EFI cold weather facts

<div class="FTQUOTE"><begin quote>Can an EFI ATV always start in sub-zero temperatures? No. Most EFI quads have a below-zero temperature threshold. Some are claimed to operate in conditions as low as -40 F or lower. Sure, the EFI will be less susceptible to cold-weather riding problems than a carb, but cold-weather cranking and starting also depends on the quad's battery. Both the Suzuki and Yamaha are electric start and rely on their traditional batteries to fire up. EFI or not, those in the "winter zone" should invest in a battery charger. </end quote></div>

EFI or not that thick cold syrup oil has to be warmed up before you ride EFI or not.

Another fact.

<div class="FTQUOTE"><begin quote>Can an ATV with EFI perform flawlessly at any elevation? No. Yamaha says its Raptor 700R will offer optimum performance from 600 feet below sea level to 15,000 feet above sea level. But, Yamaha engineers say at higher elevations, an EFI-equipped ATV will more than likely lose horsepower, but should retain the same throttle response. Either way, an EFI system should save tuning time compared to an engine with a carb. </end quote></div>

 

<div class="FTQUOTE"><begin quote>Originally posted by: Wayne36

<div class="FTQUOTE"><begin quote>Originally posted by: Gimpster



Sounds like a tight valve issue or a stickey IACV.



I have been chasing cold weather start issues on these 420's.



Temps have dropped again so I can resume tests



Too bad your dealer never took a 60 second snapshot of the system and could send me the file. I would like to look at it







----- Gregg -----</end quote></div>



Hi Gregg,



Just curious by what you meant when saying "I have been chasing cold weather start issues on these 420's?" Does there appear to be a problem with these models, or by "chasing" are you trying to discover if they do for curiousity sake?

Thanks</end quote></div>

Yes, "chasing" is that I am looking for a solution. I have had numerous calls of no start conditions in tempuratures where most people stay in doors. Near or below 0 degrees farenheit.

----- Gregg -----

 

Gimpster, wasn't there a TSB or reflash or something for Rincons with that issue?

 

I will have to manually search my paper bulletins filed in my tool chest.
I have torn the Interactive network apart looking for a clue, coming up empty.
Some units I sat outside for 6 hours during the day in 15 degree temps have started no problem
One I left set overnight did not start in the morning when it was -4. I pulled the temp sensor wire to set it in default in case it was out ranging itself left me frozen and no cure. Had to go on with my day from there. Later I pulled the IACV and found moisture in it. Haven't had time to follow up since.
I need to set 2 units out overnight and run seperate checks on them, one being installing a warm IACV in a cold unit before trying the initial start.
Honda says they should start the way they are set up at these temps, and have not come up with any other suggestions.
Too bad the HDS will not take a snapshot in the morning when I am cranking them over. Looses communication line.
Oh well, another day at work

----- Gimp -----

 

Sounds like a problem with a lot of Hondas. I have a 2006 Rubicon that refuses to start in the really cold stuff - at least it did last year.

 

Have you used the primer on the side of the carb ?
We have had no issues with Rubicons once the primer is used or after we adjusted the carb correctly

----- Gimpster -----

 

In carb quads of any brand I've found that even moderately stale gas hinders cold starting.

In addition to using the primer bulb like Gimpster said, you might also turn the gas off and run the float dry before parking the quad, or alternately opening the drain in the float bowl before attempting to start.

Also, I believe your Rubicon has an electric carb heater, so I'm guessing it might not hurt to turn the key on while you set the choke and hit the primer, so that it has a few seconds to get warm.

Lastly, if you are talking serious below zero numbers, be sure to switch to oil of appropriate weight.

 

Thank you, that was a good post JeffinTD...

Gimpster

 

Thanks guys! Unfortunately, last winter, I had to learn all of that the hard way and was forced to read my owner's manual from front to back. It was then that I learned about the primer pump on the carb. The conditions under which I tried starting the Rubicon last winter were kind of unusual, however. The temperature was hovering around 0 degress F and it was snowing. Dad uses the Rubi to plow his driveway and was pissed when it wouldn't start for him that day. When I drove to his house to try to get it started, I did use the primer pump but to no avail. It ended up sitting there until the next day when it was a little warmer. Fortunately, he has a snow blower and used it to clean off his driveway.

One other thing Gimpster.. My local Honda dealer recommends that I always run 10w-40 in the Rubicon which seems a little suspicious to me. Is he on crack? Is there any reason why he'd tell me this? I was thinking of switching to the Amsoil 0w-40 blend for ATVs (for wet clutches of course).

 

10W is 10W no matter what number comes after it. 0W would be better for cold weather starts. A syn oil would be better yet. Dealers are knowledgable about a lot of things concerning your bike, but they are not God and can not preach what oil or filters you use. This all goes back to the fair trade act. If they tell you that you have to use their oil or their filters, (whether better or not ) they must furnish them to you at no charge and can not void warrentees if you do not use their certain maintance products.