A friend of mine has a newer sportsman 800efi and his friend a rzr with efi. When it is very cold out say in single digits there machines will not start. He thinks it has something to do with the efi? I have a 500hoefi and never a prob starting in cold weather. I was thinking maybe there fuel pumps were getting weak

 

I'd check the battery. If thats the original battery in a 2010 model machine, its most likely used up. A weak battery will start an atv or utv when its warm but many times won't when the temperature is much colder. Most efi machines require a fully or nearly fully charged battery to start them. That's what I would look at first. That's going to be the easiest thing to check and the easiest and least expensive thing to replace.

 

Makes sense. Thx

 

Not so much voltage as amperage can drop in cold weather starts.Even with battery tenders,etc,several posts on the Rzr and larger bore machines having problem in single digit temps. If you have enough patience look at this experts explanation on voltage and amperage. Plus forgot to show what these folks said. "Cold weather is especially hard on car batteries. According to AAA’s Automotive Research Center, at 0°F, a car’s battery loses about 60 percent of its strength and at 32°F it loses 35 percent. During cold temperatures starting an engine can take up to twice as much current as needed under normal conditions. It is advisable to have your battery tested, as well as your starting and charging systems prior to the deep cold of winter."

 

If batteries are OEM they're most likely the culprits in my mind. It'd be one thing if they wouldn't start when they were brand new, in cold weather. If it's just recently I'd look at the batteries too.

 

I know it seems like most people automatically jump the gun and think its something really big, but alot of the times its actually just an easy fix like a Battery. Not to say i havnt thought the worst before either!!!

 

That's exactly what these are for. Can check if battery voltage and amperage is up to snuff,whether it has has a collapsed(dead) cell, if it's getting weak when placed under a load,plus can check if charging is good or bad. For 20 bucks in a lot of places now this is something that everyone needs in their tool boxes. Can save a lot of tail chasing and second guessing.