A group of us that I ride with are heading down to the Rocky Mountain ATV Jamboree in Sept. and we are wondering if we could just install a K+N filter instead of rejetting our quads. I know you are suppose to rejet with a K+N filter are your normal altitude but since we will be ridding in thinner air wouldn't that even out for us ? Any thoughts would be welcomed Thanks Kevin
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I have done a few posts on this before. My Rancher has a K&N and MegaMax II pipe, and is jetted for aproximately 1,000 ft where I live in the valley. A typical mountain ride for me will cover extremes of altitude, so no one jetting can work. Rides starts at 4,000 ft and can go up to over 10,000 ft.

I have installed two TPI VALVES (www.thunderproducts.com) in the airbox lid. These have a sliding opening that you can move to increase or decrease your air intake. As I ascend in altitude, I begin adding air to compensate. Above 10,000 ft, I just remove the airbox lid completely. You have to get use to it and play with it a little, but the system works well!! And when you return home, you are still properly jetted for that altitude. But, be sure to close the valves again as you descend, or you will end up running lean (bad for your engine).

Believe it or not, I did once try the switch from a stock filter to a K&N without rejetting (you can tell I am a desperate man!), and it was to imprecise to work well. On the Rancher, the limiting factor for airflow is the snorkle opening size anyway!!!! Without venting the airbox lid, there is no other way to get more air in there!!!

Another nice thing about the TPI VALVE, is that when you have to do a water crossing, you can just shut the valve. I would not however do water deep enough to cover the top of the airbox, because the valves are not completely water tight . If this is an issue, just carry an extra airbox lid that isn't vented for when you want to go swimming.

 

Thanks for the imput. Since this might only be a 1 time ride for me I'm not sure if I want to have to rejet or not. The valves in the air box lid sound like a pretty good idea. Thanks Kevin[img]i/expressions/face-icon-small-smile.gif[/img]

 

I have a 2002 Rancher 4x4 which I am just on my second summer with. Lack of riding partners have limited me on trips.....Want to go riding in CO...let me know. I use it for hunting and would like to do more joy riding. I hunt in KS and in the Rockies around 10,000 ft. I normally joy ride in the foot hills at around 7,000 ft. This past weekend I was on top of the rockies riding at an average of 12,000ft, topping out at nearly 13,000 ft according to my GPS. The ride was full of challanging mountian climbs that were awesome. However my poor machine would have liked to have choked to death.

I have never srewed with the jetting as I don't know much about it. Found that TPI product to be interesting but had some questions. Going to need to do something next time I am up there! Was planning on rejetting....but with my variations of altitude I am concerned about constantly being to rich or to lean. Some questions.

#1. Even with the TPI product....do you find that a lack or air is just simply that and even running wide open there is just not enough air? On the other hand I realize that if you cover your mouth at 12,000ft and then uncover it for less restriction you are better off.......Thoughts with respect to carb and this TCI product at say 12,500ft?

#2. Does the TPI have any air filtration? They talk about internal so I am assuming no and that it is left up to your ATVs filter and is just a cover replacement. Correct? Then you mentioned installing two.. I see where you own multiple machines. Guessing you meant another on one of them. But then thought, well maybe he is doing something in parallel for some reason. You did not install one on top of the other did you?

O ya...there were water crossing all over the place were I was at this last weekend. However they were just at mid wheel.

Any suggestions would be greatly appreciated!

 

cj-What is the elevation at Parker?? Most of Colorado (even the flat land) is moderately high. Honda jets for sea level at the factory, so if your dealer didn't rejet for your base altitude, you are riding a sea level bike!!

First of all, I would get a K&N with outerwears. The stock filter insert is pretty restrictive, so that and your snorkle will limit the amount of air you can get into the engine. Also, consider an aftermarket muffler. And then rejet for your base altitude. The more power you have to start with, the more you will have left when the altitude steals it!

First, I run 2 TPI valves side-by-side on the lid of each Rancher. When it gets real bad (above 10,000 ft) I just pull the lid off completely, and it is a whole new machine!!

The TPI does have a filter in it. It is course, but still helps. Plus, it is on the top of the airbox under the seat. Utiltiy bikes have big fenders that keep the dust pretty much under the bike (unlike a sport bike!), so this is a location that stays pretty clean. I rode all this weekend at high altitude (~9,000 ft) behind my son, eating dust all the way. With the TPI's each about 1/2 open, the filters are not noticeably dirty.

The TPI's are no magic fix. They primarily help top end power, but not quite so much on the bottom end. But they are a good solution for those who ride a variety of altitudes in a short period of time.

And as for riding solo, I do it all the time!! Not many people have the patience to go with me and spend a weekend rock-crawling up old mining roads, so I just go and do it anyway. I always give somebody my route, and I check in before, after, and during the ride (get a sat phone if you need to). If I dont' check in, they will know aprox. where to find me. It's really no big deal!!!

 

Recon, Thanks for the info! Parker is is some were around 5900 ft. I am a former Jet Ski Junki and they "jet jet skis"...sounds funny.... at the dealer here. This is my first land roving toy I bought and figured they jetted those for us highlanders also. Guess not. Will remember that next time!

I am going to go with all your suggestions. Sounds like you have really researched it out and have the same climbing and mountain exploring type of riding style. I have the Rancher 4x4 plain jane (non ES).
I think it is an excellent choice for high mountain climbing with the weight to power ratio. I have had many compliments on it from others who had much heavier machines or smaller under powered machines. I am also know to load it to the max weight carrying capability on both front and back racks and it is like a pack mule. Maybe only thing missing is independent rear suspension.

See where you are a sport ATVer also. I am looking into purchase of one.... any suggestions? So many new options these days. Probably going to avoid the overly heavy large bore 4 strokes. Just seems like to much weight and over kill on power which would could be a dangerous thing for me. Looking at the 350 to 400cc 4 strokes of all manufactures. Artic Cat and Polaris have some interesting new options. Anyway would be fun to enjoy both worlds,....."the vertical climbing and no getting stuck" 4x4 class.....and the "whip it around the track fast" class.

 

5,900 ft is real high with no rejet! Check with your dealer. I would think that is something they would automatically do to every bike they sell?????

I have ridden every bike out there (except the new YFZ 450 unfortunately!!), and I can highly recommend the Z400 as the BEST ALL AROUND bike. I am hoping for a Honda with the XR650 engine this fall for desert riding, but who knows. I'm not sure an MX bred 450 will do it out in the open desert, but hey, 250R's are still winning big desert races.

We have the best of both worlds! Ride the sport bikes in the desert during the cool months, and the utilities in the high mountains during the hot months. Oh yeah, I have ITP ATR's on the Ranchers (on light aluminum 12X7" rims). The ride is real nice!

 

I wish the dealers would automatically re-jet for this altitude, but most do not. When I bought my 700 the salesman repeatedly assured me that it was jetted for this altitude...wrong, still jetted for sea level.[img]i/expressions/face-icon-small-disgusted.gif[/img] I have my bikes jetted for 6 - 9000 feet. It does fairly well around here and in the mountains.