Interchangable CDIs with 2003 AC 400 4x4 FIS Auto?

6511 Views 18 Replies 4 Participants Last post by Farrix, 4 d ago

roder

Discussion Starter · 11 mo ago

Hello Arctic Chat folks! I'm a hobbyist mechanic and I recently purchased my first ATV - a 2003 AC 400 4x4 FIS Auto.

This AC currently misfires, stalls at idle, and is very sluggish to start. Steps I've taken so far to repair include:

Cleaned fuel tank
Changed fuel filter
Cleaned carb and jets
Adjusted air-fuel mixture
Replaced Spark Plug
Adjusted Valve Clearance
Replaced Stator (w RM Stator)
Replaced Flywheel/Magneto (w/ RM Stator version)
Ohmed out Stator
Confirmed continuity between Stator and CDI
Confirmed continuity between CDI and Ignition Coil
Ohmed out Ignition Coil and Spark Plug Cap

At this point, I believe the CDI maybe faulty.

After an an exhaustive search, I have not found a replacement CDI (AC part 3402-683) that is in stock or less than $1300 USD.

I have contacted https://regulatorrectifier.com about their next repair date, which is 8/10/22. I am concerned that I have not seen any reports back from others on this forum who have had successful CDI repairs.

Therefore, I'm looking for alternatives, and I'm interested in a 2003 Suzuki Eiger 400 CDI (part 32900-38F10) which I found used on eBay for ~$500.

Can anyone please confirm whether these parts (AC 3402-6830 and Suzuki 32900-38F10) are interchangeable?

Thanks in advance!

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Farrix

· #2 · 11 mo ago

I believe they are interchangeable. The problem I had was the Zuki and cat are different shapes and sizes, and I couldn't find a wiring diagram for the Zuki to ensure pin layouts match.
Did you check the diaphragm?
Did you check/adjust your valves?
Is it an auto or manual?
Jets in the correct places on reassembly?
Have you checked the belt?
Checked the pilot mixture screw settings on bottom of carb?
Does your new plug come out white or black?

roder

Discussion Starter · #3 · 10 mo ago

Farrix said:
I believe they are interchangeable. The problem I had was the Zuki and cat are different shapes and sizes, and I couldn't find a wiring diagram for the Zuki to ensure pin layouts match.
Did you check the diaphragm?
Did you check/adjust your valves?
Is it an auto or manual?
Jets in the correct places on reassembly?
Have you checked the belt?
Checked the pilot mixture screw settings on bottom of carb?
Does your new plug come out white or black?

I ended up sending the CDI to https://regulatorrectifier.com. I'll let you all know how it turns out.

Meanwhile, I've essentially rebuilt the carb and jets, diaphragm, and pilot mixture are all good. Spark plug comes out more black than brown, but I'll adjust it again. I've adjusted the valve clearance and the belt looks good. It's an auto.

Reactions: 1

Farrix

· #4 · 10 mo ago

Did you check the timing? Fun thing I just went through, if you bought it used you may not know what's been done.

I did the work myself so I have myself to blame for putting my timing out, but if the previous owner was doing something like I did with the service manual I used they likely made the same mistake.

take off both valve covers, pull the spark plug and take the recoil off so you can turn the engine over by hand, and the flywheel timing plug.

put a long skinny stick/screwdriver down the plug hole till it touches the piston, roll the engine over by hand with a finger on-top of the screwdriver to ensure it doesn't bind/hang-up. Watch the rocker arms, as you turn the engine over make sure neither rocker is moving out of sequence prior to the TDC of the correct stroke.

I did my own timing chain a few months ago, and didn't see the timing marks on the end of the cam-shaft in the black and white service manual that I printed off. My intake valves were opening before the top of the exhaust stroke, exhaust valves were opening before the bottom of the power stroke.

It's just a quick easy visual reference to make sure the previous owner didn't do something you aren't aware of without having to tear the rocker box off and deal with the NASTY gasket maker.

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Farrix

· #5 · 10 mo ago

Farrix said:
Did you check the timing? Fun thing I just went through, if you bought it used you may not know what's been done.

