HS plug. The lower the number, the higher its heat rating. In the hot summer months or when the engine revs much higher, then convert back down to its factory NGK BR7HS plug.

- In the end, you may have to "tweak" the jets in your carb. The reason is, altitude does make a 2 stroke engine run rich. If your altitude is higher then the factory carb setting (or what your dealer is suppose to set it at for his region), you may have to "teak" its jets. Since your Pred-90 is running under 3/4 throttle, I would try the "P" plug and a NGK BRP6HS for now. When your remove its throttle restrictor and its still fouls plugs, then tweak its carb.

Hope these ideas help as well...

 

by-pass oil injection and go to pre mix. My pred. 90 was doing the same thing. now that I mix my own oil, I havnt had that problem.

 

Thanks for the replys. I turned up the idle just a hair today and it ran fine. It did not foul out the plug. It also would start better not having to hit the gas the start it.

The only thing Im not sure of is the settings for the carb. What should they be set at from the factory? There are 2 screws the air screw and idle. Im not sure what to start at.

Thanks,

 

The carb at the factory is NOT set to perfection. After a dealer confirms the sale of a Pred-90 (or any mini-Quad), he/she is suppose to "set the carb" based on their store location. Some experienced dealers tweak the carbs even more if they know their customer is located at a lower or higher altitude. However... If a dealer is rushed, he/she may NOT set the carb. I read several posts stating that ALL mini-Quads are set with rich carb settings. If a customer brings their mini down to sea level, it won't hurt the engine. If they bring their mini to the high mountains, its richness won't hurt the engine. If the dealer set the carb for a customer located in the high mountain and that customer took a trip to sea level, the carb would run too lean and hence, immediate damage the engine. Thus, more warranty returns / repairs then the mini's head office wants. So, I suspect MOST dealers set the carbs a little rich.

If you want to tweak the carb jetting yourself, you'll need a good diagram. To see a nice picture with its jets clearly marked, surf: - Press Here -

If you are going to adjust the jets yourself, read the following within: - Press Here -
Note: Although this info was written for motocross bikes, its base information does apply to mini-quads. Lots of interesting stuff I didn't know about.

To obtain good pictures on how to read its Spark Plug, surf:
- Press Here -


Hope this helps....

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Yesterday we rode for about 2 hours. About 1 1/2 in to the ride, the predator started backfiring. It did it about 3 times. I did change the plug before we left. I put in the hotter # 6 instead of the 7.

Should i check the setting on the carb? The mixture settings could they be off? If so What are the settings supposed to be? like 1 turn out or 1/2 out? I m not sure.

I dont want to take off the oil linjection just yet. It is brand new and still under warranty but they are closed today its a holiday.

Can anyone help?

Thanks.