I've got a '06 Predator 90 that has had the first pre-mixed tank run through and is now on second tank of straight 90 octane. Even though it's stored inside, the warm up is very sluggish. It requires a choke to start and then slowly let off choke while maintaining throttle. After 30 seconds of medium reving and then put in gear, it is very sluggish and sometimes stalls out. Once you can get it moving with choke off and get a minute or so on it, it's fine. Warm up should not be that bad in those conditions. Any ideas? It's certaintly not a rotax 2-stroke ;-)

 

What temperature are we talking ?...It might need a little tweaking of the air screw on the carb..

 

A minute or two warm up time does not sound bad on a carb engine.

Todays fuel injected/computer controlled engines have us spoiled. I remember many a days growing up sputtering along in cars/trucks of old waiting several blocks/minutes for it to warm up.

Higher octane fuels can also lead to hard start conditions in cold weather. Remember higher octane just means the fuels ability to resist burning, which also means in a cold low compression engine it can lead to a hard start condition.

 

Garage is kept at 70 degrees and outside temp is has been about 50 on average. It's started in the garage, so it's pretty warm to start with.

 

I've had many carb 2-strokes in the same conditions that do not exhibit this problem. I hear you on the fuel injection, but all of my machines still live in the world of carbs :-)

 

What does straight 90 octane mean? You have the auto oil injection hooked up right?

 

"straight 90 octane" means no oil pre-mixed into the fuel.....it's using the oil injection only.

 

I'd have to agree with oldyeller. My daughter's 90 doesn't have problems idling once it has been started. Usually when the quad has a hard time idling, the first thing you want to do is try adjusting the air screw.

 

I'll give the air screw a try tonight.

 

Well, last night when I started it, it ran fine this time. Did bump up the screw a tad and will try it some more over the next couple days.