I did the work myself so I have myself to blame for putting my timing out, but if the previous owner was doing something like I did with the service manual I used they likely made the same mistake.

take off both valve covers, pull the spark plug and take the recoil off so you can turn the engine over by hand, and the flywheel timing plug.

put a long skinny stick/screwdriver down the plug hole till it touches the piston, roll the engine over by hand with a finger on-top of the screwdriver to ensure it doesn't bind/hang-up. Watch the rocker arms, as you turn the engine over make sure neither rocker is moving out of sequence prior to the TDC of the correct stroke.

I did my own timing chain a few months ago, and didn't see the timing marks on the end of the cam-shaft in the black and white service manual that I printed off. My intake valves were opening before the top of the exhaust stroke, exhaust valves were opening before the bottom of the power stroke.

It's just a quick easy visual reference to make sure the previous owner didn't do something you aren't aware of without having to tear the rocker box off and deal with the NASTY gasket maker.

I learned i was 22 degrees out of time 1.5 weeks ago. spent since JUNE trying to figure it out. These engines will run with the timing out quite a ways and seem like everything is alright.

Reactions: 1

roder

Discussion Starter · #6 · 9 mo ago

Got the CDI back and everything tested fine.

I think the next steps for me are to check the timing, as @Farrix recommended, as well as test the grounds and the wiring around the kill/start/stop swtiches.

Reactions: 1

Farrix

· #7 · 9 mo ago

@roder any updates?

roder

Discussion Starter · #8 · 9 mo ago

Nope, haven't had a chance to get to it yet.

@Farrix - Do you know of any good resources on how to check the timing?

Also, really appreciate that you checked in! Super kind.

Farrix

· #9 · 9 mo ago

The easy way I found my issue and to get a rough idea what is going on is to pull the fuel tank, the valve covers, spark plug and flywheel plug to see the tdc mark and the recoil cover

Using a long screwdriver/rod down the plug hole to monitor the piston location.
Rotate the engine over over with the birdcage and watch the rocker arms for the valves. If the valves are opening or closing out of sync with the piston tdc and bdc points then you have an idea something is off.

The hard way is to pull the rocker box and inspect cam marks.

A service manual is available on countrycat.com under technical information.

Reactions: 1

roder

Discussion Starter · #10 · 21 d ago

Well, it's be awhile, but I wanted to share an update.

I don't know what I did, beyond what I did, but the AC 400 is running pretty well right now. It really hates getting started, but once the motor is warm, it runs flawlessly so far. If that changes, I'll let ya'll know.

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Tacopashka

· #11 · 19 d ago

Have you tried messing with the throttle position manual screw on the carb? Both bikes I got had the position way out and they didn’t like starting or running. Right now I have both running just by screwing it in all the way and backing off 2 turns.

roder

Discussion Starter · #12 · 9 d ago

Tacopashka said:
Have you tried messing with the throttle position manual screw on the carb? Both bikes I got had the position way out and they didn’t like starting or running. Right now I have both running just by screwing it in all the way and backing off 2 turns.

Oh absolutely - that was my first adjustment I made. I was able to keep the atv running intially by increasing the RPMs of the idle. It worked, but also I really had the RPMs up quite a bit (~2K?) - I had the arctic cat dealer look it over and when adjusted to spec (700rpms, if I recall correctly) it would die.

Tacopashka

· #13 · 9 d ago (Edited)

roder said:
Oh absolutely - that was my first adjustment I made. I was able to keep the atv running intially by increasing the RPMs of the idle. It worked, but also I really had the RPMs up quite a bit (~2K?) - I had the arctic cat dealer look it over and when adjusted to spec (700rpms, if I recall correctly) it would die.

So dealer didn’t give you an ideas as to why this may be happening? Does it have an auto choke?? Mine actually broke off inside and was running in choke mode..maybe yours isn’t “choking” to give it that rich fuel to start initially? But will run okay when warm..

roder

Discussion Starter · #14 · 9 d ago

So dealer didn’t give you an ideas as to why this may be happening?

Not without spending more time at $100/hr :/

Here's what I've done:

www.arcticchat.com

Interchangable CDIs with 2003 AC 400 4x4 FIS Auto?

