I recently bought a 2006 arctic cat 400 4x4 manual shift ATV. I noticed that the mph and odometer seemed a bit off, so I tested it following my truck a few times, and sure enough it is almost 10% off. These new units have a fancy electronic odometer and switch for rpm/mph, too bad they dont work right! My '98 has a simple analog spedo/odometer and it works great, accurate as can be.

Is there any adjustment for this? Would the tire size make any difference on this? *(I noticed that the new 500 machines have larger tires). Anyone else notice this (or care) ?

thanks in advance for your input.

 

Ace,
10%...consider yourself lucky. The odometer on my '06 650 V2 is slightly less than 20% off (+). The speedo I can live with, it's only off by about 2-3 MPH (+). Both have been GPS checked. 20% is so far off as to make the odometer and trip odometers unusable.

According to my dealer there is no adjustment. He called AC and got the "deer in the headlights" answer. I called them and have yet to receive a return call. I am a reasonable person and do not expect perfection, but I am also VERY persistent.

Yes, tires will make a difference and in your case, 10% (+ or - ?, you didn't say) is probably correctable, although 10% isn't too bad actually. However, that said, with a 400 and - assuming your odometer is plus off - going to a significantly larger tire IOT correct the error will have a major impact on performance.

As I said, I don't expect my odometer to be perfect, but clearly there is a calibration issue needing corrective action

Here's another one. Does your RPM return to normal after a ride? I mean the instrument, NOT the the engine. When first started, my RPM on the gauge appears to be accurate. After a ride the gauge will remain around 2000 RPM although the engine is clearly idling at a normal, 1000-1200 RPM. It's almost like it's hanging up, but bliping the throttle will not correct the inaccuracy.

At first blush, this new instrument pod appears to be a great thing. Its excution, however, is lacking.

Gamer

 

I had the same response from Arctic cat. My dealer told me there is nothing they can do. When I called corporate I got dumped into a phone mail system and have not heard back. So much for a guarantee.

Actually, my odo seems to be 7.5% UNDER the actual milage (at least from 3-4 test runs) consistently. So for a 10 mile trip it shows 9.2. I know this is 'close' but these things are expensive, and I know when this computer or whatever is in it fries out, it will be a costly replacement that I likely cannot do myself. Plus when I'm stuck out in the woods due to a computer glitch I will certainly be pissed off that I didnt just look for a 98-2001 used model. There are a lot of things I DONT like on my new machine, and a few features that I really like (like higher clearance, 4wd, low range). But I use my odometer heavily for training dogs, and being off 10% can matter quite a bit.

BTW... GPS milages are often suspect (by 10-30%) especially in hilly forested areas. Check it with a reliable odometer and see for sure

What impact do larger/smaller tires have on performance? The tires on mine seem too small for how heavy and high up the bike is.

I have not checked the RPM readings, but I'll look at that more closely over the next few rides. Thanks for the reply.

 

...I know when this computer or whatever is in it fries out, it will be a costly replacement that I likely cannot do myself. Plus when I'm stuck out in the woods due to a computer glitch...

You don't have to worry about being stuck in the woods. The computer head is a different animal from the CDI unit that fires the engine.

...I use my odometer heavily for training dogs, and being off 10% can matter quite a bit...

If you need an odometer that is "right on" for your dogs, no quad odometer is that accurate unless by luck. Heck, up until a few years ago the mfgr's never even installed speedometers. A few days ago on e-bay I ran across a universal add on unit for speed and distance that in theory should be very accurate. It was listed under e-bay motors, ATV, Arctic Cat Parts. What caught my attention was that you had to measure your tire diameter to the nearest mm to calibrate the unit. Other than that I know nothing about the unit, whether it works as advertised or not, or cost.

BTW... GPS milages are often suspect (by 10-30%) especially in hilly forested areas. Check it with a reliable odometer and see for sure

Prior to retirement I used to teach satellites, mostly classified, including the GPS satellite grid. The errors you are talking about are "slant range." Meaning hills are slant range, not horizonal distance. Still they will be a whole lot more accurate than most odometers - overall, and VERY accurate over level, or almost level ground. BTW, did you know the positional accuracy AVERAGES 179 feet for ALL GPS'.

...What impact do larger/smaller tires have on performance?...

