2004 Arctic Cat 400 very hard start random dies

[Chad Dickerson]

I am goin nuts here! I have a 04 400 air cooled 4x4 , I'm a atv,car,truck,mower mechanic for yrs,just sayin. Ok it cranks and kinda fires now and again then after 5 min of cranking and stopping itl start if u touch throttle itl did then u start all over! If u let it warm up sumtimes u can throttle it up other times it just does! Just depends on it? When it stays running it runs awesome,no problems except it just does randomly like u shut key off? Sumtimes itl start right back up others itl do the no start thing! IV put new plug,adjusted valves and hot tanked carb? I'm at a loss here guys! Please any other ideas? I don't think it's anything to do with flywheel? It's not the auto it has a hi low reverse lever on left fender and foot shifter? Help please lol

[Frank Angerano]

I would do a compression test.  See where your at for starters. Maybe a leaking head gasket, rings etc. 

Second I would check the intake boot that connects the carb to the engine for cracks. Then look at the quality of the spark and make sure it’s strong and that it’s not breaking down after it gets warm.   

And just a dumb question, have you checked the fuel that it’s not bad and you have a good flow going to the carburetor?

[Chad Dickerson]

It only has 400 miles on it, it was rode very little but started and kept up by atv shop , then new owner got it ,he was using it everyday for bout 6 months then this started one day while riding. I'm sure compression is like new but I'll check for sure in morn. , I looked at carb to head intake boot and it's in great cond. He was using it alot and uses seafoam every other tank but I did clean carb just cuz.i have looked at spark when tryin to start and it's a white blue hot, changed plug anyway, and when it does itl start right back up. Most times its just that sumtimes even after warm itl start up but if u touch throttle itl just die, only sumtimes? Itl idle for a long time then just die? It's crazy now I'm going crazy! 

[Frank Angerano]

Lol take a deep breath.  There is an answer and it’s just going to be a process of elimination. You have to go over things again to be sure. I know it sounds repetitive but it’s worth it.  

What did you set the air fuel screw at ? 

Check that the choke is working and opening and closing properly and not getting drawn closed as you rev the engine.

Look through the wire harness to see if any rubbing against the frame is happening where wires are intermittently hitting the frame, take the plugs apart on the harness and add dialectical grease on the plugs and put back together. 

 

[Chad Dickerson]

Feul screw is at 2 turns out, choke or enrichener is working properly, I will go over wording tomorrow and report findings. Thanks for helping it's drove me nuts for 3 days now and I have to get it finished just never ran into this before. Thank u

[mikeexplorer]

One thing to try is while it is idling, turn on your headlights low and high beam then try to give it some throttle. If it runs better, shut off the lights and take a meter and measure the voltage on the battery. Should not be above 14.5, if you give it throttle and it rises, the regulator is not working and it will mess up the CDI and cause a loss of spark. It is also possible the voltage goes low and will cause loss of spark. A bad regulator will cause these issues as well. Its an easy test with a meter.

Though the symptoms are acting like the carb is not cleaned properly. You could also have some junk in the tank from it sitting and it got sucked into the carb.

Older cats fuel lines were also not made to handle the E10 gas that we use nowadays, the inside of the fuel line could be breaking down and causing junk to be sucked into the carb. With a machine that is now 15 years old, I would replace the fuel line, then add an inline fuel filter while your at it.

Wire rub through was not known to be an issue with 2004 cats, and with only 400 miles I would think that is not likely at this point.

Mike

 

[Chad Dickerson]

Thank u Mike I'll try that as well. Really really appreciate your help and the rest of the ideas to try from others! Thank u will post results this morn 

[Chad Dickerson]

Ok I found a prob, I took plug wire cap off to check fire, it fires bout five times then stops fireing for several crañks then fired again for a bit then stops? Over and over? That's why itl act like it's gonna start then not? Any ideas? 

[mikeexplorer]

Check the battery as I mentioned above to make sure its not weak, that will cause loss of spark. The coil could also be weak, that is an inexpensive part to replace.

Have you downloaded the service manual for the machine and schematics?

Mike

 

[Chad Dickerson]

I can't. Find a manual for it to download free? I'll check batt today thank u very much sir.

[mikeexplorer]

Schematics are here, its the file that is large

https://www.mymowerparts.com/pdf/Arctic-Cat-ATV-Repair-and-Service-Manuals/

Service manuals are here:

 

https://support.countrycat.com/?home_feed=feed&order_by=recent&taxonomy_59981_taxa=6bb2d2a2-7689-4e31-9050-ea99c2aac3f0

 

 

[Camaroguy1995]

Did anyone ever figure this out?? I have the same issue. I need to figure it out. Only 710 miles on this 2004 arctic cat 400 4x4

[Camaroguy1995]

On 6/19/2019 at 6:49 AM, Chad Dickerson said:

I can't. Find a manual for it to download free? I'll check batt today thank u very much sir.

Chad Dickerson did you figure this out?

[mikeexplorer]

Post is over three years old, doubt he is going to reply back

 

[Cj Winds]

Please check the magnets on the flywheel, if magnets are loose than replace flywheel. This is a very common problem on the suzuki 400 motor

[Curtis Underwood]

With a firing problem that is difficult to find, you will need a good meter and the electrical prints even if you have to buy them. The problem with trouble shooting without prints is you either have to follow the suspected wires from one point to another so you will know what connectors it goes thru, switches it goes to, and  componets it hooks to and these wires are bundled with other wires of the same or close colors. A print will indicate connector, switches and other comonets such as cdi and coil.The problem is the cdi is powered from the ignition portion of the stator
The first thing I check is the CDI voltages and cdi kill volatge which is only grounded in kill mode. If any of these are intermittent  during this misfiring then you have to trace it back to where your losing the connection. It will be either the cdi unit, safety switches, on/off switch on handle bar, Main switch or wiring connectors causing issues like this to happen.
Here is a not so good diagram of a 2004 400 articat. So as you can see this is a complex wiring system that without a correct wiring diagram it is next to impossible to troubleshoot. The firing is controled by the CDI but the Cdi gets it signals from the stator, sensors thruogh switches ets. You might print this out and have a better view of it.

 

[skills4lou]

AC 400 motor is actually made by Suzuki. It's a great motor EXCEPT for the OEM flywheel. The bonding they used to attache the magnets to the flywheel did NOT last. It's an easy fix, just have to remove the left side of the engine to access. The replacement flywheel uses a different method to attach/capture the magnets and solves the problem.

I happen to have the flywheel removal tool.