Hello Arctic Chat folks! I'm a hobbyist mechanic and I recently purchased my first ATV - a 2003 AC 400 4x4 FIS Auto. This AC currently misfires, stalls at idle, and is very sluggish to start. Steps I've taken so far to repair include: Cleaned fuel tank Changed fuel filter Cleaned carb and...

www.arcticchat.com

www.arcticchat.com

What all have you checked and replaced?

Additional, I had the CDI tested and it came back fine.

Mind you, it's running just fine now (once the engine is warm). One of my last posts was a status update for the benefit of the forums. Honestly I think what did it (and this is embarrassing) is that I replaced the coil.

Have you checked auto choke functionality?

I didn't even know the 400 had an autochoke? I know it has a manual choke

Reactions: 1

Tacopashka

· #15 · 9 d ago

roder said:
Not without spending more time at $100/hr :/

Here's what I've done:

Interchangable CDIs with 2003 AC 400 4x4 FIS Auto?

Hello Arctic Chat folks! I'm a hobbyist mechanic and I recently purchased my first ATV - a 2003 AC 400 4x4 FIS Auto. This AC currently misfires, stalls at idle, and is very sluggish to start. Steps I've taken so far to repair include: Cleaned fuel tank Changed fuel filter Cleaned carb and...

www.arcticchat.com

Additional, I had the CDI tested and it came back fine.

Mind you, it's running just fine now (once the engine is warm). One of my last posts was a status update for the benefit of the forums. Honestly I think what did it (and this is embarrassing) is that I replaced the coil.

I didn't even know the 400 had an autochoke? I know it has a manual choke

I know my 2006 AC’s have it not sure about 2003 models. Sorry, I edited my last post as I had time to go back though and read your whole write up.
Yeah that sucks..my CDI actually was good but the pin that is high voltage for the ignition coil was really burnt up just from the years, I took and scratched the surfaces of that pin very carefully. But yours is definitely some other issue.. have you checked your ring gap on piston? Not sure if you’re wanting to do that or not..maybe the compression is no good on cold start?

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660catman

· #16 · 9 d ago

03’s have manual chokes. I have the exact same machine.

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Farrix

· #17 · 9 d ago

Did you purchase and install a Tach? (Wondering where RPM estimate is from) factory rpm setting is about 1250-1350 at idle. I find on cold starts I sometimes turn mine up a bit till it's warm and turn it down again after.

Are you pumping the primer?

Have you set the fuel screw with the machine running to ensure ideal mixture?

Check your plug color at idle again now that you can get it running.

I adjust my carb with the changes of the season and riding areas

Reactions: 2

roder

Discussion Starter · #18 · 5 d ago

Farrix said:
Did you purchase and install a Tach? (Wondering where RPM estimate is from) factory rpm setting is about 1250-1350 at idle.

Yeah, I purchased this digital tach. It worked OK, so I returned it. Anyhow, I did it many months ago and I don't remember the exact results - so I don't really recall.

find on cold starts I sometimes turn mine up a bit till it's warm and turn it down again after.

yeah, this makes sense. I'm doing this to get it warmed up - I give it some throttle at idle to just to get the case warmed up. Once I do, it runs fine. It's been much easier this time of year, than in winter.

Are you pumping the primer?

I don't think I have a primer? I'm not aware of anything on the carb or anything in between the tank and carb.

Have you set the fuel screw with the machine running to ensure ideal mixture?

Yep, the dealer helped me dial that in.

Check your plug color at idle again now that you can get it running.

I adjust my carb with the changes of the season and riding areas

Great ideas!

Farrix

· #19 · 4 d ago

roder said:
Yeah, I purchased this digital tach. It worked OK, so I returned it. Anyhow, I did it many months ago and I don't remember the exact results - so I don't really recall.

yeah, this makes sense. I'm doing this to get it warmed up - I give it some throttle at idle to just to get the case warmed up. Once I do, it runs fine. It's been much easier this time of year, than in winter.

I don't think I have a primer? I'm not aware of anything on the carb or anything in between the tank and carb.

Yep, the dealer helped me dial that in.

Great ideas!

This is the type of Tach that I got, one that I permanently mounted to the machine so I can keep an eye on things and understand where my rpm is at all the time.

There should be a little lever on the right side of the carb with a hole in it, that's the primer pump. shoots a jet of fuel up into the carb body to reduce the duration for it to form vacuum and start pulling fuel up.

Reactions: 1

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