Think of it this way and just so it is easier to understand, intuatively you already know this. Suppose you were able to put 10 foot diameter tires on your quad. How easy do you think it would be for that 400cc engine to pull those tires. That's what I mean by affecting performance. The same thing applies - to an obvious lessor extent - when you go from your current size a larger size. Outside diameter I mean, not rim size. It's harder to pull those larger tires. ...and, because a larger tire goes around fewer times to cover the same distance, the speedometer will read less because there are fewer pulses from the speed sensor. In your case, since your odometer is reading LESS, you need more impulses to correct the inaccuracy, or SMALLER tires. I know you don't want to do that since you made mention that the existing tires are a little small for the machine.

I'm sure there is an easy way to calibrate these units, but they are sealed and probably quite expensive, and I'm no electronics person. I do intend to stay after them about it, howver.

 

Thanks for the reply information. I actually got a callback from someone at Arctic cat yesterday evening and they said they would try to work with our dealer to see if anything could be done. I wont hold my breath, but at least they called.

Interesting about the sattellites. My only real experience was in a race up here where the advertised second leg distance was 27 miles (as reported by trail groomers using GPS units). The actual milage turned out to be 44-45. I"m sure acuracy varies by unit.

Makes sense on the tires. .

 

The only easy adjustment is tire size and that's not cheap. Did AC change tire brands between '05 and '06? My '05 400 is only off a couple of mph at 50 mph. Otherwise not enough to worry about. But I do know different tire brands will have different diameters in the same tire size. Just a thought, how much air pressure are you running, that could make some difference, I doubt 20%, but maybe up to 5% as a softer tire will flex more making the diameter shrink.

 

Bear,
I certainly aware of the tire issue. My father owned his own tire business and I've been involved for, well, lets just say I'm older than you (you old fart), a long time.

I think tires could be adjusted within reason, either by size or inflation, to compensate for a few MPH, but it will be very difficult to do 10% odometer reading in Andy's case, particularly since his odometer reads UNDER and he would have to go to smaller tires to correct the error.

Then another issue would be the speedometer. It seems that the errors are not related, meaning 10% odometer does not necessarily equate to 10% a speedometer error. Correcting one could very well adversely affect the the other.

As I said, I don't expect perfection, but in today's world a reasonable expectation should be <3% odometer and 1 1/2 MPH for the speedometer. It's called homework and my sense is AC wasn't as digilent in this during development as they could and should have been. I mean, they outsource the speedo head and the mfgr is only making it to AC specs. ...but, what the hell do I know, I'm just a old fart myself.

 

First off I agree with Gamer. There are several ways this speedo could work. A pulse count generated in the sender and counted by the speedo head, in which case there is no way to adjust it. But if it is just a voltage generator, then an adjustable resisitor spliced into the input to the wire to the speedo head, would give you some adjustment. If the electronics in the control head is designed properly, there would be an adjustment built in as the tolerance in todays electronics there should be one. However accountants rule out these kind of common sense things because they would cost 5 cents.

 

Well, upon further investigation I find that the speedo is a pulse system. So the resistor thing won't work. The speedo system on the tranny is the same as last year, so I'm betting that the gear ratio change is what is causing the problem, they need to recalibrate the speedo head.

 

Bear,
At first blush I thought, yeah, Bear's is exactly right. Gear change = new calibration requirement. But the more I thought about it, I question that theory. The reason is Andy's odometer is off minus (-) by 7.5%, and mine is plus (+) by slightly less than 20%. Unless of course there is that much slop in mfgr tolerance. I certainly hope not. In a bigger sense it really doesn't matter. There is a problem and needs to be fixed.

You're right about one thing, it's probably some bean counters input. As I said, I'm not an electronic person, but it doesn't seem too difficult to me to have some sort of adjustment on the speedo head to compensate for unit variance. After all it's all done with electrons within the head unit. Another thing occured to me. Do you suppose the electrical stability of the bike could be an issue? IOW, if system voltage was a little high (or low) could it throw the reading at the head off, therefore giving a higher or lower reading?

Anyway, I got in contact w/AC this AM and they were nice about it. One of their techs is going to call my dealer (the dealer called AC a couple of weeks ago). I called the dealer after I talked to AC and alerted him to the incoming call. Compounding my problem is the fact I'm leaving here on Sunday and won't be back until next May...and the dealership is being sold and will transfer to the new owners w/in the next week. ...a personal problem I know.